Develop Reference

How to move all controls on a form based on mouse movement at runtime

I am having a bit of a small issue performing a certain task in my winforms application.
I am basically attempting to recreate a "Top-View RTS Map", on a winform. In order to save memory, not all tiles of the "Map" are displayed on the screen. Only the ones that fit within the viewport. Therefore, I am trying to allow the user to perform a pan/scroll on the displayed tiles in order to navigate the entire map!
Right now, I am doing this by creating and displaying GroupBox controls dynamically at runtime. These represent the tiles...
I have created my own objects to support all of this (contains screen coordinates, Row and Col info, etc.)
Here is how I am currently accomplishing all of this, in pseudo-code:
Creating the form, tiles and the map in general
I create a winforms form that is 600px X 600px.
I create a new "Map" (using a List<MapTile>) that is 100 tiles by 100 tiles (for testing) on form load and save that into a variable.
I keep track of the displayed tiles via another list (or property that derives from the main list bool MapTile.isDrawn)
Each tile is visually made of a GroupBox control that is 100px
X 100px (so [7 X 7] of them fit on screen)
To start, I find the center MapTile (tile [50, 50]) in the "Map", create the GroupBox for it and place that in the middle of the form,
I then add the other tiles/controls necessary to fill in the form (center - 3 tiles, center + 3 tiles (up, down, left, and right)).
Each tile, of course, subscribes to the proper mouse events to perform a drag
When the user mouse drags a tile, all other tiles being displayed follow suit/follow the leader by updating all "displayed tiles" coordinates to match the movement that was made by the "dragged" tile.
Managing Displayed Tiles
While the GroupBox tiles are being dragged/moved, I perform a check to see if the tiles that are on the outer edge of the viewport are within its bounds.
If, as an example, the top-left-most tile's right edge falls outside the bounds of the left edge of the viewport, I remove the entire left column tiles, and add the entire right column tiles programmatically. The same goes all directions (up, down, left and right).
So far, this works fine as long as I don't go too fast... however, when I drag the tiles "too fast" passed an outer edge (e.g.: where point 2 ci-dessus would apply), it seems that the application is unable to keep up because it doesn't add the column or row where they should be on the form, and other times, it does not have time to remove all controls of a row or column and I end up with controls that are still on the screen when they shouldn't be there. At that point the entire grid/map is off balance and stops working as intended because either the events that should fire on one edge don't (the tiles are not present) and/or there are now multiple controls with the same name on the form and the removal or referencing fails...
While I am well aware that winforms is not designed to perform intensive GPU/GDI operations, you would think that something this simple would still be easily do-able in winforms?
How would I go about making this more responsive at runtime? Here's my entire set of code:
Form code
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace RTSAttempt
{
public enum DrawChange
{
None,
Rem_First_Draw_Last,
Rem_Last_Draw_First
};
public partial class Form1 : Form
{
public string selected { get; set; }
private int _xPos { get; set; }
private int _yPos { get; set; }
private bool _dragging { get; set; }
public List<MapTile> mapTiles { get; set; }
public List<MapTile> drawnTiles { get { return this.mapTiles.Where(a => a.Drawn == true).ToList(); } }
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
//init globals
this.selected = "";
this._dragging = false;
this.mapTiles = new List<MapTile>();
//for testing, let's do 100 x 100 map
for (int i = 0; i < 100; i++)
{
for (int x = 0; x < 100; x++)
{
MapTile tile = new MapTile(x, i, false, -1, -1, false);
this.mapTiles.Add(tile);
}
}
GenerateStartupTiles();
}
/// <summary>
/// Used to generate the first set of map tiles on screen and dispaly them.
/// </summary>
private void GenerateStartupTiles()
{
//find center tile based on list size
double center = Math.Sqrt(this.mapTiles.Count);
//if not an even number of map tiles, we take the next one after the root.
if (this.mapTiles.Count % 2 != 0)
center += 1;
//now that we have the root, we divide by 2 to get the true center tile.
center = center / 2;
//get range of tiles to display...
int startat = (int)center - 3;
int endat = (int)center + 3;
//because the screen is roughly 600 by 600, we can display 7 X 7 tiles...
for (int row = 0; row < 7; row++)
{
for (int col = 0; col < 7; col++)
{
//get the current tile we are trying to display.
MapTile tile = mapTiles.First(a => a.Row == (startat + row) && a.Col == (startat + col));
//create and define the GroupBox control we use to display the tile on screen.
GroupBox pct = new GroupBox();
pct.Width = 100;
pct.Height = 100;
//find start position on screen
if (row == 0)
pct.Top = -50;
else
pct.Top = -50 + (row * 100);
if (col == 0)
pct.Left = -50;
else
pct.Left = -50 + (col * 100);
tile.X = pct.Left;
tile.Y = pct.Top;
pct.Name = tile.ID;
pct.Tag = Color.LightGray;
//subscribe to necessary events.
pct.MouseEnter += Pct_MouseEnter;
pct.MouseLeave += Pct_MouseLeave;
pct.Click += Pct_Click;
pct.Paint += Pct_Paint;
pct.MouseDown += Pct_MouseDown;
pct.MouseMove += Pct_MouseMove;
pct.MouseUp += Pct_MouseUp;
pct.Text = tile.DisplayID;
//add the tile to the screen
this.Controls.Add(pct);
//set the tile to Drawn mode...
tile.Drawn = true;
}
}
}
private void Pct_MouseUp(object sender, MouseEventArgs e)
{
//self explanatory
if (this._dragging)
{
Cursor.Current = Cursors.Default;
this._dragging = false;
}
}
private void Pct_MouseMove(object sender, MouseEventArgs e)
{
var c = sender as GroupBox;
if (!_dragging || null == c) return;
//get original position, and movement step/distance for calcs.
int newTop = e.Y + c.Top - _yPos;
int newLeft = e.X + c.Left - _xPos;
int movedByX = this.drawnTiles.First(a => a.ID.ToString() == c.Name).X;
int movedByY = this.drawnTiles.First(a => a.ID.ToString() == c.Name).Y;
movedByY = newTop - movedByY;
movedByX = newLeft - movedByX;
//perform all tile movements here
MoveAllTiles(movedByX, movedByY);
}
/// <summary>
/// This method performs all tile movements on screen, and updates the listing properly.
/// </summary>
/// <param name="X">int - the amount fo pixels that the dragged tile has moved horizontally</param>
/// <param name="Y">int - the amount fo pixels that the dragged tile has moved vertically</param>
private void MoveAllTiles(int X, int Y)
{
//used to single out the operation, if any, that we need to do after this move (remove row or col, from edges)
DrawChange colAction = DrawChange.None;
DrawChange rowAction = DrawChange.None;
//move all tiles currently being displayed first...
for (int i = 0; i < this.drawnTiles.Count; i++)
{
//first, determine new coordinates of tile.
drawnTiles[i].Y = drawnTiles[i].Y + Y;
drawnTiles[i].X = drawnTiles[i].X + X;
//find the control
GroupBox tmp = this.Controls.Find(drawnTiles[i].ID, true)[0] as GroupBox;
//perform screen move
tmp.Top = drawnTiles[i].Y;
tmp.Left = drawnTiles[i].X;
tmp.Refresh();
}
//dtermine which action to perform, if any...
if (drawnTiles.Last().Y > this.Height)
rowAction = DrawChange.Rem_Last_Draw_First;
else if ((drawnTiles.First().Y + 100) < 0)
rowAction = DrawChange.Rem_First_Draw_Last;
else
rowAction = DrawChange.None;
if ((drawnTiles.First().X + 100) < 0)
colAction = DrawChange.Rem_First_Draw_Last;
else if (drawnTiles.Last().X > this.Width)
colAction = DrawChange.Rem_Last_Draw_First;
else
colAction = DrawChange.None;
//get currently dispalyed tile range.
int startRow = this.drawnTiles.First().Row;
int startCol = this.drawnTiles.First().Col;
int endRow = this.drawnTiles.Last().Row;
int endCol = this.drawnTiles.Last().Col;
//perform the correct action(s), if necessary.
if (rowAction == DrawChange.Rem_First_Draw_Last)
{
//remove the first row of tiles from the screen
this.drawnTiles.Where(a => a.Row == startRow).ToList().ForEach(a => { a.Drawn = false; this.Controls.RemoveByKey(a.ID); this.Refresh(); });
//add the last row of tiles on screen...
List<MapTile> TilesToAdd = this.mapTiles.Where(a => a.Row == endRow + 1 && a.Col >= startCol && a.Col <= endCol).ToList();
int newTop = this.drawnTiles.Last().Y + 100;
for (int i = 0; i < TilesToAdd.Count; i++)
{
int newLeft = (i == 0 ? drawnTiles.First().X : drawnTiles.First().X + (i * 100));
//create and add the new tile, and set it to Drawn = true.
GroupBox pct = new GroupBox();
pct.Name = TilesToAdd[i].ID.ToString();
pct.Width = 100;
pct.Height = 100;
pct.Top = newTop;
TilesToAdd[i].Y = newTop;
pct.Left = newLeft;
TilesToAdd[i].X = newLeft;
pct.Tag = Color.LightGray;
pct.MouseEnter += Pct_MouseEnter;
pct.MouseLeave += Pct_MouseLeave;
pct.Click += Pct_Click;
pct.Paint += Pct_Paint;
pct.MouseDown += Pct_MouseDown;
pct.MouseMove += Pct_MouseMove;
pct.MouseUp += Pct_MouseUp;
pct.Text = TilesToAdd[i].DisplayID;
this.Controls.Add(pct);
TilesToAdd[i].Drawn = true;
}
}
else if (rowAction == DrawChange.Rem_Last_Draw_First)
{
//remove last row of tiles
this.drawnTiles.Where(a => a.Row == endRow).ToList().ForEach(a => { a.Drawn = false; this.Controls.RemoveByKey(a.ID); this.Refresh(); });
//add first row of tiles
List<MapTile> TilesToAdd = this.mapTiles.Where(a => a.Row == startRow - 1 && a.Col >= startCol && a.Col <= endCol).ToList();
int newTop = this.drawnTiles.First().Y - 100;
for (int i = 0; i < TilesToAdd.Count; i++)
{
int newLeft = (i == 0 ? drawnTiles.First().X : drawnTiles.First().X + (i * 100));
//create and add the new tile, and set it to Drawn = true.
GroupBox pct = new GroupBox();
pct.Name = TilesToAdd[i].ID.ToString();
pct.Width = 100;
pct.Height = 100;
pct.Top = newTop;
TilesToAdd[i].Y = newTop;
pct.Left = newLeft;
TilesToAdd[i].X = newLeft;
pct.Tag = Color.LightGray;
pct.MouseEnter += Pct_MouseEnter;
pct.MouseLeave += Pct_MouseLeave;
pct.Click += Pct_Click;
pct.Paint += Pct_Paint;
pct.MouseDown += Pct_MouseDown;
pct.MouseMove += Pct_MouseMove;
pct.MouseUp += Pct_MouseUp;
pct.Text = TilesToAdd[i].DisplayID;
this.Controls.Add(pct);
TilesToAdd[i].Drawn = true;
}
}
if (colAction == DrawChange.Rem_First_Draw_Last)
{
//remove the first column of tiles
this.drawnTiles.Where(a => a.Col == startCol).ToList().ForEach(a => { a.Drawn = false; this.Controls.RemoveByKey(a.ID); this.Refresh(); });
//add the last column of tiles
List<MapTile> TilesToAdd = this.mapTiles.Where(a => a.Col == endCol + 1 && a.Row >= startRow && a.Row <= endRow).ToList();
int newLeft = this.drawnTiles.Last().X + 100;
for (int i = 0; i < TilesToAdd.Count; i++)
{
int newTop = (i == 0 ? drawnTiles.First().Y : drawnTiles.First().Y + (i * 100));
//create and add the new tile, and set it to Drawn = true.
GroupBox pct = new GroupBox();
pct.Name = TilesToAdd[i].ID.ToString();
pct.Width = 100;
pct.Height = 100;
pct.Top = newTop;
TilesToAdd[i].Y = newTop;
pct.Left = newLeft;
TilesToAdd[i].X = newLeft;
pct.Tag = Color.LightGray;
pct.MouseEnter += Pct_MouseEnter;
pct.MouseLeave += Pct_MouseLeave;
pct.Click += Pct_Click;
pct.Paint += Pct_Paint;
pct.MouseDown += Pct_MouseDown;
pct.MouseMove += Pct_MouseMove;
pct.MouseUp += Pct_MouseUp;
pct.Text = TilesToAdd[i].DisplayID;
this.Controls.Add(pct);
TilesToAdd[i].Drawn = true;
}
}
else if (colAction == DrawChange.Rem_Last_Draw_First)
{
//remove last column of tiles
this.drawnTiles.Where(a => a.Col == endCol).ToList().ForEach(a => { a.Drawn = false; this.Controls.RemoveByKey(a.ID); this.Refresh(); });
//add first column of tiles
List<MapTile> TilesToAdd = this.mapTiles.Where(a => a.Col == startCol - 1 && a.Row >= startRow && a.Row <= endRow).ToList();
int newLeft = this.drawnTiles.First().X - 100;
for (int i = 0; i < TilesToAdd.Count; i++)
{
int newTop = (i == 0 ? drawnTiles.First().Y : drawnTiles.First().Y + (i * 100));
//create and add the new tile, and set it to Drawn = true.
GroupBox pct = new GroupBox();
pct.Name = TilesToAdd[i].ID.ToString();
pct.Width = 100;
pct.Height = 100;
pct.Top = newTop;
TilesToAdd[i].Y = newTop;
pct.Left = newLeft;
TilesToAdd[i].X = newLeft;
pct.Tag = Color.LightGray;
pct.MouseEnter += Pct_MouseEnter;
pct.MouseLeave += Pct_MouseLeave;
pct.Click += Pct_Click;
pct.Paint += Pct_Paint;
pct.MouseDown += Pct_MouseDown;
pct.MouseMove += Pct_MouseMove;
pct.MouseUp += Pct_MouseUp;
ToolTip tt = new ToolTip();
tt.SetToolTip(pct, pct.Name);
pct.Text = TilesToAdd[i].DisplayID;
this.Controls.Add(pct);
TilesToAdd[i].Drawn = true;
}
}
}
private void Pct_MouseDown(object sender, MouseEventArgs e)
{
//self explanatory
if (e.Button != MouseButtons.Left) return;
_dragging = true;
_xPos = e.X;
_yPos = e.Y;
}
private void Pct_Click(object sender, EventArgs e)
{
//changes the border color to reflect the selected tile...
if (!String.IsNullOrWhiteSpace(selected))
{
if (this.Controls.Find(selected, true).Length > 0)
{
GroupBox tmp = this.Controls.Find(selected, true)[0] as GroupBox;
ControlPaint.DrawBorder(tmp.CreateGraphics(), tmp.ClientRectangle, Color.LightGray, ButtonBorderStyle.Solid);
}
}
GroupBox pct = sender as GroupBox;
ControlPaint.DrawBorder(pct.CreateGraphics(), pct.ClientRectangle, Color.Red, ButtonBorderStyle.Solid);
this.selected = pct.Name;
}
private void Pct_Paint(object sender, PaintEventArgs e)
{
//draws the border based on the correct tag.
GroupBox pct = sender as GroupBox;
Color clr = (Color)pct.Tag;
ControlPaint.DrawBorder(e.Graphics, pct.ClientRectangle, clr, ButtonBorderStyle.Solid);
}
private void Pct_MouseLeave(object sender, EventArgs e)
{
//draws the border back to gray, only if this is not the selected tile...
GroupBox pct = sender as GroupBox;
if (this.selected != pct.Name)
{
pct.Tag = Color.LightGray;
pct.Refresh();
}
}
private void Pct_MouseEnter(object sender, EventArgs e)
{
//draws a red border around the tile to show which tile the mouse is currently hovering on...
GroupBox pct = sender as GroupBox;
pct.Tag = Color.Red;
pct.Refresh();
}
}
}
MapTile object
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace RTSAttempt
{
public class MapTile
{
/// <summary>
/// Represents the row of the tile on the map
/// </summary>
public int Row { get; set; }
/// <summary>
/// Represents the column of the tile on the map
/// </summary>
public int Col { get; set; }
/// <summary>
/// Represents the ID of this tile ([-1,-1], [0,0], [1,1], etc
/// </summary>
public string ID { get { return "Tile_" + this.Row + "_" + this.Col; } }
public string DisplayID { get { return this.Row + ", " + this.Col; } }
/// <summary>
/// If this tile is currently selected or clicked.
/// </summary>
public bool Selected { get; set; }
/// <summary>
/// Represents the X screen coordinates of the tile
/// </summary>
public int X { get; set; }
/// <summary>
/// Represents the Y screen coordinates of the tile
/// </summary>
public int Y { get; set; }
/// <summary>
/// Represents whether this tile is currently being drawn on the screen.
/// </summary>
public bool Drawn { get; set; }
public MapTile(int idCol = -1, int idRow = -1, bool selected = false, int screenX = -1, int screenY = -1, bool drawn = false)
{
this.Col = idCol;
this.Row = idRow;
this.Selected = selected;
this.X = screenX;
this.Y = screenY;
this.Drawn = drawn;
}
public override bool Equals(object obj)
{
MapTile tmp = obj as MapTile;
if (tmp == null)
return false;
return this.ID == tmp.ID;
}
public override int GetHashCode()
{
return this.ID.GetHashCode();
}
}
}

I'd create the grid using (DataGridView, TableLayoutPanel, GDI+, or whatever) and then in the drag and drop, just calculate the new indexes and update the indexes, without moving the grid.
Example
The following example shows how to do it using a TableLayoutPanel:
Assign a fixed size to cells
Build the grid to fill the form
When form resizes, rebuild the grid
In mouse down capture the mouse down point and current top left index of grid
In mouse move, calculate the new index based on mouse movement and update index
In cell paint of the panel, draw the indexes
Here is the code:
int topIndex = 0, leftIndex = 0;
int originalLeftIndex = 0, originalTopIndex = 0;
int cellSize = 100;
Point p1;
TableLayoutPanel panel;
void LayoutGrid()
{
panel.SuspendLayout();
var columns = (ClientSize.Width / cellSize) + 1;
var rows = (ClientSize.Height / cellSize) + 1;
panel.RowCount = rows;
panel.ColumnCount = columns;
panel.ColumnStyles.Clear();
panel.RowStyles.Clear();
for (int i = 0; i < columns; i++)
panel.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, cellSize));
for (int i = 0; i < rows; i++)
panel.RowStyles.Add(new RowStyle(SizeType.Absolute, cellSize));
panel.Width = columns * cellSize;
panel.Height = rows * cellSize;
panel.CellBorderStyle = TableLayoutPanelCellBorderStyle.Single;
panel.ResumeLayout();
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
panel = new MyGrid();
this.Controls.Add(panel);
LayoutGrid();
panel.MouseDown += Panel_MouseDown;
panel.MouseMove += Panel_MouseMove;
panel.CellPaint += Panel_CellPaint;
}
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
if (panel != null)
LayoutGrid();
}
private void Panel_CellPaint(object sender, TableLayoutCellPaintEventArgs e)
{
var g = e.Graphics;
TextRenderer.DrawText(g, $"({e.Column + leftIndex}, {e.Row + topIndex})",
panel.Font, e.CellBounds, panel.ForeColor);
}
private void Panel_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
var dx = (e.Location.X - p1.X) / cellSize;
var dy = (e.Location.Y - p1.Y) / cellSize;
leftIndex = originalLeftIndex - dx;
topIndex = originalTopIndex - dy;
panel.Invalidate();
}
}
private void Panel_MouseDown(object sender, MouseEventArgs e)
{
p1 = e.Location;
originalLeftIndex = leftIndex;
originalTopIndex = topIndex;
}
To prevent flicker:
public class MyGrid : TableLayoutPanel
{
public MyGrid()
{
DoubleBuffered = true;
}
}

So, for anyone trying to do this, as a concept, here is how to fix this issue:
Instead of only drawing 1 row/col extra outside the viewport to save memory, draw the entire viewport's worth of cells in every direction of the edges (up, down, left and right)... for example, if your viewport can hold 5 tiles (5 X 5 = 25), then you need to draw 5 X 5 outside the viewport in every other direction (25 X 4 = 100)...
When the mouse is being dragged, just move the controls that are already on the form/control/"drawn"... this way, the user cannot, while dragging, go outside the bounds of the existing tiles... example, if they reach the outer right edge with the mouse, while dragging the left-most tile, the tiles to show on the left already exist! So we are just "following the mouse", which is not an issue if the controls are already there/there is no "loss/issues" because we are not removing or adding any tiles at this point...
When the user stops dragging the selected tile around (onMouseUp), THEN we re-calculate the tiles that need to be drawn and those that don't... so we only redraw (add and/or remove controls where necessary) the entire set of "drawn" tiles after the user is done dragging...
With this method, you remove any "missplaced" controls, double generation of controls, controls missing and any other issue that arises when the mouse moves too fast for the "Calculate drawn tiles" code to execute. You also "see" the map moving around as you drag, and you always have the correct tiles drawn on the screen! Problem solved!
However, I did find that when I used a UserControl instead of the form itself, the controls draw and update much faster and better than if I just add them to the form itself... therefore, I have accepted the answer that outlines that aspect as the actual answer, and placed this here for anyone else in future that might wonder how to do this as a concept.

C# - show child control (Listbox) on top of parent control(textbox) in winform

Created a custom intellisense textbox (textbox with listbox a child).
As shown in below image, the listbox pops up when i enter a char which all works fine and good but when i am at the end of textbox the listbox is partially visible, is there anyway i can show the whole listbox content?
Tried this "Show control inside user control outside the boundaries of its parent
But when the popup window opens the text box looses focus and i cannot type anything further, my intellisense textbox keeps giving better results based on what they type but in this situation i am not able to type anymore.
FYI tried to add pParentControl.Focus() into show method defined in other article as shown below, missing something?
public void Show(Control pParentControl)
{
if (pParentControl == null) return;
// position the popup window
var loc = pParentControl.PointToScreen(new Point(0, pParentControl.Height));
pParentControl.Focus();
m_tsdd.Show(loc);
}
Here is the complete code
class TextBox_AutoComplete : TextBox
{
#region Class Members
List<string> dictionary;
ListBox listbox = new ListBox();
#endregion
private PopupHelper m_popup;
#region Extern functions
[DllImport("user32")]
private extern static int GetCaretPos(out Point p);
#endregion
#region Constructors
public TextBox_AutoComplete() : base()
{
this.Margin = new Padding(0, 0, 0, 0);
this.Multiline = true;
this.Dock = DockStyle.Fill;
this.KeyDown += Textbox_KeyDown;
this.KeyUp += Textbox_KeyUp;
listbox.Parent = this;
listbox.KeyUp += List_OnKeyUp;
listbox.Visible = false;
this.dictionary = new List<string>();
}
#endregion
#region Properties
public List<string> Dictionary
{
get { return this.dictionary; }
set { this.dictionary = value; }
}
#endregion
#region Methods
private static string GetLastString(string s)
{
Regex rgx = new Regex("[^a-zA-Z0-9_.\\[\\]]");
s = rgx.Replace(s, " ");
string[] strArray = s.Split(' ');
return strArray[strArray.Length - 1];
}
protected override void OnTextChanged(EventArgs e)
{
base.OnTextChanged(e);
Point cp;
GetCaretPos(out cp);
List<string> lstTemp = new List<string>();
List<string> TempFilteredList = new List<string>();
string LastString = GetLastString(this.Text.Substring(0, SelectionStart));
//MessageBox.Show(LastString);
/*seperated them so that column name matches are found first*/
TempFilteredList.AddRange(dictionary.Where(n => n.Replace("[", "").ToUpper().Substring(n.IndexOf(".") > 0 ? n.IndexOf(".") : 0).StartsWith(LastString.ToUpper())
).Select(r => r)
.ToList());
TempFilteredList.AddRange(dictionary.Where(n => n.Replace("[", "").ToUpper().StartsWith(LastString.ToUpper())
|| n.ToUpper().StartsWith(LastString.ToUpper()))
.Select(r => r)
.ToList());
lstTemp = TempFilteredList.Distinct().Select(r => r).ToList();
/*Getting max width*/
int maxWidth = 0, temp = 0;
foreach (var obj in lstTemp)
{
temp = TextRenderer.MeasureText(obj.ToString(), new Font("Arial", 10, FontStyle.Regular)).Width;
if (temp > maxWidth)
{
maxWidth = temp;
}
}
listbox.SetBounds(cp.X + 20, cp.Y + 20, maxWidth, 60);
if (lstTemp.Count != 0 && LastString != "")
{
listbox.DataSource = lstTemp;
// listbox.Show();
if (m_popup == null)
m_popup = new PopupHelper(listbox);
m_popup.Show(this);
}
else if (m_popup != null)
{
//listbox.Hide();
m_popup.Hide();
}
}
protected void Textbox_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Down)
{
if (listbox.Visible == true)
{
listbox.Focus();
}
e.Handled = true;
}
else if (e.KeyCode == Keys.Escape)
{
listbox.Visible = false;
e.Handled = true;
}
}
protected void Textbox_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Space && listbox.Visible == true)
{
listbox.Focus();
List_OnKeyUp(listbox, new KeyEventArgs(Keys.Space));
e.Handled = true;
}
if (e.KeyCode == Keys.Down && listbox.Visible == true)
{
listbox.Focus();
e.Handled = true;
}
}
private void List_OnKeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Space || e.KeyCode == Keys.Enter)
{
int Selection_Start = this.SelectionStart;
string StrLS = GetLastString(this.Text.Substring(0, Selection_Start));
this.Select(Selection_Start - StrLS.Length, StrLS.Length);
// MessageBox.Show(this.Selection_Start.ToString() + " Last string" + StrLS);
this.SelectedText=((ListBox)sender).SelectedItem.ToString();
listbox.Hide();
this.Focus();
}
}
#endregion
}
public sealed class PopupHelper : IDisposable
{
private readonly Control m_control;
private readonly ToolStripDropDown m_tsdd;
private readonly Panel m_hostPanel; // workarround - some controls don't display correctly if they are hosted directly in ToolStripControlHost
public PopupHelper(Control pControl)
{
m_hostPanel = new Panel();
m_hostPanel.Padding = Padding.Empty;
m_hostPanel.Margin = Padding.Empty;
m_hostPanel.TabStop = false;
m_hostPanel.BorderStyle = BorderStyle.None;
m_hostPanel.BackColor = Color.Transparent;
m_tsdd = new ToolStripDropDown();
m_tsdd.CausesValidation = false;
m_tsdd.Padding = Padding.Empty;
m_tsdd.Margin = Padding.Empty;
m_tsdd.Opacity = 0.9;
m_control = pControl;
m_control.CausesValidation = false;
m_control.Resize += MControlResize;
//m_hostPanel.Controls.Add(m_control);
m_tsdd.Padding = Padding.Empty;
m_tsdd.Margin = Padding.Empty;
m_tsdd.MinimumSize = m_tsdd.MaximumSize = m_tsdd.Size = pControl.Size;
m_tsdd.Items.Add(new ToolStripControlHost(m_control));
}
private void ResizeWindow()
{
m_tsdd.MinimumSize = m_tsdd.MaximumSize = m_tsdd.Size = m_control.Size;
m_hostPanel.MinimumSize = m_hostPanel.MaximumSize = m_hostPanel.Size = m_control.Size;
}
private void MControlResize(object sender, EventArgs e)
{
ResizeWindow();
}
/// <summary>
/// Display the popup and keep the focus
/// </summary>
/// <param name="pParentControl"></param>
public void Show(Control pParentControl)
{
if (pParentControl == null) return;
// position the popup window
var loc = pParentControl.PointToScreen(new Point(0, pParentControl.Height));
pParentControl.Focus();
m_tsdd.Show(loc);
}
public void Hide()
{
m_tsdd.Hide();
}
public void Close()
{
m_tsdd.Close();
}
public void Dispose()
{
m_control.Resize -= MControlResize;
m_tsdd.Dispose();
m_hostPanel.Dispose();
}
}

Firstly, I personally don't see any benefit in having a control inside another. Yes, the child control is locked inside its parent's boundaries automatically for you, but this benefit is negated by the issue that you're facing, and solving that issue requires the same work as when the two controls have no relation. In both cases, you'll have to do the calculations manually to keep the child visible inside its parent. In the second case the parent is the app's window.
Secondly, I don't recommend using hacks like the one mentioned in the comments to show the child outside its parent's boundaries. The hack creates more issues than it solves, as you found out. And what's the point of that hack anyway? If you want to show the child outside the parent, then don't make it a child control in the first place, and you don't need any hack.
The best solution is the one that you find in any well designed app, and in Windows itself. Open any app, let's say Notepad, and right-click near the upper-left corner. You'll see the context menu pulling to lower-right direction. Now right-click near the other three corners and you'll see the context menu pulling in different direction each time, so it will always be visible inside the app. Now if you resize the app window too small and right-click, the context menu will choose the best direction but some of it will be outside the app because the window is too small. That's why you need your list not to be a child, but it's up to you, and it's only about these edge cases. The solution will be similar in both cases.
You're displaying the list in this line:
listbox.SetBounds(cp.X + 20, cp.Y + 20, maxWidth, 60);
The key is cp.X and cp.Y. This is what decides where the list will appear. You need to make this point dynamic and responsive to the boundaries of the parent. You fixed the width to maxWidth and height to 60, so I will use those values in the calculation.
To make sure the list will not go beyond the bottom:
var y = this.Height < cp.Y + 60 ? this.Height - 60 : cp.Y;
To make sure the list will not go beyond the right:
var x = this.Width < cp.X + maxWidth ? this.Width - maxWidth : cp.X;
Now you can show your list at the calculated point:
listbox.SetBounds(x, y, maxWidth, 60);
Notes:
I didn't include the 20 gap that you used. I think it looks better without the gap and I haven't seen any app that has a gap. If you prefer the gap, add it to the calculation of x and y. Don't add it in the SetBounds() or that will screw up the calculation.
The calculation above doesn't take into account when the parent size is too small to show the child inside. If you want to support that edge case, you need to make the child a separate control and add some checks to the calculation.

TeeChart: Expand the "clickable" width of a Line/FastLine

I have a WinForms application where a number of lines are drawn in a TeeChart component. It is requested that it shall be possible to delete a line by right-clicking it.
Everything works fine, the clickseries event is captured and so on, but the user finds it difficult to hit the line on right click. The question is, is it possible to increase the region where the Line/FastLine object is sensible for clicking? That is, make the line wider without drawing the line any wider on the screen.
Tnx in advance

Yes, this is possible. The key to achieve that is PointInLineTolerance method. To achieve what you request you can combine it with NearestPoint's tool GetNearestPoint method as shown in this example:
public Form1()
{
InitializeComponent();
InitializeChart();
}
private void InitializeChart()
{
tChart1.Aspect.View3D = false;
tChart1.Series.Add(new Steema.TeeChart.Styles.Line()).FillSampleValues();
tChart1.MouseMove += TChart1_MouseMove;
}
private void TChart1_MouseMove(object sender, MouseEventArgs e)
{
var nearestPoint = new Steema.TeeChart.Tools.NearestPoint(tChart1[0]);
nearestPoint.Active = false;
var p = new Point(e.X, e.Y);
var index = nearestPoint.GetNearestPoint(p);
if (index != -1)
{
const int tolerance = 10;
var px = tChart1[0].CalcXPos(index);
var py = tChart1[0].CalcYPos(index);
var index2 = (index == tChart1[0].Count - 1) ? index - 1 : index + 1;
var qx = tChart1[0].CalcXPos(index2);
var qy = tChart1[0].CalcYPos(index2);
if (Steema.TeeChart.Drawing.Graphics3D.PointInLineTolerance(p, px, py, qx, qy, tolerance))
{
tChart1.Header.Text = "point " + index.ToString() + " clicked";
}
else
{
tChart1.Header.Text = "No point";
}
}
An alternative could be using an invisible fake series with same data as the original series.

C# .net Make listview items clickable

I am trying to click on items in the listview. Is there a way to do this? I would like to click on each one individually (and from that action, write to hardware, change the on/off indication (bold font), and update the hex value for that register.
I've found how to click on the columns via msdn, but I cannot figure out how to click on the items. http://msdn.microsoft.com/en-us/library/system.windows.forms.listview.oncolumnclick
I don't have much experience, but it seems like I should be able to interface from Control.Onclick somehow: http://msdn.microsoft.com/en-us/library/system.windows.forms.control.onclick(v=vs.110).aspx

Try this Code.
Handle the ListView_MouseUp event and write down the following code.
private void listView1_MouseUp(object sender, MouseEventArgs e)
{
if (listView1.View != View.Details)
return;
int rowIndex = getRowIndex(e.Location);
if (rowIndex == -1)
return ;
int columnIndex = getColumnIndex(e.Location);
if (columnIndex > -1)
OnCellClick(rowIndex, columnIndex);
}
Now, create the method to get the Column Index according to mouse position. This method will find the column index according to mouse position.
private int getColumnIndex(Point p)
{
Rectangle r = Rectangle.Empty;
r = Rectangle.Empty;
for (int i = 0; i < listView1.Columns.Count; i++)
{
r = new Rectangle(r.X + r.Width, 0, listView1.Columns[i].Width, listView1.Height);
if (r.Contains(p))
return i;
}
return -1;
}
Create another method to get the Row Index according to mouse position. This method will find the row index according to mouse position and it will set the FocusedItem property of ListView. So, you can get the focus on the clicked item.
private int getRowIndex(Point p)
{
Rectangle r = Rectangle.Empty;
for (int i = 0; i < listView1.Items.Count; i++)
{
Rectangle r1 = listView1.GetItemRect(i);
r = new Rectangle(0, r1.Top, listView1.Width, r1.Height);
if (r.Contains(p))
{
listView1.FocusedItem = listView1.Items[i];
return i;
}
}
return -1;
}
This is the method that you need to handle. Your code to get the value from ListView cell will be written in this method.
private void OnCellClick(int RowIndex, int ColumnIndex)
{
MessageBox.Show("Column : " + ColumnIndex.ToString() + ", Row: " + RowIndex.ToString());
}
I know there is no need to create method to get the RowIndex. We can get the Item directly from location by using GetItemAt(x,y) method. But, this method only works when you have set the FullRowSelect to true otherwise you will get null when the mouse position is on subitem.

How to prevent user to enter a special character in text box?

I want to prevent one particular character * (asterisk) from being entered or pasted into a text box.
I tried:
key_press event - but it does not handle the case when user pastes an asterisk to the text box.
text_changed event - but when I remove the character, the cursor position goes back to the beginning of the text.
So I am wondering how to handle it, preferably in one event.

use the text changed event, but save the location of the cursor (the SelectionStart and SelectionEnd properties) before you remove the asterisk, then re set the cursor position (less the number of asterisks removed before the cursor).
private void textBox1_TextChanged(object sender, TextChangedEventArgs e)
{
var currentText = textBox1.Text;
var selectionStart = textBox1.SelectionStart;
var selectionLength = textBox1.SelectionLength;
int nextAsterisk;
while ((nextAsterisk = currentText.IndexOf('*')) != -1)
{
if (nextAsterisk < selectionStart)
{
selectionStart--;
}
else if (nextAsterisk < selectionStart + selectionLength)
{
selectionLength--;
}
currentText = currentText.Remove(nextAsterisk, 1);
}
if (textBox1.Text != currentText)
{
textBox1.Text = currentText;
textBox1.SelectionStart = selectionStart;
textBox1.SelectionLength = selectionLength;
}
}

This question may be of use to you. What you're looking for seems like either a MaskedTextBox or a TextBox with custom Validation logic. You should not simply erase an asterisk characters when it is input, because if a user has selected text, then typed an asterisk, they will have replaced the selected text with an asterisk before you have the chance to remove it.

You can set the cursor postion. For example:
textBox1.SelectionStart = textBox1.Text.Length;
EDIT:
Ok i took some time to write you a solution that works quite good. It keeps the edit cursor at the proper position and also covers the situation in which user pastes some * chars between chars.
int position = this.textBox1.SelectionStart;
string str = this.textBox1.Text;
int hit = 0;
for (int i = 0; i < position; i++)
{
if (str[i].Equals('*'))
hit++;
}
str = str.Replace("*", "");
this.textBox1.Text = str;
this.textBox1.SelectionLength = 0;
this.textBox1.SelectionStart = position - hit;

Here is the solution i found:-
On Text_changed event, here is what i am doing:-
txt1.Text = txt1.Text.Replace("*", string.Empty);
txt1.Select(txt1.Text.Length, 0);
Updated code:-
On Text_changed event:-
int curpos = 0;
bool isReplaced = false;
private void txt1_TextChanged(object sender, EventArgs e)
{
if (txt1.Text.Contains('*'))
{
curpos = txt1.SelectionStart;
isReplaced = true;
}
txt1.Text = txt1.Text.Replace("*", string.Empty);
if (isReplaced)
{
txt1.Select(curpos.Equals(0) ? 0 : curpos -1, 0);
isReplaced = false;
}
}
Final code and Tested :-
if (txt1.Text.Contains('*'))
{
foreach (char c in txt1.Text)
if (c.Equals('*'))
barredCharCount += 1;
curPosition = txt1.SelectionStart;
isTextReplaced = true;
}
txt1.Text = txt1.Text.Replace("*", string.Empty);
if (isTextReplaced)
{
txt1.Select(curPosition.Equals(0) ? 0 : curPosition - barredCharCount, 0);
isTextReplaced = false;
curPosition = barredCharCount = 0;
Console.Beep(); //does not work on 64 bit system
}
This piece of code is tested and working perfectly...