Develop Reference

How to at runtime allow a user to create a new Picturebox Visual Studio C# Windows Forms Apps

I am trying to create a Form in Visual Studio Windows Forms Apps C# in which during runtime the user or operator can create a new picturebox with a left mouse click and then have the ability to move each picturebox created.
I really do not know where to begin. Anyone have any ideas?

To add a new PictureBox dynamically, you can subscribe to the event Form_MouseClick and create the PictureBox like this:
public Form1()
{
InitializeComponent();
this.MouseClick += Form_MouseClick;
}
private void Form_MouseClick(object sender, MouseEventArgs e)
{
PictureBox pictureBox = new PictureBox();
// cursor location
pictureBox.Location = new Point(e.X, e.Y);
pictureBox.BackColor = Color.Red;
this.Controls.Add(pictureBox);
}
To drag and move the PictureBox, you also nee to subscribe to the event MouseDown, MouseUp, and MouseMove.
Here is a simple demo you can refer to.
private void Form_MouseClick(object sender, MouseEventArgs e)
{
// create new control
PictureBox pictureBox = new PictureBox();
pictureBox.Location = new Point(e.X, e.Y);
pictureBox.BackColor = Color.Red;
this.Controls.Add(pictureBox);
// bind event for each PictureBox
pictureBox.MouseDown += pictureBox_MouseDown;
pictureBox.MouseUp += pictureBox_MouseUp;
pictureBox.MouseMove += pictureBox_MouseMove;
}
Point mouseDownPoint = Point.Empty;
Rectangle rect = Rectangle.Empty;
bool isDrag = false;
private void pictureBox_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
mouseDownPoint = e.Location;
rect = (sender as PictureBox).Bounds;
}
}
private void pictureBox_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
if (isDrag)
{
isDrag = false;
(sender as PictureBox).Location = rect.Location;
this.Refresh();
}
reset();
}
}
private void pictureBox_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
isDrag = true;
rect.Location = this.PointToClient((sender as PictureBox).PointToScreen(new Point(e.Location.X - mouseDownPoint.X, e.Location.Y - mouseDownPoint.Y)));
this.Refresh();
}
}
private void reset()
{
mouseDownPoint = Point.Empty;
rect = Rectangle.Empty;
isDrag = false;
}

You can add the form elements during runtime:
var picture = new PictureBox
{
Name = "pictureBox",
Size = new Size(16, 16),
Location = new Point(100, 100),
Image = Image.FromFile("test.jpg"),
};
this.Controls.Add(picture);
Afterward, you can move it with the Mouse Events

C#. How to avoid double click when I need single click

I am developing a windows form application. Creating a UI for some service. What is happening is when I created the application there are various buttons on which a single click should work to get and set the value but after the completion of code all those buttons are reacting on double click.
when we apply some break point and test, values get and set in single click only but during run-time it need double click. Can anybody help?

I got the solution by writing a piece of code.
Just activated the button on first click.
bool firstClick = true;
{if(firstClick) { button.select(); //Activating the button } }
Thanks all for your responses.

Here is a full Article from MSDN on how to use single-click only vs double-click only. Also, it states how you can handle events and differentiate between a single click and a double click.
The article uses boolean and timers to do that. You might need to use a Dictionary<Button, boolean> if you have multiple buttons. Hope it helps.
Here is the example if the link got down or removed for some reaosn:
Handle the MouseDown event and determine the location and time span
between clicks using the appropriate SystemInformation properties and
a Timer component. Perform the appropriate action depending on whether
a click or double-click takes place. The following code example
demonstrates how this can be done.
class Form1 : Form
{
private Rectangle hitTestRectangle = new Rectangle();
private Rectangle doubleClickRectangle = new Rectangle();
private TextBox textBox1 = new TextBox();
private Timer doubleClickTimer = new Timer();
private ProgressBar doubleClickBar = new ProgressBar();
private Label label1 = new Label();
private Label label2 = new Label();
private bool isFirstClick = true;
private bool isDoubleClick = false;
private int milliseconds = 0;
[STAThread]
public static void Main()
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
public Form1()
{
label1.Location = new Point(30, 5);
label1.Size = new Size(100, 15);
label1.Text = "Hit test rectangle:";
label2.Location = new Point(30, 70);
label2.Size = new Size(100, 15);
label2.Text = "Double click timer:";
hitTestRectangle.Location = new Point(30, 20);
hitTestRectangle.Size = new Size(100, 40);
doubleClickTimer.Interval = 100;
doubleClickTimer.Tick +=
new EventHandler(doubleClickTimer_Tick);
doubleClickBar.Location = new Point(30, 85);
doubleClickBar.Minimum = 0;
doubleClickBar.Maximum = SystemInformation.DoubleClickTime;
textBox1.Location = new Point(30, 120);
textBox1.Size = new Size(200, 100);
textBox1.AutoSize = false;
textBox1.Multiline = true;
this.Paint += new PaintEventHandler(Form1_Paint);
this.MouseDown += new MouseEventHandler(Form1_MouseDown);
this.Controls.AddRange(new Control[] { doubleClickBar, textBox1,
label1, label2 });
}
// Detect a valid single click or double click.
void Form1_MouseDown(object sender, MouseEventArgs e)
{
// Verify that the mouse click is in the main hit
// test rectangle.
if (!hitTestRectangle.Contains(e.Location))
{
return;
}
// This is the first mouse click.
if (isFirstClick)
{
isFirstClick = false;
// Determine the location and size of the double click
// rectangle area to draw around the cursor point.
doubleClickRectangle = new Rectangle(
e.X - (SystemInformation.DoubleClickSize.Width / 2),
e.Y - (SystemInformation.DoubleClickSize.Height / 2),
SystemInformation.DoubleClickSize.Width,
SystemInformation.DoubleClickSize.Height);
Invalidate();
// Start the double click timer.
doubleClickTimer.Start();
}
// This is the second mouse click.
else
{
// Verify that the mouse click is within the double click
// rectangle and is within the system-defined double
// click period.
if (doubleClickRectangle.Contains(e.Location) &&
milliseconds < SystemInformation.DoubleClickTime)
{
isDoubleClick = true;
}
}
}
void doubleClickTimer_Tick(object sender, EventArgs e)
{
milliseconds += 100;
doubleClickBar.Increment(100);
// The timer has reached the double click time limit.
if (milliseconds >= SystemInformation.DoubleClickTime)
{
doubleClickTimer.Stop();
if (isDoubleClick)
{
textBox1.AppendText("Perform double click action");
textBox1.AppendText(Environment.NewLine);
}
else
{
textBox1.AppendText("Perform single click action");
textBox1.AppendText(Environment.NewLine);
}
// Allow the MouseDown event handler to process clicks again.
isFirstClick = true;
isDoubleClick = false;
milliseconds = 0;
doubleClickBar.Value = 0;
}
}
// Paint the hit test and double click rectangles.
void Form1_Paint(object sender, PaintEventArgs e)
{
// Draw the border of the main hit test rectangle.
e.Graphics.DrawRectangle(Pens.Black, hitTestRectangle);
// Fill in the double click rectangle.
e.Graphics.FillRectangle(Brushes.Blue, doubleClickRectangle);
}
}

You can simply identify single click and double using a timer. Here is the example
class Form1 : Form
{
Timer timer;
public Form1()
{
InitializeComponent();
timer = new Timer();
timer.Interval = 500;
timer.Tick += new EventHandler(Timer_Tick);
}
private void App_MouseDown(object sender, MouseEventArgs e)
{
if (e.Clicks == 1)
{
timer.Start();
}
else
{
timer.Stop();
doubleClick();
}
}
private void Timer_Tick(object sender, EventArgs e)
{
timer.Stop();
singleClick();
}
//Single click
public void singleClick()
{
MessageBox.Show("Single Click.");
}
//Double click
public void doubleClick()
{
MessageBox.Show("Double Click.");
}
}

How to show text box on mouse move c#

I want to show a inherited text box control on mouse over on the form. But text is not displayed. Below is my code.
private ChartCalloutBox m_calloutbox = null;
public Form2()
{
InitializeComponent();
this.MouseMove += Form2_MouseMove;
}
void Form2_MouseMove(object sender, MouseEventArgs e)
{
if (m_calloutbox == null)
{
m_calloutbox = new ChartCalloutBox();
}
m_calloutbox.Location = e.Location;
m_calloutbox.Show();
}
internal class ChartCalloutBox : TextBox
{
public ChartCalloutBox()
{
InitializeComponent();
}
private void InitializeComponent()
{
this.SuspendLayout();
this.Location = new System.Drawing.Point(350, 170);
this.ClientSize = new System.Drawing.Size(130, 40);
this.Size = new System.Drawing.Size(130, 40);
this.BackColor = System.Drawing.Color.Black;
this.ForeColor = System.Drawing.Color.Brown;
this.Name = "CalloutBox";
this.Text = "Callout Rect";
this.ResumeLayout(false);
//
}
}
Any one help on this how to show the text box on mouse over. and the text box place should be change based on the mouse position.
Thanks,
Bharathi.

Add your control to controls collection.
Code should be like
void Form2_MouseMove(object sender, MouseEventArgs e)
{
if (m_calloutbox == null)
{
m_calloutbox = new ChartCalloutBox();
this.Controls.Add(m_calloutbox);
}
m_calloutbox.Location = e.Location;
}

C# drag controls around a panel

i am developing a system which allow user to drag objects around within a same panel, i went through some research and founds that i should use mouse events like mouse_up, mouse_down and mouse_move.
The the program will generate 3 picturebox and allow the user to drag around the every picturebox within the panel, but the program i code did not work perfectly as when i drag over a picturebox, the picturebox will move, but not according to my mouse cursor location, it is somewhere else, besides, when dragging, there is picturebox shadows in the panel, i've tried those update(),refresh(), and invalidate() but it seems not useful for me. Below are my codes, thanks for helping
public partial class Form1 : Form
{
List<PictureBox> pictureBoxList = new List<PictureBox>();
private bool isDragging = false;
public Form1()
{
InitializeComponent();
for (int i = 0; i < 3; i++)
{
PictureBox picture = new PictureBox
{
Name = "pictureBox" + i,
Size = new Size(20, 20),
Location = new Point(i * 40, i * 40),
BorderStyle = BorderStyle.FixedSingle,
SizeMode = PictureBoxSizeMode.Zoom,
ImageLocation = "A.jpg"
};
pictureBoxList.Add(picture);
foreach (PictureBox p in pictureBoxList)
{
p.MouseDown += new MouseEventHandler(c_MouseDown);
p.MouseMove += new MouseEventHandler(c_MouseMove);
p.MouseUp += new MouseEventHandler(c_MouseUp);
pnlDisplayImage.Controls.Add(p);
pnlDisplayImage.Refresh();
}
}
}
void c_MouseDown(object sender, MouseEventArgs e)
{
isDragging = true;
}
void c_MouseMove(object sender, MouseEventArgs e)
{
if (isDragging == true) {
Control c = sender as Control;
for (int i = 0; i < pictureBoxList.Count(); i++)
{
if (c.Equals(pictureBoxList[i]))
{
pictureBoxList[i].Location = new Point(e.X, e.Y);
}
}
}
}
void c_MouseUp(object sender, MouseEventArgs e)
{
PictureBox c = sender as PictureBox;
isDragging = false;
for (int i = 0; i < pictureBoxList.Count(); i++) {
if (c.Equals(pictureBoxList[i])){
pictureBoxList[i].Location = new Point(e.X, e.Y);
}
}
}
private void pnlDisplayImage_Paint(object sender, PaintEventArgs e)
{
foreach (PictureBox p in pictureBoxList)
{
pnlDisplayImage.Controls.Add(p);
}
}
}

Finally I've found what are the problems that caused my program not running as my expectations. The main problem is that I accidentally put the foreach loop inside the for loop which I used to create pictureBox, this problem caused the pictureBox comes out some shadows effect while dragging during run time due to there are few same pictureBox. Also, I have change a little bit of the codes and it now run as what I expected. Below are the code that I want for answer.
public partial class Form1 : Form
{
List<PictureBox> pictureBoxList = new List<PictureBox>();
private bool isDragging = false;
Point move;
public Form1()
{
InitializeComponent();
for (int i = 0; i < 3; i++)
{
PictureBox picture = new PictureBox
{
Name = "pictureBox" + i,
Size = new Size(20, 20),
Location = new Point(i * 40, i * 40),
BorderStyle = BorderStyle.FixedSingle,
SizeMode = PictureBoxSizeMode.Zoom,
ImageLocation = "A.jpg"
};
pictureBoxList.Add(picture);
}
foreach (PictureBox p in pictureBoxList)
{
p.MouseDown += new MouseEventHandler(c_MouseDown);
p.MouseMove += new MouseEventHandler(c_MouseMove);
p.MouseUp += new MouseEventHandler(c_MouseUp);
pnlDisplayImage.Controls.Add(p);
pnlDisplayImage.Refresh();
}
}
void c_MouseDown(object sender, MouseEventArgs e)
{
Control c = sender as Control;
isDragging = true;
move = e.Location;
}
void c_MouseMove(object sender, MouseEventArgs e)
{
if (isDragging == true) {
Control c = sender as Control;
for (int i = 0; i < pictureBoxList.Count(); i++)
{
if (c.Equals(pictureBoxList[i]))
{
pictureBoxList[i].Left += e.X - move.X;
pictureBoxList[i].Top += e.Y - move.Y;
}
}
}
}
void c_MouseUp(object sender, MouseEventArgs e)
{
isDragging = false;
}
}

Try something like (it's custom control with overrides, but should be easy to convert to events):
private bool _isMoved = false; // true if move mode on
private Point _pointMove = new Point(0); // for moving
protected override void OnMouseDown(MouseEventArgs e)
{
// if left button pressed
if(e.Button == MouseButtons.Left)
{
_pointMove.X = e.X;
_pointMove.Y = e.Y;
_isMoved = true;
Cursor = Cursors.SizeAll;
Capture = true;
}
base.OnMouseDown (e);
}
protected override void OnMouseUp(MouseEventArgs e)
{
// if move mode on
if(_isMoved)
{
_isMoved = false;
Cursor = Cursors.Default;
Capture = false;
}
base.OnMouseUp (e);
}
protected override void OnMouseMove(MouseEventArgs e)
{
// if move mode on
if (_isMoved)
{
Left += e.X - _pointMove.X;
Top += e.Y - _pointMove.Y;
}
base.OnMouseMove (e);
}

WPF C# PreviewDrop/Drop event not fired ( With dragadorner)

I assume that previewdrop/drop events fired when it detect a drag target with an element as a drop target . In this case , my drop target is a textbox and my drag target is a label. Both of them are dynamically created from DB . I am using DragAdorner to clone the element that i am dragging , before implementing the DragAdorner , my DnD works well but after i use the dragadorner , it won't work . And i notice my previewdrop event is not firing when i try to debug .
Here are my codes :
tbox.Drop += new DragEventHandler(tbox_PreviewDrop); // text box , Drop Target
tbox.DragOver += new DragEventHandler(tbox_DragOver);
Label lbl = new Label(); // Label , Drag Target
lbl.Content = s;
lbl.Width = Double.NaN;
lbl.Height = 40;
lbl.FontSize = 19;
lbl.PreviewMouseDown += new MouseButtonEventHandler(lbl_MouseDown);
lbl.PreviewMouseMove += new MouseEventHandler(lbl_MouseMove);
lbl.PreviewGiveFeedback += new GiveFeedbackEventHandler(lbl_GiveFeedback);
private void lbl_MouseDown(object sender, MouseButtonEventArgs e)
{
startPoint = e.GetPosition(this);
// Mouse.OverrideCursor = Cursors.None;
}
private void lbl_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
// Mouse.OverrideCursor = Cursors.None;
var source = sender as UIElement;
Label lbl = sender as Label;
Point current = e.GetPosition(this);
Vector diff = startPoint - current;
if (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance)
{
adorner = new DragAdorner(lbl, e.GetPosition(lbl));
AdornerLayer.GetAdornerLayer(lbl).Add(adorner);
var dragData = new DataObject(this);
DragDrop.DoDragDrop(source, dragData, DragDropEffects.Copy);
AdornerLayer.GetAdornerLayer(lbl).Remove(adorner);
}
startPoint = current;
}
}
private void lbl_GiveFeedback(object sender, GiveFeedbackEventArgs e)
{
if (adorner != null)
{
Label lbl = sender as Label;
var pos = lbl.PointFromScreen(GetMousePosition());
adorner.UpdatePosition(pos);
e.Handled = true;
}
}
private void tbox_PreviewDrop(object sender, DragEventArgs e)
{
(sender as TextBox).Text = string.Empty; // Empty the textbox from previous answer.
(sender as TextBox).Background = Brushes.White;
e.Effects = DragDropEffects.Move;
e.Handled = true;
}
private void tbox_DragOver(object sender, DragEventArgs e)
{
e.Handled = true;
e.Effects = DragDropEffects.Move;
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool GetCursorPos(ref Win32Point pt);
[StructLayout(LayoutKind.Sequential)]
internal struct Win32Point
{
public Int32 X;
public Int32 Y;
};
public static Point GetMousePosition()
{
Win32Point w32Mouse = new Win32Point();
GetCursorPos(ref w32Mouse);
return new Point(w32Mouse.X, w32Mouse.Y);
}
private Point startPoint;
private DragAdorner adorner;
And the adorner class file :
public class DragAdorner : Adorner {
public DragAdorner(UIElement adornedElement, Point offset)
: base(adornedElement) {
this.offset = offset;
vbrush = new VisualBrush(AdornedElement);
//vbrush.Opacity = .7;
}
public void UpdatePosition(Point location) {
this.location = location;
this.InvalidateVisual();
}
protected override void OnRender(DrawingContext dc) {
var p = location;
p.Offset(-offset.X, -offset.Y);
dc.DrawRectangle(vbrush, null, new Rect(p, this.RenderSize));
}
private Brush vbrush;
private Point location;
private Point offset;
}
I seen http://www.adorkable.us/books/wpf_control_development.pdf ( page 103 ) but its way too complicated for me as i am a newbie .
It is because of my GiveFeedBack event that is in conflict with other events?

Since your DragAdorner is always under your cursor, it will be the object receiving the drop. If you set IsHitTestVisible = false; in the constructor for the Adorner, it should fix this.
Even though you haven't set AllowDrop on the Adorner, since it is under the cursor, it will intercept the drop attempt. But since it doesn't accept drop, it will just cancel it.
Update
The other issue is that you are setting the allowed effects in your drag operation to DragDropEffects.Copy, but in the DragOver and Drop handlers, you're trying to do a DragDropEffects.Move. This won't work, as those are not the same operation. These must match. If you want to enable both operations on drag, you can specify both with a bitwise or:
DragDrop.DoDragDrop(source, dragData, DragDropEffects.Copy | DragDropEffects.Move);
Update 2
If you want to drop anything other than a string onto a TextBox, you have to use the PreviewDrop and PreviewDragOver events. Otherwise, the TextBox's default handling will ignore anything else. So it would look like this:
tbox.PreviewDrop += new DragEventHandler(tbox_PreviewDrop);
tbox.PreviewDragOver += new DragEventHandler(tbox_DragOver);

Try setting background color for your label and see if it will work properly.