I am working on a simple Windows Forms application which consists of a Panel where I draw graphics with Graphic. Let's say, my panel is now of size 300x300 but the content inside is 500x500. Obviously, I need to add scrollbars to the Panel.
My code so far:
public CircuitControl()
{
// Initialize empty list of circuit objects
CircuitObjects = new List<CircuitObject>();
drawingAreaPanel.AutoScroll = true;
drawingAreaPanel.VerticalScroll.Enabled = true;
drawingAreaPanel.VerticalScroll.Visible = true;
drawingAreaPanel.HorizontalScroll.Enabled = true;
drawingAreaPanel.MaximumSize = new Size(300, 300);
drawingAreaPanel.Size = new Size(600, 600);
}
But none of these codes create actually a scroll bar. My question is: Where and how do I set the size of the Panel where I actually drew? I think this is the part which is missing. Thanks.
The scrollbars won't show up until there's actually something in the Panel that you can't see all of.
Try placing a larger control, such as a PictureBox, inside the Panel, and setting the PictureBox's initial size as larger than the Panel.
Just add:
drawingAreaPanel.AutoScroll = true;
And it will be done automatically.
€dit: Don't forget to set the anchors in order to get the scrollbars.
A clean and simple approach is to set AutoScrollMinSize. This shows the scrollbars (or just one if you leave the other value at 0).
Now drawing through the graphics object will not be scrolled automatically.
This can be easily achieved with a transformation matrix, which is set before painting and translates the drawing by the scroll offset.
A pretty example: (this flickers of course without further optimizations)
private void button1_Click(object sender, EventArgs e)
{
using(Form frm = new Form())
{
Panel pnl = new Panel();
pnl.Paint += delegate (Object snd, PaintEventArgs e2) {
Matrix mtx = new Matrix();
mtx.Translate(pnl.AutoScrollPosition.X, pnl.AutoScrollPosition.Y);
e2.Graphics.Transform = mtx;
e2.Graphics.Clear(Color.Black);
for(int i=0; i <= 125; i++)
for(int j=0; j <= 125; j++)
using(Brush b = new SolidBrush(Color.FromArgb(255, 255-i*2, j*2, (i*j) % 255)))
e2.Graphics.FillRectangle(b, new Rectangle(5+j*20, 5+i*20, 20, 20));
};
pnl.AutoScrollMinSize = new Size(126*20+10, 126*20+10);
pnl.Dock = DockStyle.Fill;
frm.Controls.Add(pnl);
frm.Padding = new Padding(25);
frm.ShowDialog(this);
}
}
Related
I use multiple panels and draw graphics on them.
Sometimes I need to add some changes to the graphics.
When I clear the panel and redraw everything inside - it works, but causes a flickering effect because all elements actually disappear and are created again.
Here is an example:
private void drawStatus() {
Panel Panel1 = new Panel();
Panel1.Width = 100;
Panel1.Height = 100;
Panel1.Location = new System.Drawing.Point(0, 0);
Panel1.Visible = true;
Panel1.Paint += new PaintEventHandler(Panel1Paint);
panelDashboard.Controls.Add(Panel1);
}
private void Panel1Paint(object sender, PaintEventArgs e) {
var g = e.Graphics;
Pen PenGray = new Pen(Color.Gray, 1F);
g.DrawRectangle(PenGray, SharedData.X, SharedData.Y, SharedData.W, SharedData.H);
PenGray.Dispose();
g.Dispose();
}
My thoughts are that I should fire PaintEventHandler again.
Panel1.Refresh() works for me, handler fires again, but it clears all panel content.
The question is, is it possible to fire the PaintEventHandler again without clearing the existing contents of the panel?
Or maybe there is another way to draw on the panel again.
I'm trying to add panel to already existing panel with name Tablica
but im doing it wrong im increasing the global variable each time i add the a panel so the new added panel has different Y location and this makes my panels not overlapping eachother.
But now i want to use a different approach so that i dont add them with fixed X,Y location and instead i somehow dock them on top and each new panel addded stays at the top of the parent panel so in other words the last panel added when the button is clicked stays on top of the Tablica panel
This is the code i use now which works except that the last panel is added at the bottom of the panel:
int TabliciLocation = 30; //global variable
private void OK_Click(object sender, EventArgs e)
{
Panel newPanel = new Panel();
newPanel.Size = new System.Drawing.Size(1200, 52);
newPanel.Location = new System.Drawing.Point(16, TabliciLocation);
Tablica.Controls.Add(newPanel);
TabliciLocation += 60;
}
So the new approach has to be something like this :
private void OK_Click(object sender, EventArgs e)
{
Panel newPanel = new Panel();
newPanel.Size = new System.Drawing.Size(1200, 52);
newPanel.Dock = DockStyle.Top; // if this can help
Tablica.Controls.Add(newPanel);
}
The FlowLayoutPanel was made for this.
Here is an example; I use different BackColors to show how each new Panel pushes the previous ones down:
Random R = new Random();
private void button1_Click(object sender, EventArgs e)
{
Panel p = new Panel();
p.Name = "panel" + (flowLayoutPanel1.Controls.Count + 1);
p.BackColor = Color.FromArgb(123, R.Next(222), R.Next(222));
p.Size = new Size(flowLayoutPanel1.ClientSize.Width, 50);
flowLayoutPanel1.Controls.Add(p);
flowLayoutPanel1.Controls.SetChildIndex(p, 0); // this moves the new one to the top!
// this is just for fun:
p.Paint += (ss, ee) => {ee.Graphics.DrawString(p.Name, Font, Brushes.White, 22, 11);};
flowLayoutPanel1.Invalidate();
}
I have a winform that starts out with a sizable border around it. On the form is a button which, when pressed, changes the form to border style none.
The problem is that then the inner part of the form moves up and to the left slightly. I want to make it that, no matter what border is used, the "inner" part of the form will always stay in the same spot (note: but I do still want the form to be moved around when it has a movable border selected)
Thanks.
The Borderless form moves up and slightly left because thats the location that the form currently has,you need to count for the border.To achieve the result you are after you need to reassign the location property and to do that you need to account for the client size and the whole size(with border),the code i think is simple and it will be self-explanatory i believe:
private void button1_Click(object sender, EventArgs e)
{
var X = (this.Size.Width - this.ClientRectangle.Width) / 2;
var Y = (this.Size.Height - this.ClientRectangle.Height) - X;
Point p = new Point(Location.X + X, Location.Y + Y);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.Location = p;
}
Another option is to set the padding on the parent that contains the panel with the border. E.g.
public class Form10 : Form {
Button btn = new Button { Text = "Button", Location = new Point(100, 100) };
Panel border = new Panel { Dock = DockStyle.Fill, BorderStyle = BorderStyle.Fixed3D };
public Form10() {
Controls.Add(border);
border.Controls.Add(btn);
btn.Click += delegate {
if (border.BorderStyle == BorderStyle.Fixed3D) {
border.BorderStyle = BorderStyle.None;
border.Parent.Padding = new Padding(2);
}
else {
border.BorderStyle = BorderStyle.Fixed3D;
border.Parent.Padding = new Padding(0);
}
};
}
}
I create a scrolling text with DrawString.
It works, but the text remains under the form elements. I would like the text to pass over.
The code:
int x = 0;
string texto = "prova prova";
int tam = 15;
private void timer_Tick_1(object sender, EventArgs e)
{
Graphics gra = this.CreateGraphics();
gra.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
gra.DrawString(texto, new Font("Times New Roman", tam), new SolidBrush(Color.CornflowerBlue),x, 70);
gra.Dispose();
x += 6;
if (x >= this.Width)
x = texto.Length * tam * -1;
}
This is by design, a Graphics object can only paint to the area it was created for.
If you want the text to appear in front of all other elements on the Form, you have to create a custom control which does the drawing.
Add an instance of this control to the Form and use the BringToFront method to position it on top of each other contained elements in the Form.
I'm developing a WinForms application and can't figure out how to resolve an issue.
I need to show an image in a Form. Because the image can be arbitrarily large, I need scrollbars on the picturebox containing the image so the user can see it entirely.
Googling around I found out the best way to achieve this is to add the PictureBox as a Child Control of a Panel, and making the Panel autosizable and autoscrollable.
I did that programatically since using the designer I was unable to insert the picturebox as a child control of the panel.
The problem I'm now facing is that I can't seem to be able to center and scroll the picturebox at the same time.
If I put the anchor of the picturebox to top,left,bottom,right, the scrollbars are not shown and the image displayed is strange, if I put back the anchor to only top-left, the image is not centered.
Is there any way to do both at the same time?
Here's the code for my Panel and Picturebox:
this.panelCapturedImage = new System.Windows.Forms.Panel();
this.panelCapturedImage.SuspendLayout();
this.panelCapturedImage.AutoScroll = true;
this.panelCapturedImage.AutoSize = true;
this.panelCapturedImage.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowAndShrink;
this.panelCapturedImage.Controls.Add(this.pictureBoxCapturedImage);
this.panelCapturedImage.Location = new System.Drawing.Point(0, 49);
this.panelCapturedImage.Name = "panelCapturedImage";
this.panelCapturedImage.Size = new System.Drawing.Size(3, 3);
this.panelCapturedImage.TabIndex = 4;
this.pictureBoxCapturedImage.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
this.pictureBoxCapturedImage.Location = new System.Drawing.Point(0, 0);
this.pictureBoxCapturedImage.Name = "pictureBoxCapturedImage";
this.pictureBoxCapturedImage.Size = new System.Drawing.Size(0, 0);
this.pictureBoxCapturedImage.SizeMode = System.Windows.Forms.PictureBoxSizeMode.CenterImage;
this.pictureBoxCapturedImage.TabIndex = 0;
this.pictureBoxCapturedImage.TabStop = false;
this.panelCapturedImage.Controls.Add(this.pictureBoxCapturedImage);
And here's where I set the image:
public Image CapturedImage
{
set
{
pictureBoxCapturedImage.Image = value;
pictureBoxCapturedImage.Size = value.Size;
}
}
For the PictureBox, set SizeMode = AutoSize, Anchor it Top, Left, and set its Location to 0, 0.
Set Panel.AutSize to False and Panel.AutoScroll to True.
When you set the PictureBox.Image property, it will auto-size to the size of the image. You can then use that size to set the panel's AutoScrollPosition property:
public Image CapturedImage
{
set
{
pictureBoxCapturedImage.Image = value;
panelCapturedImage.AutoScrollPosition =
new Point {
X = (pictureBoxCapturedImage.Width - panelCapturedImage.Width) / 2,
Y = (pictureBoxCapturedImage.Height - panelCapturedImage.Height) / 2
};
}
}
If the image is smaller then then panel's size, it will remain in the upper left corner. If you want it centered within the panel, you'll have to add logic to set its Location appropriately.
Based on earlier answers I was able to create this full example:
private void testShowPictureBox()
{
/* format form */
Form frmShowPic = new Form();
frmShowPic.Width = 234;
frmShowPic.Height = 332;
frmShowPic.MinimizeBox = false;
frmShowPic.MaximizeBox = false;
frmShowPic.ShowIcon = false;
frmShowPic.StartPosition = FormStartPosition.CenterScreen;
frmShowPic.Text = "Show Picture";
/* add panel */
Panel panPic = new Panel();
panPic.AutoSize = false;
panPic.AutoScroll = true;
panPic.Dock = DockStyle.Fill;
/* add picture box */
PictureBox pbPic = new PictureBox();
pbPic.SizeMode = PictureBoxSizeMode.AutoSize;
pbPic.Location = new Point(0, 0);
panPic.Controls.Add(pbPic);
frmShowPic.Controls.Add(panPic);
/* define image */
pbPic.ImageLocation = #"c:\temp\pic.png";
frmShowPic.ShowDialog();
}
The picturebox has to be set to autosize. anchored at the center (or a border).
You could manage all of this in the designer, don't undertand your problem with that.
The panel has to be set to autoscroll to true.