How can I center an image in a picturebox as I resize the form? What I have is a picturebox in a panel so if the image is larger than the picturebox, I can get scrollbars on the panel. But this doesn't work with the picturebox size mode "Center Image" and only works with "Auto Size".
This can easily be done with the SizeMode property
pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.CenterImage;
Don't use a PictureBox here, a Panel is already perfectly capable of displaying a centered image through its BackgroundImage property. All that's needed is to turn on its DoubleBuffered property to suppress flicker. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto your form, replacing the panel. Assign its BackgroundImage property with the Properties window or in your code.
using System;
using System.Drawing;
using System.Windows.Forms;
internal class PicturePanel : Panel {
public PicturePanel() {
this.DoubleBuffered = true;
this.AutoScroll = true;
this.BackgroundImageLayout = ImageLayout.Center;
}
public override Image BackgroundImage {
get { return base.BackgroundImage; }
set {
base.BackgroundImage = value;
if (value != null) this.AutoScrollMinSize = value.Size;
}
}
}
What's wrong with using Padding?
void picturebox_Paint(object sender, PaintEventArgs e)
{
int a = picturebox.Width - picturebox.Image.Width;
int b = picturebox.Height - picturebox.Image.Height;
Padding p = new System.Windows.Forms.Padding();
p.Left = a / 2;
p.Top = b / 2;
picturebox.Padding = p;
}
Related
After asking this: Prevent AutoScroll when contained Control gets focus I've found a way to have a scrollbar without the AutoScroll (using a derived class which can access the VScroll property). However - it's not in real-time. i.e. Only when the user is done scrolling does the Control actually get scrolled. (as opposed to a Panel with AutoScroll = true.) So how do I get it to scroll in real-time?
My code:
using System.Drawing;
using System.Windows.Forms;
namespace test
{
public partial class Form1 : Form
{
MyPanel panel = new MyPanel
{
//AutoScroll = true,
Size = new Size(200, 200),
Location = new Point(0, 30),
BackColor = Color.Green
};
Button b1 = new Button
{
Location = new Point(100, 100),
Size = new Size(50, 150),
BackColor = Color.Black
};
Button b2 = new Button();
public Form1()
{
InitializeComponent();
panel.Controls.Add(b1);
Controls.Add(panel);
Controls.Add(b2);
Shown += new System.EventHandler(Form1_Shown);
}
void Form1_Shown(object sender, System.EventArgs e)
{
panel.VerticalScroll.Visible = true;
panel.SetV();
}
}
class MyPanel : Panel
{
public void SetV() { VScroll = true; }
}
}
As in the comment:
You'll need to override the panel's OnScroll() method and call
SetDisplayRectLocation(0, -se.NewValue).
That's the answer to this question.
However, I've found that I can't have both scrollbars simultaneously. Or at least - I haven't found a way to do it.
I have a UserControl that contains a PictureBox and a Label. The Control loads three different images in PictureBox on different events (fore example onMouseEnter, OnMouseLeave). As the images can have different sizes, I neet to resize the pictureBox and
the control itself. Below is provided the control's OnPaint event but this does not work.
protected override void OnPaint(PaintEventArgs pe)
{
if (pictureBox.Image != null)
{
this.Width = this.pictureBox.Image.Size.Width;
this.Height = this.pictureBox.Image.Size.Height;
CutRoundedRectangle2(pictureBox, cornerRadius);
}
else
{
Bitmap DrawArea = new Bitmap(pictureBox.Size.Width, pictureBox.Size.Height);
Graphics g = Graphics.FromImage(DrawArea);
Pen mypen = new Pen(Color.Black);
pictureBox.Image = DrawArea;
System.Drawing.Pen pen = new Pen(new SolidBrush(this.ForeColor));
g.DrawRectangle(pen, 0, 0, this.Width-1, this.Height-1);
g.Dispose();
}
this.labelText.ocation = new Point((this.pictureBox.Width - this.labelText.Width) / 2,
(this.pictureBox.Height - this.labelText.Height) / 2);
base.OnPaint(pe);
}
The pictureBox SizeMode is set in control's constuctor:
this.pictureBox.SizeMode = PictureBoxSizeMode.AutoSize;
It was long time ago when I worked with WinForms last time, but ...
My first thought is: have you tried set value of parent control's AutoSize property to 'true' and AutoSizeMode to GrowAndShrink and call parent control's Refresh() method when new image is loaded to picture box?
#Alexey, the pictureBox resize event helped!
private void pictureBox_Resize(object sender, EventArgs e)
{
this.Width = this.pictureBox.Image.Size.Width;
this.Height = this.pictureBox.Image.Size.Height;
}
Is it possible to Draw any Form (without overridding the Paint method) in grayscale.
If I show a Form in a Modal() Dialog, I wan't do show its parent as grayscale.
I noticed this in the Visual Studio Extension Manager. If a progressbar is downloading a package, the underlying window is grayed out.
I am thinking of this:
private void Button1_Click(object sender, EventArgs e)
{
using (var dialog = new Form2())
{
SetGrayscale(this, true);
dialog.ShowDialog();
SetGrayscale(this, false);
}
}
Update
Just setting Form.Enabled = false; is not what I intended. That does not look as good as a grayscale representation of my form.
I think the compiz window decorator for Linux did this with apps that are unresponsive.
As has already been said the way to do this is to overlay another control / form on top of your existing form and have it render a grayscale version of this on top, you could either do this using an additional form placed exactly over the original form, or using something like a Panel positioned on top of all other controls.
Here is a working example of how you might do this when placing another form exactly over the client area of the first. How to use it
using (Grayscale(this))
{
MessageBox.Show("Test");
}
Implementation
public static Form Grayscale(Form tocover)
{
var frm = new Form
{
FormBorderStyle = FormBorderStyle.None,
ControlBox = false,
ShowInTaskbar = false,
StartPosition = FormStartPosition.Manual,
AutoScaleMode = AutoScaleMode.None,
Location = tocover.PointToScreen(tocover.ClientRectangle.Location),
Size = tocover.ClientSize
};
frm.Paint += (sender, args) =>
{
var bmp = GetFormImageWithoutBorders(tocover);
bmp = ConvertToGrayscale(bmp);
args.Graphics.DrawImage(bmp, args.ClipRectangle.Location);
};
frm.Show(tocover);
return frm;
}
private static Bitmap ConvertToGrayscale(Bitmap source)
{
var bm = new Bitmap(source.Width, source.Height);
for (int y = 0; y < bm.Height; y++)
{
for (int x = 0; x < bm.Width; x++)
{
Color c = source.GetPixel(x, y);
var luma = (int)(c.R * 0.3 + c.G * 0.59 + c.B * 0.11);
bm.SetPixel(x, y, Color.FromArgb(luma, luma, luma));
}
}
return bm;
}
private static Bitmap GetControlImage(Control ctl)
{
var bm = new Bitmap(ctl.Width, ctl.Height);
ctl.DrawToBitmap(bm, new Rectangle(0, 0, ctl.Width, ctl.Height));
return bm;
}
private static Bitmap GetFormImageWithoutBorders(Form frm)
{
// Get the form's whole image.
using (Bitmap wholeForm = GetControlImage(frm))
{
// See how far the form's upper left corner is
// from the upper left corner of its client area.
Point origin = frm.PointToScreen(new Point(0, 0));
int dx = origin.X - frm.Left;
int dy = origin.Y - frm.Top;
// Copy the client area into a new Bitmap.
int wid = frm.ClientSize.Width;
int hgt = frm.ClientSize.Height;
var bm = new Bitmap(wid, hgt);
using (Graphics gr = Graphics.FromImage(bm))
{
gr.DrawImage(wholeForm, 0, 0,
new Rectangle(dx, dy, wid, hgt),
GraphicsUnit.Pixel);
}
return bm;
}
}
Note that:
The implementation of Paint is fairly poor - really it should use double buffering so that the grayscale image is pre-rendered to a buffered graphics context so the Paint method just needs to paint the pre-drawn buffer contents. See Custom Drawing Controls in C# – Manual Double Buffering
ConvertToGrayscale is a tad on the slow side, but can probably be sped up
Things will go wrong if someone manages to move the original form for any reason
The image is static, if the base control gets redrawn then ideally the top form should redraw too. I'm not sure how best to detect when a portion of another form has been invalidated.
If I find the time I'll try and fix some of those problems, but the above at least gives you the general idea.
Note that in WPF this would be a lot easier.
Sources:
How to convert a colour image to grayscale
Get the image of a control or form, or a form's client area in C#
I don't think there is a way to do it directly - I think all forms are rendered with sRGB.
A hacky way could be to overlay the form with a copy of it as an image (this is simple to do with Control.DrawToBitMap) and then pass it through a simple GDI matrix to desaturate https://web.archive.org/web/20141230145627/http://bobpowell.net/grayscale.aspx.
Try something like this which would work for most simple controls (you would need to recurse into containers to switch all controls correctly).
private void button1_Click(object sender, EventArgs e)
{
using (var dialog = new Form())
{
Dictionary<Control, Tuple<Color, Color>> oldcolors = new Dictionary<Control, Tuple<Color, Color>>();
foreach (Control ctl in this.Controls)
{
oldcolors.Add(ctl, Tuple.Create(ctl.BackColor, ctl.ForeColor));
// get rough avg intensity of color
int bg = (ctl.BackColor.R + ctl.BackColor.G + ctl.BackColor.B) / 3;
int fg = (ctl.ForeColor.R + ctl.ForeColor.G + ctl.ForeColor.B) / 3;
ctl.BackColor = Color.FromArgb(bg, bg, bg);
ctl.ForeColor = Color.FromArgb(fg, fg, fg);
}
dialog.ShowDialog();
foreach (Control ctl in this.Controls)
{
ctl.BackColor = oldcolors[ctl].Item1;
ctl.ForeColor = oldcolors[ctl].Item2;
}
}
}
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.
I'm creating a Windows Forms application. How do I capture the size of the windows form?
Currently I have something that looks like this in my code:
PictureBox display = new PictureBox();
display.Width = 360;
display.Height = 290;
this.Controls.Add(display);
display.Image = bmp;
However, the size of my display is hard-coded to a specific value.
I know that if I want to draw a square that re-sizes I can use something like this:
private Rectangle PlotArea;
private int offset = 30;
protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
//// Calculate the location and size of the plot area
//// within which we want to draw the graphics:
Rectangle ChartArea = ClientRectangle;
PlotArea = new Rectangle(ChartArea.Location, ChartArea.Size);
PlotArea.Inflate(-offset, -offset);
Draw PlotArea:
g.DrawRectangle(Pens.Black, PlotArea);
}
Is there a way for me to use method one and grab the size of the form for Height and Width?
I've tried the following code, but it doesn't work...
PictureBox display = new PictureBox();
display.Width = ClientRectangle.Y;
display.Height = ClientRectangle.X;
this.Controls.Add(display);
display.Image = bmp;
For Getting the size of a Windows Form:
int formHeight = this.Height;
int formWidth = this.Width;
PictureBox display = new PictureBox();
display.Width = ClientRectangle.Width;
display.Height = ClientRectangle.Height;
this.Controls.Add(display);
display.Image = bmp;
When you resize the window:
private void Form1_Resize(object sender, System.EventArgs e)
{
Control control = (Control)sender;
// set the PictureBox width and heigh here using control.Size.Height
// and control.Size.Width
}
You want to set Dock = DockStyle.Fill to dock the control to fill its parent.
Set it to ClientRectangle.Width.