I have a WPF window with expandable panel (via Expander). The panel is on the left side of the window, and when expanded the window grows to fit the content.
By default, windows are anchored to the top-left, so my window grows to the right. I'd like the window to grow to the left.
I tried to do the following in the Window.SizeChanged event:
private void onWindowSizeChanged(object sender, SizeChangedEventArgs e)
{
Left -= (e.NewSize.Width - e.PreviousSize.Width)
}
and it works, but the growth is jerky, and I'd like to find a smoother solution.
I managed to overcome this using a simple solution: Hide & Show.
Here's the code:
protected override void OnRenderSizeChanged(SizeChangeInfo sizeInfo)
{
if (!sizeInfo.WidthChanged)
{
base.OnRenderSizeChanged(sizeInfo);
return;
}
Hide();
base.OnRenderSizeChanged(sizeInfo);
Left -= (sizeInfo.NewSize.Width - sizeInfo.PreviousSize.Width);
Show();
}
I replaced the event handler for Window.SizeChanged with this override of FrameworkElement.OnRenderSizeChanged.
I haven't tried to make a Window grow to the left like what you're requesting, but if all else fails, I would consider templating a button to look like the expander button. Then instead of trying to make your Window grow to the left, make a new Window grow to the left of your primary Window using Transforms.
UPDATE
Well, the poor rendering performance could be video card related, layout (overly complex) related, or both. I've got an idea that might do the trick for you. Jeff Prosise blogged about a magnifying glass in Silverlight that uses a WriteableBitmap to achieve the desired effect. I thought, "why not use a WriteableBitmap to create a screenshot of your layout to the right of the Expander, and cover up the other elements with it?". I think that if you do this and hide the underlying elements (so they don't get adjusted), rendering performance will be much improved.
I got Jeff's code to work in WPF with little modification.
http://www.wintellect.com/CS/blogs/jprosise/archive/2009/10/29/more-fun-with-silverlight-3-s-writeablebitmap.aspx
Solution 1
Try to use Window property: SizeToContent="width" this will scale your window to the size of your content and you can scale your content using animation and easing, this will make scaling of the window nice and smooth.
Solution 2
You could create a window which is bigger than it's content and make your background transparent. You still have to add background to some element.
Here is an example of how it may look like:
You may put your expander in a grid (where the column size can change) and then set the ExpandDirection property of your expander to left ?
Related
I have two GroupBoxes on the left side of one of my TabControls, call them GroupBox A (top left), and GroupBox B (bottom left). The GroupBoxes do not resize like I would hope.
Example:
When I resize the main form that has the TabControls with my mouse, or maximize it, or move it to a screen with lower resolution, GroupBox B keeps its width / height. This causes GroupBox B to draw over GroupBox A, kind of like a 'always on top' effect.
Desired:
Would like both GroupBoxes to resize according to one another / proporitionally and fit the area they are given.
Ideas?
A tableLayoutPanel can help with this.
Add a tableLayoutPanel and size it to fit your needs.
Anchor the table to Top, Bottom, Left, and Right
Put GroupBoxA into the upper left cell of the table
Put GroupBoxB into the lower right cell of the table
For both GroupBox size them accordingly and anchor them to all 4 sides.
Now they will grow and shrink proportionately with the app.
Additionally you can add more of your controls to the table. If you need a control to span multiple rows or columns use the RowSpan/ColumnSpan property.
If your GroupBox is inside another control like a tab or something, then do as below:
In my case I had a GroupBox inside a tab and I called the below methods in the InitializeComponent() method to force the Groupbox to adjust to the tab size.
this.groupBox4.ResumeLayout(false);
this.groupBox4.PerformLayout();
this.tabPage2.ResumeLayout(false);
this.tabPage2.PerformLayout();
And If you have multiple GroupBoxes, you need set the anchoring accordingly.
I faced a similar problem, I just had used the split container for both GroupBoxes, anchored the split container at top, bottom, left an right of my main form, and both GroupBoxes too, at top, bottom, left and right of their containers.
Slightly off topic from the original question, but my issue was that my MaximumSize field of my Group Box was not set, or was too small so I could not resize the height!
Altought the question is pretty old, someone might still find it useful...
I had the same problem and found a working solution -> instead of changing the width/height of the GroupBox, change its minimum width/height in the Form's resize method
edit: fixed typo
private void Form1_Resize(object sender, EventArgs e) {
groupBox1.MinimumSize = new Size(this.Width /2, this.Height);
}
I have an MdiClient derived from Form and I use the surface of this control for GDI+ drawing. I run into troubles implementing my own scrolling for this control. I set both AutoScroll and AutoSize properties to false and try to use form's own horizontal/vertical scrollbars instead of placing my own. Observed form's behavior is quite confusing. To begin with there are two properties (A) HScroll and (B) HorizontalScroll that also allows access to Visible attribute.
I ended up setting HorizontalScroll.Visible = true and leaving HScroll = false (same for vertical) but am curious why there are two of them. Documentation implies that both control visibility of horizontal scroll bar but they do not appear to access the same data. Besides, it looks like HScroll is being reset on every paint. At the moment I ignore existence of HScroll/VScroll. Is it OK for my application?
What is more critical for me is the ability control placement of the thumb on scroll bars. I set VerticalScroll attributes Minimum = 0, Maximum = 100, and Value = 50 but when form is displayed thumb is positioned at the start of scrollbar not in the middle. Why? Also when user clicks on horizontal scrollbar an event handler for horizontal scrolling is invoked but meanwhile form has already reset VerticalScroll.Value to 0 (without raising vertical scroll event). What is going on?
I probably don't understand how framework expects me to implement what I need. Can someone shed some light.
Credit goes to LarsTech who pointed me towards good solution. Setting large AutoScrollMinSize automatically does whatever needs to be done enabling and controlling form scrollbars. There is one potential trap to watch for. Be aware that programmatic attempts to set AutoScrollPosition will be ignored until form is shown. So if you want your form to open with scrollbars not in the default (0,0) position then place your code inside form_shown event handler.
Just set the AutoScrollMinSize to your desired canvas.
Quick example:
using System.Drawing;
using System.Drawing.Drawing2D;
private void Form1_Load(object sender, EventArgs e)
{
this.AutoScrollMinSize = new Size(1200, 1200);
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.Clear(SystemColors.Window);
using (Matrix mx = new Matrix(1, 0, 0, 1, this.AutoScrollPosition.X, this.AutoScrollPosition.Y))
{
e.Graphics.Transform = mx;
e.Graphics.FillEllipse(Brushes.Red, new Rectangle(250, 250, 100, 100));
}
}
See these links: Understanding Windows Forms AutoScroll and How to back-track the mouse to the virtual page.
I have a panel and on that I've a picturebox. There are around 20 labels that I've to show in the panel. I want the background of Label to be transparent ie the image in picturebox is shown and the label displays only the text.
Now since labels do not exhibit true transparency I made the labels child of picturebox
this.lbl1.Parent = pictureBox1;
This has solved my immediate problem but now when the form loads, all the labels take a while to become visible and do so one at a time. I'd appreciate if you guys can give some solution for this.
Thanks in advance
The standard cure for flicker is double-buffering. But that cannot solve this kind of flicker. It is a different kind, caused by having multiple windows overlapping each other. Each label is its own window. When the form needs to paint itself, it draws its background leaving holes for the child windows. Each child window then takes a turn drawing itself. And their child windows draw themselves next. Etcetera.
This becomes noticeable when one control takes a while to draw, no doubt your picture box. Especially when it displays a large image that needs to be resized. The holes for the child windows stay unpainted while the picture box draws. They have a white background, black when you use the form's TransparencyKey or Opacity property. This can contrast badly with the image in your picture box, that effect is perceived by the user as flicker.
One immediate cure is to not use controls so you don't pay for their window. A Label is very convenient but it is a massive waste of system resources to burn up a window just to display a string. You can simply implement the picture box' Paint event and draw the strings with TextRenderer.DrawText(). PictureBox has double-buffering turned on by default so the image as well as the text is drawn completely smoothly, no more flicker. The obvious disadvantage is that you lose the convenience of point-and-click, you have to write code.
There are other fixes possible. One of them is to prevent the picture box from leaving holes for the child windows. It will draw the entire image, the labels pop on top of them. That's still flicker but not nearly as noticeable. Add a new class to your project and paste this code:
using System;
using System.Windows.Forms;
internal class MyPictureBox : PictureBox {
protected override CreateParams CreateParams {
get {
var parms = base.CreateParams;
parms.Style &= ~0x02000000; // Turn off WS_CLIPCHILDREN
return parms;
}
}
}
Compile and drop the new picture box control from the top of the toolbox onto your form.
Yet another possible workaround is to make the form and all of its children double-buffered. This doesn't speed up the painting at all but all of the windows get rendered into a memory buffer, the result is blitted to the screen. You'll notice a delay but the window suddenly pops on the screen. This is called compositing. Winforms doesn't support this directly since it can have side-effects but it is easy to enable. Paste this code into your form class:
protected override CreateParams CreateParams {
get {
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x02000000; // Turn on WS_EX_COMPOSITED
return cp;
}
}
Supported by XP and later. Watch out for painting artifacts.
or you can ditch the labels and draw the text yourself:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
TextRenderer.DrawText(e.Graphics, "Label1", SystemFonts.DefaultFont,
new Point(10, 10), Color.Black, Color.Empty);
}
The label does not support transparency, you must create your own unique custom control, you can see these code examples.
http://www.codeproject.com/KB/dotnet/transparent_controls_net.aspx http://www.codeproject.com/KB/vb/uLabelX.aspx
Bye
I have stack panel with custom controls in it. I attach standard MouseDragElementBehavior to each item.
When I drag to the right the item moves underneath the other items.
What would be a viable solution to create better user experience - to show better visual cue - how the item moves and where is it going to be dropped.
After a bit of tinkering I realised that nothing can be dragged within stack panel to the right not being coverd by other elements .. unless you drag the very right item..
What I did to resolve it:
Created a visual cue (half transparent shape of a generic item to represnt it during the drag operation)
Made the cue invisible (width=0) and keep it always as the very last element of the stack panel children
Subscribed the stack panel to mouse left button up, down, move
Emulated drag/drop with code
Once the drag initated I turn the cue to visible and set its translate transform to the current mouse coordinates
Adjust translate transform on every mouse move event
On drop I hide the cue again and rearrange items in a way I want.
To stress again - whatever way you do - you have to manipulate with the last element in StackPanel.Children collection....
If the MouseDragElementBehavior doesn't work the way you need it to, you could always descend from the class and customize it to your needs. For example:
public class DragBehvaior : MouseDragElementBehavior
{
public DragBehvaior()
{
this.DragBegun += new MouseEventHandler(DragBehvaior_DragBegun);
}
void DragBehvaior_DragBegun(object sender, MouseEventArgs e)
{
var element = this.AssociatedObject as UIElement;
// Calculate the correct ZIndex here.
Canvas.SetZIndex(element, 100);
}
}
I am developing an kind of outlook calendar application where I need to make the appointment resizable from mouse.
My first try with a thumb did not work properly so I tried another way.
What I did is that:
1) on the botton of the appointmennt panel I added a rectangle to figure out the resize zone (the thumb). The appointment panel is put on a grid panel.
2) I intercept down event on the rectangle and send event to this code:
private Point startPoint;
private void OnResizeElementMouseDown(object sender, MouseButtonEventArgs e)
{
e.Handled = true;
this.MouseMove += new MouseEventHandler(ResizeEndElement_MouseMove);
this.MouseLeftButtonUp += new MouseButtonEventHandler(OnResizeElementMouseUp);
// some code to perform new height computation
Mouse.Capture(this);
}
where this is the appointment panel that own the thumb.
Decreasing height works well.
But increasing is more difficult. If I move the mouse very very slowly it's OK, if I speed it up a little bit it tends to leave out the appointment panel and then all MouseMove event are lost.
I thought Mouse.Capture() was propose to solve this kind of problem, but in fact not.
Does anybody know what is wrong in my code?
You should be using an actual Thumb control. Check out MSDN for help:
How to: Use a Thumb to Enable Dragging
you should use a thumb, but to play with mouse capture, override the protected override void OnLostMouseCapture(MouseEventArgs e) method, then you will know if you have lost the capture.