[.net] Preventing Graphics to update
Author
Is there a lock member or something for Graphics?
I am using GDI+ to draw multiple layers in an editor. The problem is that the editor keeps blinking in the areas with multiple layers (only the top layers blink) I certainly need a method to lock the Graphics object so it only updates after I finish drawing all the graphics.
After looking for in the code completion and MSDN I couldn't find an obvious name for that member, so I'd better ask here.
The alternative would be drawing everything to a bitmap and then just paint the bitmap to the graphics object but that might be less efficient
You can declare a control as double buffered in its constructor (you need to be developing a custom control):
Alternatively, as you suggested you can do the buffering yourself by drawing to a bitmap instead and then using DrawImage() to paint the bitmap onto your control.
this.Setstyle(Controlstyles.DoubleBuffered, true)Alternatively, as you suggested you can do the buffering yourself by drawing to a bitmap instead and then using DrawImage() to paint the bitmap onto your control.
Quote:Original post by Bob Janova
You can declare a control as double buffered in its constructor (you need to be developing a custom control):this.Setstyle(Controlstyles.DoubleBuffered, true)
Alternatively, as you suggested you can do the buffering yourself by drawing to a bitmap instead and then using DrawImage() to paint the bitmap onto your control.
Not entirely true. Using reflection you can set the style.
[C#]
try{ Type type = m_control.GetType(); BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Instance; MethodInfo method = type.GetMethod("Setstyle", flags); if (method != null) { object[] param = { Controlstyles.AllPaintingInWmPaint | Controlstyles.Opaque, true }; method.Invoke(m_control, param); }}catch{}
Author
Encapsulation is just an idea anyways.
It uses reflection and I think reflection needs special permissions.
But well Seems will use my own control cause there is no way to render a bitmap into another bitmap without using GetPixel / SetPixel Is there?
It uses reflection and I think reflection needs special permissions.
But well Seems will use my own control cause there is no way to render a bitmap into another bitmap without using GetPixel / SetPixel Is there?
I'm a little confused as to what you are trying to do here. It is certainly possible to copy one bitmap to another:
Bitmap layer1 = GetLayer(1);Bitmap target = new Bitmap(width, height);Graphics g = Graphics.FromImage(target);g.DrawImage(layer1, 0, 0);g.Dispose();
By developing a custom control, the "custom" portion of the control could be as simple as modifying the constructor to call Setstyle.
The remainder of the control can be untouched.
An excellent article on this is at http://pluralsight.com/wiki/default.aspx/Craig.FlickerFreeControlDrawing.
public class ControlDoubleBuffered : Control{ public ControlDoubleBuffered() { Setstyle(Controlstyles.OptimizedDoubleBuffer | Controlstyles.UserPaint | Controlstyles.Opaque | Controlstyles.AllPaintingInWmPaint, true); }}The remainder of the control can be untouched.
An excellent article on this is at http://pluralsight.com/wiki/default.aspx/Craig.FlickerFreeControlDrawing.
Author
Bob Janova I did not have information about that method to get graphics from image, mostly because I was browsing Image and bitmap members thanks a lot for pointing that out
Quote:Original post by Vexorian
Encapsulation is just an idea anyways.
It uses reflection and I think reflection needs special permissions.
But well Seems will use my own control cause there is no way to render a bitmap into another bitmap without using GetPixel / SetPixel Is there?
Right. It definately works, I use it within my game engine because I want the end-programmer to be able to set the control to any object that inherits from the base Control class. Otherwise I would have to inherit every possible control and set the style manually. Or inherit from Control and set the style and only allow end-programmers to inherit from my custom base control class. So reflection definately has pluses.
No problem :). It's in a bit of a weird place, that's for sure; it took me a while to find it the first time I tried to do some layering like stuff too!
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