How to use InvalidateRect+Application.DoEvents without slowing down application?
I want to draw rectangle on the desktop as I move mouse cursor. Old rectangle needs to be gone before drawing new one.
However InvalidateRect will occur after the new rectangle is drown so all rectangles are gone. So I had to add Application.DoEvents() to process InvalidateRect before draw new rectangle. But it slows down my application. Is there a better way to do this?
void mouseHook_MouseMove(object sender, MouseEventArgs e)
{
label1.Text = (Cursor.Position.X + " : " + Cursor.Position.Y);
if (start == true)
{
IntPtr desktopPtr = GetDC(IntPtr.Zero);
System.Drawing.Graphics g = System.Drawing.Graphics.FromHdc(desktopPtr);
Rectangle bb = new Rectangle(1, 1, 1, 1);
bb = DrawRec(Cursor.Position.X, Cursor.Position.Y, desktopPtr, g);//getting new rectangle to draw on the desktop, rectangle topleft position is fixed
Application.DoEvents();
g.DrawRectangle(new Pen(Color.Red, 1), bb);
ReleaseDC(this.Handle, desktopPtr);
g.Dispose();
}
}
The code works but it runs slow. In the google search I found I might be able to use print event and make all the drawing task in to list and process them one by one but I don't know how I can do that. I need sample codes.
c#
asked Jan 2 at 0:40
user1785594user1785594
8228
add a comment |
I want to draw rectangle on the desktop as I move mouse cursor. Old rectangle needs to be gone before drawing new one.
However InvalidateRect will occur after the new rectangle is drown so all rectangles are gone. So I had to add Application.DoEvents() to process InvalidateRect before draw new rectangle. But it slows down my application. Is there a better way to do this?
void mouseHook_MouseMove(object sender, MouseEventArgs e)
{
label1.Text = (Cursor.Position.X + " : " + Cursor.Position.Y);
if (start == true)
{
IntPtr desktopPtr = GetDC(IntPtr.Zero);
System.Drawing.Graphics g = System.Drawing.Graphics.FromHdc(desktopPtr);
Rectangle bb = new Rectangle(1, 1, 1, 1);
bb = DrawRec(Cursor.Position.X, Cursor.Position.Y, desktopPtr, g);//getting new rectangle to draw on the desktop, rectangle topleft position is fixed
Application.DoEvents();
g.DrawRectangle(new Pen(Color.Red, 1), bb);
ReleaseDC(this.Handle, desktopPtr);
g.Dispose();
}
}
The code works but it runs slow. In the google search I found I might be able to use print event and make all the drawing task in to list and process them one by one but I don't know how I can do that. I need sample codes.
c#
asked Jan 2 at 0:40
user1785594user1785594
8228
add a comment |
I want to draw rectangle on the desktop as I move mouse cursor. Old rectangle needs to be gone before drawing new one.
However InvalidateRect will occur after the new rectangle is drown so all rectangles are gone. So I had to add Application.DoEvents() to process InvalidateRect before draw new rectangle. But it slows down my application. Is there a better way to do this?
void mouseHook_MouseMove(object sender, MouseEventArgs e)
{
label1.Text = (Cursor.Position.X + " : " + Cursor.Position.Y);
if (start == true)
{
IntPtr desktopPtr = GetDC(IntPtr.Zero);
System.Drawing.Graphics g = System.Drawing.Graphics.FromHdc(desktopPtr);
Rectangle bb = new Rectangle(1, 1, 1, 1);
bb = DrawRec(Cursor.Position.X, Cursor.Position.Y, desktopPtr, g);//getting new rectangle to draw on the desktop, rectangle topleft position is fixed
Application.DoEvents();
g.DrawRectangle(new Pen(Color.Red, 1), bb);
ReleaseDC(this.Handle, desktopPtr);
g.Dispose();
}
}
The code works but it runs slow. In the google search I found I might be able to use print event and make all the drawing task in to list and process them one by one but I don't know how I can do that. I need sample codes.
c#
asked Jan 2 at 0:40
user1785594user1785594
8228
I want to draw rectangle on the desktop as I move mouse cursor. Old rectangle needs to be gone before drawing new one.
However InvalidateRect will occur after the new rectangle is drown so all rectangles are gone. So I had to add Application.DoEvents() to process InvalidateRect before draw new rectangle. But it slows down my application. Is there a better way to do this?
void mouseHook_MouseMove(object sender, MouseEventArgs e)
{
label1.Text = (Cursor.Position.X + " : " + Cursor.Position.Y);
if (start == true)
{
IntPtr desktopPtr = GetDC(IntPtr.Zero);
System.Drawing.Graphics g = System.Drawing.Graphics.FromHdc(desktopPtr);
Rectangle bb = new Rectangle(1, 1, 1, 1);
bb = DrawRec(Cursor.Position.X, Cursor.Position.Y, desktopPtr, g);//getting new rectangle to draw on the desktop, rectangle topleft position is fixed
Application.DoEvents();
g.DrawRectangle(new Pen(Color.Red, 1), bb);
ReleaseDC(this.Handle, desktopPtr);
g.Dispose();
}
}
The code works but it runs slow. In the google search I found I might be able to use print event and make all the drawing task in to list and process them one by one but I don't know how I can do that. I need sample codes.
c#
c#
asked Jan 2 at 0:40
user1785594user1785594
8228
asked Jan 2 at 0:40
user1785594user1785594
8228
asked Jan 2 at 0:40
user1785594user1785594
8228
asked Jan 2 at 0:40
user1785594user1785594
8228
asked Jan 2 at 0:40
user1785594user1785594
8228
8228
add a comment |
add a comment |
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