Rotated row display - DataGridView.RowPostPaint
I want to display a long spinning row in the background of one of my rows in the DataGridView. However, this:
private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
{
if (e.RowIndex == 0)
{
...
//Draw the string
Graphics g = dataGridView1.CreateGraphics();
g.Clip = new Region(e.RowBounds);
g.RotateTransform(-45);
g.DrawString(printMe, font, brush, e.RowBounds, format);
}
}
doesn't work because the text is cut off before it is rotated.
I also tried drawing on Bitmap
, but there seems to be a problem with transparent bitmaps - the text comes out black.
Any ideas?
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I understood that. The problem was that bitmaps do not appear to have transparency even though you are using PixelFormat.Format32bppArgb
. Drawing a line made it draw on a black background, which is why it was so dark.
The solution was to copy a string from screen to bitmap, draw to bitmap and copy it back to screen.
g.CopyFromScreen(absolutePosition, Point.Empty, args.RowBounds.Size);
//Draw the rotated string here
args.Graphics.DrawImageUnscaledAndClipped(buffer, args.RowBounds);
Here is a complete list of links for reference:
private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs args)
{
if(args.RowIndex == 0)
{
Font font = new Font("Verdana", 11);
Brush brush = new SolidBrush(Color.FromArgb(70, Color.DarkGreen));
StringFormat format = new StringFormat
{
FormatFlags = StringFormatFlags.NoWrap | StringFormatFlags.NoClip,
Trimming = StringTrimming.None,
};
//Setup the string to be printed
string printMe = String.Join(" ", Enumerable.Repeat("RUNNING", 10).ToArray());
printMe = String.Join(Environment.NewLine, Enumerable.Repeat(printMe, 50).ToArray());
//Draw string onto a bitmap
Bitmap buffer = new Bitmap(args.RowBounds.Width, args.RowBounds.Height);
Graphics g = Graphics.FromImage(buffer);
Point absolutePosition = dataGridView1.PointToScreen(args.RowBounds.Location);
g.CopyFromScreen(absolutePosition, Point.Empty, args.RowBounds.Size);
g.RotateTransform(-45, MatrixOrder.Append);
g.TranslateTransform(-50, 0, MatrixOrder.Append); //So we don't see the corner of the rotated rectangle
g.DrawString(printMe, font, brush, args.RowBounds, format);
//Draw the bitmap onto the table
args.Graphics.DrawImageUnscaledAndClipped(buffer, args.RowBounds);
}
}
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