Monotouch Draw line on UIImage
Using开发者_C百科 Monotouch, how would I draw a simple line onto the image in a UIImage that is currently being display?
Simple example is of course fine.
Obj-C answer is ok too.
Assuming you have a custom UIImageView with an image set on its Image property, place this method in it:
private void DrawLineOnImage()
{
UIGraphics.BeginImageContext(this.Image.Size);
using (CGContext cont = UIGraphics.GetCurrentContext())
{
cont.TranslateCTM(0f, this.Image.Size.Height);
cont.ScaleCTM(1.0f, -1.0f);
cont.DrawImage(new RectangleF(0f,0f,this.Image.Size.Width, this.Image.Size.Height), this.Image.CGImage);
cont.ScaleCTM(1.0f, -1.0f);
cont.TranslateCTM(0f, -this.Image.Size.Height);
using (CGPath path = new CGPath())
{
cont.SetLineWidth(3);
cont.SetRGBStrokeColor(255, 0, 0, 1);
path.AddLines(new PointF[] {
new PointF(10, 10),
new PointF(100, 100) });
path.CloseSubpath();
cont.AddPath(path);
cont.DrawPath(CGPathDrawingMode.FillStroke);
this.Image = UIGraphics.GetImageFromCurrentImageContext();
}//end using path
}//end using cont
UIGraphics.EndImageContext();
}//end void DrawLineOnImage
This draws a red line on the image itself.
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