CGBitmapContext 中没有带有 function “ShowTextAtPoint”的德语变音符号

Question

we have a problem displaying text with german umlaute with the function ShowTextAtPoint in CGBitmapContext . The umlaute characters are not displayed.

We tried to convert Code from XCode:

CGContextSelectFont(MyBitmapContext, FontName, 24, kCGEncodingMacRoman);
CGContextShowTextAtPoint(MyBitmapContext, x, y, [caption cStringUsingEncoding:    
NSMacOSRomanStringEncoding], [caption length]);

to MonoTouch:

MyBitmapContext.SelectFont(FontName, 24, CGTextEncoding.MacRoman);
MyBitmapContext.ShowTextAtPoint(x, x, caption , caption.Length);

Thanks a lot for any help.

Frank

Answer 1

The problem is that CoreGraphics APIs for CGContext do not support rendering UTF8 code, it is limited to the text encoding in MacRoman (as you showed in your sample).

The fix is to use the UIKit functions instead, to do this, you can change your code to be like this:

UIGraphics.PushContext (mBmpContext);
mBmpContext.SetRGBFillColor(1f,1f,1f,1f);
var font = UIFont.FromName ("Arial", 30);
using (var nsstr = new NSString ("äöü ÜÖÄ")){
    nsstr.DrawString (new PointF (10, 400), font);
}
UIGraphics.PopContext ()