Question

I am trying to draw some text with CoreGraphics. Unfortunately there is no method which returns the width of the text. I tried getting the width using this method:

private float GetTextWidth(CGContext context, string text)
    {
        float   startWidth, 
                endWidth,
                textWidth;
        startWidth = context.TextPosition.X;
        context.SetTextDrawingMode(CGTextDrawingMode.Invisible);
        context.ShowText(text);
        endWidth = context.TextPosition.X;
        textWidth = endWidth - startWidth;
        return textWidth;
    }

but if I want a multiline text I also need to take the font into consideration.
So I thought about using a UILable and get the values from it doing the following:

RectangleF lableRect = new RectangleF((float)rect.X, (float)rect.Y, (float)rect.Width, (float)rect.Height);
            UILabel lable = new UILabel(lableRect){
                Font = UIFont.FromName(font.Family.ToString(), (float)font.Size),
                Text = text,
            };
SizeF uiSize = lable.StringSize(lable.Text, lable.Font);

Although the height seems to be ok, the width is not correct. Any idea why?

Answer 1

Try NSString. It has various overloads like:

SizeF size = new NSString (s).StringSize (font, UIScreen.MainScreen.Bounds.Width, UILineBreakMode.TailTruncation);

If you want a UILabel to fit the contained string you can also just call UILabel.SizeToFit(). Or if you want to know the size of a string in a UILabel, use UILabel.StringSize()