iphone - UIView 绘制时的背景色

Question

Objective-C 或 C# .Net 答案很好

我有一个 UIView，我在其中绘制文本。背景是黑色。如何使其白色或透明？

    public override void Draw(RectangleF rect)
    {   
        using (var context = UIGraphics.GetCurrentContext())
        {
            context.ScaleCTM(1f,-1f);
            context.SetFillColor(Settings.ColorButtonText.CGColor);
            context.SetTextDrawingMode(CGTextDrawingMode.Fill);
            context.SelectFont("HelveticaNeue-Bold",20f, CGTextEncoding.MacRoman);
            context.ShowTextAtPoint(5,-25,_title);
        }
    }

编辑:我的 Monotouch.Dialog 自定义部分的解决方案

public class BigBlueSectionHeaderView : UIView
{
    private readonly string _title;

    public BigBlueSectionHeaderView(string title): base(new RectangleF(0,0,320,35))
    {
        _title = title;
    }

    public override void Draw(RectangleF rect)
    {   
        using (var context = UIGraphics.GetCurrentContext())
        {
            context.SetFillColorWithColor(UIColor.White.CGColor);
            context.FillRect(new RectangleF(10, 0, 320, 35));
            context.ScaleCTM(1f,-1f);
            context.SetFillColor(Settings.ColorButtonText.CGColor);
            context.SetTextDrawingMode(CGTextDrawingMode.Fill);
            context.SelectFont("HelveticaNeue-Bold",20f, CGTextEncoding.MacRoman);
            context.ShowTextAtPoint(5,-25,_title);

        }
    }
}

Answer 1

您可以使用以下方法清除背景:

CGContextClearRect(context, rect);

或设置为白色:

CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillRect(context, rect);