[英]How is it correct for display json object in .xaml file using xamarin c# iOS
[英]How to get correct value of pixel on touch in ios xamarin c#
您好,我试图在Xamarin C#中获得触摸时像素的颜色,但是有时我得到的值是错误的,我得到R = 255,G = 0,B = 0,A = 0我的代码有什么问题?
private UIColor ColorOfPoint(CGPoint point)
{
byte[] pixel = {0,0,0,0};
using(CGColorSpace oColorSpace = CGColorSpace.CreateDeviceRGB())
using(CGBitmapContext oContext = new CGBitmapContext(pixel,
1, 1, 8, 4, oColorSpace, CGBitmapFlags.PremultipliedLast & CGBitmapFlags.AlphaInfoMask))
{
oContext.TranslateCTM(-point.X,-point.Y);
img.Layer.RenderInContext(oContext);
oContext.Dispose();
oColorSpace.Dispose();
}
UIColor color = new UIColor(pixel[0]/255,pixel[1]/255,pixel[2]/255,pixel[3]/255);
return color;
}
使用UIColor.FromRGBA
代替new UIColor(....)
这是我的方法:
byte[] alphaPixel = { 0, 0, 0, 0 };
protected UIColor GetColorAtTouchPoint(CGPoint point)
{
var colorSpace = CGColorSpace.CreateDeviceRGB();
var bitmapContext = new CGBitmapContext(alphaPixel, 1, 1, 8, 4, colorSpace, CGBitmapFlags.PremultipliedLast);
bitmapContext.TranslateCTM(-point.X, -point.Y);
view.Layer.RenderInContext(bitmapContext);
return UIColor.FromRGBA(alphaPixel[0], alphaPixel[1], alphaPixel[2], alphaPixel[3]);
}
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