我正在拍摄一些UIButtons的截图,这些UIButtons是500宽度和500高度的圆圈。由于屏幕截图只能以方形形式制作,而且我没有使用此代码的图像周围的白色角落:
UIGraphicsBeginImageContext(self.Button3.layer.bounds.size);
[self.Button3.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage* image2 = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData* data = UIImagePNGRepresentation(image);
[data writeToFile:BusinessCardPath atomically:YES];
这很完美,它只给我一张没有白角的圆圈的照片。但是它可以被放大,因为它将丢失像素,并且它不包括在镜头中所有元素,例如UILabel上方的UILabel,而不是UIButton的子视图。
如果我使用此代码:
CGSize imageSize = CGSizeMake(310, 310);
UIGraphicsBeginImageContext(self.Button3.layer.bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
/*CGContextTranslateCTM(context, -5, -50);*/
// Iterate over every window from back to front
for (UIWindow *window in [[UIApplication sharedApplication] windows])
{
if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
{
// -renderInContext: renders in the coordinate space of the layer,
// so we must first apply the layer's geometry to the graphics context
CGContextSaveGState(context);
// Center the context around the window's anchor point
CGContextTranslateCTM(context, [window center].x, [window center].y);
// Apply the window's transform about the anchor point
CGContextConcatCTM(context, [window transform]);
// Offset by the portion of the bounds left of and above the anchor point
CGContextTranslateCTM(context,
-[window bounds].size.width * [[window layer] anchorPoint].x,
-[window bounds].size.height * [[window layer] anchorPoint].y);
// Render the layer hierarchy to the current context
[[window layer] renderInContext:context];
// Restore the context
CGContextRestoreGState(context);
}
}
// Retrieve the screenshot image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
......我得到了相反的效果。上面的元素包含在屏幕截图中,高分辨率,但图像周围的白色角落。
答案 0 :(得分:2)
您可以使用CAShapeLayer屏蔽图像的某些部分。 .path属性用于定义将呈现的区域。
UIImageView *myImageView = [UIImageView alloc] init];
myImageView.image = [UIImage imageNamed:@"anImage.gif"];
[myImageView setClipsToBounds:YES];
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:myImageView.bounds byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(48, 48)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = myImageView.bounds;
maskLayer.path = maskPath.CGPath;
myImageView.layer.mask = maskLayer;
那应该给你一个圆形图像。您可能需要使用半径。