iOS 截屏，裁剪，截圖，高清方法 模糊

+(UIImage*)captureScreen:(UIView*)viewToCapture
{
    UIGraphicsBeginImageContextWithOptions(viewToCapture.bounds.size, NO, 0.0);
    [viewToCapture.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return viewImage;

}

 UIGraphicsBeginImageContext(viewToCapture.bounds.size);//模糊
    UIGraphicsBeginImageContextWithOptions(viewToCapture.bounds.size, NO, 0.0);//原圖