创建了一个UIView，并在UIView中不断添加和删除小的snow.png以模拟下雪的效果。然后我想将屏幕捕获为图像。UIGraphicsBeginImageContext(self.uiviewPreview.bounds.size);[self.uiviewPreview.layerrenderInContext:UIGraphicsGetCurrentContext()];UIImage*viewImage=UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();UIImageWriteTo