以编程方式截取特定区域的屏幕截图
以编程方式截取特定区域的屏幕截图
提问于 2012-01-02 23:58:01
正如您在我的代码中所看到的，我拍摄了一个屏幕截图并将其保存到相册中。
//for retina displays
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(self.view.bounds.size);
}
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);一开始，我使用webview.size而不是self.view.bounds.size，因为视图位于0/0，所以它工作正常。但是现在我将WebView居中，但图片是从给定大小的0/0开始的。
如何配置截图从指定大小的另一个location (例如300/150)开始？
还有没有别的方法可以给UIWebView拍照？
回答 2
Stack Overflow用户
发布于 2013-06-21 06:01:09
我已经接受并测试了@escrafford上面的答案，并让它工作得很好。我确实在UIView上将其设置为category方法的上下文中进行了测试，这样'grabRect‘就可以参数化。下面是返回UIImageView UIView类别代码：
/**
Takes a screenshot of a UIView at a specific point and size, as denoted by
the provided croppingRect parameter. Returns a UIImageView of this cropped
region.
CREDIT: This is based on @escrafford's answer at http://stackoverflow.com/a/15304222/535054
*/
- (UIImageView *)rp_screenshotImageViewWithCroppingRect:(CGRect)croppingRect {
// For dealing with Retina displays as well as non-Retina, we need to check
// the scale factor, if it is available. Note that we use the size of teh cropping Rect
// passed in, and not the size of the view we are taking a screenshot of.
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(croppingRect.size, YES, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(croppingRect.size);
}
// Create a graphics context and translate it the view we want to crop so
// that even in grabbing (0,0), that origin point now represents the actual
// cropping origin desired:
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, -croppingRect.origin.x, -croppingRect.origin.y);
[self.layer renderInContext:ctx];
// Retrieve a UIImage from the current image context:
UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Return the image in a UIImageView:
return [[UIImageView alloc] initWithImage:snapshotImage];
}Stack Overflow用户
发布于 2012-01-03 00:33:27
- (void)drawRect:(CGRect)rect {
UIGraphicsBeginImageContext(self.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
}您可以将此调用到您的视图:]
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原文链接：
https://stackoverflow.com/questions/8702834
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