問題描述
畫面區域的選擇 (Selection of screen area)
I am trying to make a in‑app screenshot which I have the following codes.
How can to select the area for the screenshot? e.g. I want to get rid of the UInavigation bar and the bottom tabbar. What code should I add?
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData * imageData = UIImageJPEGRepresentation(image, 1.0);
if ( [MFMailComposeViewController canSendMail] ) {
MFMailComposeViewController * mailComposer = [[MFMailComposeViewController alloc] init];
mailComposer.mailComposeDelegate = self;
[mailComposer addAttachmentData:imageData mimeType:@"image/jpeg" fileName:@"attachment.jpg"];
‑‑‑‑‑
參考解法
方法 1:
You can identify the rect of the region and crop that part of the image to get the image you need.
....
/* Identify the region that needs to be cropped */
CGRect navigationBarFrame = self.navigationController.navigationBar.frame;
CGRect tabBarFrame = self.tabBarController.tabBar.frame;
CGRect screenshotFrame;
screenshotFrame.origin.x = 0;
screenshotFrame.origin.y = navigationBarFrame.size.height;
screenshotFrame.size.width = navigationBarFrame.size.width;
screenshotFrame.size.height = tabBarFrame.origin.y ‑ screenshotFrame.origin.y;
/* Crop the region */
CGImageRef screenshotRef = CGImageCreateWithImageInRect(image, screenshotFrame);
UIImage * screenshot = [[(UIImage *)screenshotRef retain] autorelease];
CGImageRelease(screenshotRef);
/* Convert to data and send */
NSData * screenshotData = UIImageJPEGRepresentation(screenshot, 1.0);
if ( [MFMailComposeViewController canSendMail] ) {
....
[mailComposer addAttachmentData:screenshotData
mimeType:@"image/jpeg"
fileName:@"attachment.jpg"];
....
}
If you are manually using a navigation bar and/or tab bar then replace the self.navigationController.navigationBar and self.tabBarController.tabBar appropriately.
(by Clarence、Deepak Danduprolu)