iOS中的几种截图方法

截取本区域(self.view):
UIGraphicsBeginImageContext(CGSizeMake(self.view.frame.size.width, self.view.frame.size.height));
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

全屏截图:
UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];
    UIGraphicsBeginImageContext(screenWindow.frame.size);
    [screenWindow.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

以上2种方法真机和模拟器都可以运行.在photo.app里可以看到照片

苹果最新开放的接口函数(全屏截图),已经有人试过了,不会reject:
CGImageRef UIGetScreenImage(); 
CGImageRef img = UIGetScreenImage();
UIImage* scImage=[UIImage imageWithCGImage:img];
UIImageWriteToSavedPhotosAlbum(scImage, nil, nil, nil);
It still works,but only on-device (not in simulator) .

截图另存为指定名字:
UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];
UIGraphicsBeginImageContext(screenWindow.frame.size);
[screenWindow.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

NSData *screenshotPNG = UIImagePNGRepresentation(screenshot);

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];

NSError *error = nil;
[screenshotPNG writeToFile:[documentsDirectory stringByAppendingPathComponent:@"screenshot.png"] options:NSAtomicWrite error:&error];