[iOS] Share Screenshot to Facebook

如何將手機螢幕截圖分享到臉書︰

 

設定Navigation Bar按鈕

- (void)viewDidLoad
{
        UIBarButtonItem *shareBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(saveScreenshotToPhotosAlbum:)];
        //[self.navigationItem setRightBarButtonItem:shareBtn];
        [self.navigationItem setRightBarButtonItems:[self.navigationItem.rightBarButtonItems arrayByAddingObject:shareBtn]];
}

 

按鈕事件

- (void)saveScreenshotToPhotosAlbum:(UIView *)view
{
    if([SLComposeViewController isAvailableForServiceType:SLServiceTypeFacebook]){
        self.mySLComposerSheet = [[SLComposeViewController alloc] init];
        self.mySLComposerSheet = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
        [self.mySLComposerSheet setInitialText:@"Some Text"];
        [self.mySLComposerSheet addImage:[self captureView:self.view]];
        [self presentViewController:self.mySLComposerSheet animated:YES completion:nil];
    }
}

 

螢幕截圖

- (UIImage*)captureView:(UIView *)view
{
    
    CGRect rect = [[UIScreen mainScreen] bounds];
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [view.layer renderInContext:context];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    // 以下是為了刪除上方因NavigationBar造成的空白
    CGFloat navigationBarHeight = self.navigationController.navigationBar.frame.size.height;
    rect.size.height = self.view.frame.size.height - navigationBarHeight;
    //NSLog(@"rect.size.height=%f", rect.size.height);
    
    UIGraphicsBeginImageContext(rect.size);
    [img drawAtPoint:CGPointMake(0, navigationBarHeight * -1)];
    UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return croppedImage;
}

 

參考︰

http://stackoverflow.com/questions/16241377/share-screenshot-on-facebook