Question

使用动作handleLongPressOnPhotos将UILongPressGestureRecognizer添加到我的imageView。最相关的代码如下：

- (IBAction)handleLongPressOnPhotos:(UIImageView *)sender{
self.imageWillBeSaved = sender;
UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:nil delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:@"Save the photo" otherButtonTitles: @"Go to the Original photo", nil];
actionSheet.actionSheetStyle = UIActionSheetStyleDefault;
[actionSheet showInView:self.view]; 
[actionSheet release];
}

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{
switch (buttonIndex) {
    case 0:
        UIImageWriteToSavedPhotosAlbum(self.imageWillBeSaved.image, self, @selector(image: didFinishSavingWithError:contextInfo:), nil);

        break;

    default:
        break;
}

}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (error != NULL)
{
    // handle error
}
else 
{
    // handle ok status
}
}

单击操作表上的“保存照片”按钮时，会显示错误消息： - [UILongPressGestureRecognizer image]：无法识别的选择器发送到实例0x21c2a0 代码中有问题吗？提前谢谢！

Answer 1

只需更换前两行..

- (IBAction)handleLongPressOnPhotos:(UIImageView *)sender{
self.imageWillBeSaved = sender;

与..

- (IBAction)handleLongPressOnPhotos:(UIGestureRecognizer *)sender{
self.imageWillBeSaved = sender.view;

这应该有用......大卫很好地解释了这种情况发生的原因。

Answer 2

您的发件人显然是UILongPressGestureRecognizer。

触发手势识别器时触发的方法应如下所示

- (void)nameOfMethodHere:(UIGestureRecognizer *)gestureRecognizer;

参数是识别器，而不是图像视图。如果识别器仅附加到一个视图，则可通过view属性获取。否则，您可以获取长按的位置并点击测试以获取视图。

Answer 3

这适用于UILongPressGestureRecognizer

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(handleLongPress:)];
longPress.minimumPressDuration = 1.0;
[YOURVIEW addGestureRecognizer:longPress];
[longPress release];

这是[{1}}的选择器，您的代码中的问题是，您在UILongPressGestureRecognizer的选择器中传递UIImageView作为参数，只需使用此编辑...

UILongPressGestureRecognizer

使用UIImageWriteToSavedPhotosAlbum保存图像时无法识别的选择器错误

3 个答案: