iphone - 如何使用 UIGestureRecognizers 在多个 UIView 或 UIImageView 上进行点击、捏合和旋转

Question

我不知道如何处理:-/

我只需要在图片上添加贴纸。应用程序将在选择特定贴纸时包含表情符号，心形(图像)等贴纸，它将添加到主图像中，用户可以使用贴纸进行操作，例如旋转，缩放等，用户可以选择多个贴纸并可以进行旋转缩放等添加贴纸，

请指导如何实现这一点，我能够使用单个贴纸执行图像操作我不知道如何执行多个贴纸选择，用户可以再次返回到任何贴纸并对其执行操作。

Answer 1

您可以使用此方法添加手势:

- (void) addGestureRecognizers{
    UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
    [panRecognizer setMinimumNumberOfTouches:1];
    [panRecognizer setMaximumNumberOfTouches:1];
    [self addGestureRecognizer:panRecognizer];

    UIRotationGestureRecognizer *rotateRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];
    self.multipleTouchEnabled = YES;
    [self addGestureRecognizer:rotateRecognizer];

    UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];
    [self addGestureRecognizer:pinchRecognizer];

    UILongPressGestureRecognizer *longPressRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];
    longPressRecognizer.minimumPressDuration = 2.0;
    [self addGestureRecognizer:longPressRecognizer];
}

并实现这些选择器:

- (void) move:(UIPanGestureRecognizer *)recognizer{
    CGPoint translation = [recognizer translationInView:self.superview];
    recognizer.view.center = CGPointMake(recognizer.view.center.x+translation.x, recognizer.view.center.y+translation.y);
    [recognizer setTranslation:CGPointMake(0, 0) inView:self.superview];
}

- (void) rotate:(UIRotationGestureRecognizer *)recognizer{
    NSLog(@"Rotate");
    recognizer.view.transform = CGAffineTransformRotate(
                                                        recognizer.view.transform,
                                                        recognizer.rotation);
    recognizer.rotation = 0;
}

- (void) pinch:(UIPinchGestureRecognizer *)recognizer{
    recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale);
    recognizer.scale = 1; 
}

- (void) longPressed:(UILongPressGestureRecognizer *)recognizer{
    NSLog(@"Long Pressed");
}

注意:根据需要更改值