objective-c - Objective C 中的旋转问题

Question

在我的应用程序中，从滚动视图拖放图像视图。放下后，当用户触摸我放下的东西时，我想分别旋转图像。在这里，我只能旋转最后拖动的图像。我无法旋转以前拖动的图像。我在移动到旋转的触摸中使用此代码

[myview setTransform:CGAffineTransformRotate([myview transform], angleInRadians)];

Answer 1

你可以使用 UIRotationGestureRecognizer

UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotatePiece:)];
rotationGesture.delegate=self;
[YourImageview addGestureRecognizer:rotationGesture];


- (void)rotatePiece:(UIRotationGestureRecognizer *)gestureRecognizer
 {
     [self adjustAnchorPointForGestureRecognizer:gestureRecognizer];

if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
    [gestureRecognizer view].transform = CGAffineTransformRotate([[gestureRecognizer view] transform], [gestureRecognizer rotation]);
    [gestureRecognizer setRotation:0];
}
}