Trung tâm cá nhân
sách gpt4 ăn đã đi

iphone - UIGestureRecognizer 结尾

In lại 作者：太空狗 更新时间：2023-10-30 03:21:32 30 4
mua khóa gpt4 giày nike

我想在我的 iPhone 应用程序中处理旋转手势并在此期间旋转 imageView。在手势结束时，我想将 imageView 旋转到固定位置。所以，即。如果我将 imageView 从 0 弧度旋转到 M_PI/2 弧度，但在中途的某个地方我以手势结束。结束后我想测试角度，如果它接近 M_PI/2，则将其设置为 M_PI/2，否则设置为 0。
这是我尝试执行此操作的代码:

我创建识别器并将其添加到我的 View 中。

UIGestureRecognizer *recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(gestureRecognized:)];
recognizer.delegate = self;
[self addGestureRecognizer:recognizer];
[recognizer release];

委托(delegate)方法:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    if (_imageView) {
        trả về CÓ;
    }
    trả về KHÔNG;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    trả về CÓ;
}

手势识别方法:

- (void)gestureRecognized:(UIRotationGestureRecognizer *)recognizer {
    _imageView.transform = CGAffineTransformMakeRotation(recognizer.rotation);
}

这些方法都有效，但这是我尝试结束手势的方法。这不起作用:

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    NSLog(@"gesture end");
}

还有一个关于转换的小问题。有时会回到 0 弧度。

欢迎任何建议。谢谢!

câu trả lời hay nhất

我在其他论坛上找到了答案。我希望这也会对其他人有所帮助。答:

You can detect the end of the gesture by checking the UIRotationGestureRecognizer's state in your action method. If [gestureRecognizer state] == UIGestureRecognizerStateEnded then it's done. If something had instead caused it to be cancelled (for instance, a phone call coming in) then you'd see it end in UIGestureRecognizerStateCancelled instead.

If you want to apply the recognizer's rotation directly to your view rather than treat it as a delta from the previous location you can set the recognizer's rotation the its state is UIGestureRecognizerStateBegan, and then it will calculate offsets from that value and you can apply them directly. This just requires that you remember the rotation you last ended at, and then you can do something like [gestureRecognizer setRotation:lastAppliedRotation] when the recognizer's state is UIGestureRecognizerStateBegan.

关于iphone - UIGestureRecognizer 结尾，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4951617/

30 4 0
Đề xuất bài viết: Objective-C#导入循环
Đề xuất bài viết: objective-c - 在 Objective-C 中使用类别的私有(private)方法 : calling super from a subclass
Đề xuất bài viết: objective-c - 跟踪所有 ObjC 方法调用？
Đề xuất bài viết: objective-c - Sprite Kit 的主要 iOS9 性能问题
太空狗
Hồ sơ

Tôi là một lập trình viên xuất sắc, rất giỏi!

Nhận phiếu giảm giá taxi Didi miễn phí
Phiếu giảm giá taxi Didi
Các bài viết phổ biến trên toàn bộ trang web
Chứng chỉ ICP Bắc Kinh số 000000
Hợp tác quảng cáo: 1813099741@qq.com 6ren.com
Xem sitemap của VNExpress