防止在 MKMapView 中滚动，也在缩放时 [英] Prevent scrolling in a MKMapView, also when zooming

问题描述

一旦用户开始捏住 MKMapView，scrollEnabled 似乎会被破坏.

The scrollEnabled seems to be breakable once the user starts pinching in a MKMapView.

您仍然无法用一根手指滚动，但如果在放大和缩小时用两根手指滚动，您可以移动地图.

You still can't scroll with one finger, but if you scroll with two fingers while zooming in and out, you can move the map.

我试过了:

• 继承 MKMapKit 以禁用其中的滚动视图.
• 实施 –mapView:regionWillChangeAnimated: 以强制居中.
• 禁用 scrollEnabled.

• Subclassing the MKMapKit to disable the scroll view inside it.
• Implementing –mapView:regionWillChangeAnimated: to enforce the center.
• Disabling scrollEnabled.

但没有运气.

谁能告诉我只放大 MKMapView 的可靠方法，这样中心点始终保持在中间?

Can anyone tell me a sure way to ONLY have zooming in a MKMapView, so the center point always stays in the middle ?

推荐答案

您可以尝试使用 UIPinchGestureRecognizer 自己处理捏合手势:

You can try to handle the pinch gestures yourself using a UIPinchGestureRecognizer:

首先将 scrollEnabled 和 zoomEnabled 设置为 NO 并创建手势识别器:

First set scrollEnabled and zoomEnabled to NO and create the gesture recognizer:

UIPinchGestureRecognizer* recognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self
                                                                                 action:@selector(handlePinch:)];
[self.mapView addGestureRecognizer:recognizer];

在识别器处理程序中根据缩放比例调整MKCoordinateSpan:

In the recognizer handler adjust the MKCoordinateSpan according to the zoom scale:

- (void)handlePinch:(UIPinchGestureRecognizer*)recognizer
{
    static MKCoordinateRegion originalRegion;
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        originalRegion = self.mapView.region;
    }    

    double latdelta = originalRegion.span.latitudeDelta / recognizer.scale;
    double londelta = originalRegion.span.longitudeDelta / recognizer.scale;

    // TODO: set these constants to appropriate values to set max/min zoomscale
    latdelta = MAX(MIN(latdelta, 80), 0.02);
    londelta = MAX(MIN(londelta, 80), 0.02);
    MKCoordinateSpan span = MKCoordinateSpanMake(latdelta, londelta);

    [self.mapView setRegion:MKCoordinateRegionMake(originalRegion.center, span) animated:YES];
}

这可能不像 Apple 的实现那样完美，但它应该可以解决您的问题.

This may not work perfectly like Apple's implementation but it should solve your issue.

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