Question

我正在尝试实现与Uber相同的地图行为。当用户使用捏合或双击缩放地图时，我想保持地图居中。我尝试实现自己的手势识别器，但结果不是很好...... 有没有人知道如何做到这一点？

谢谢！

Answer 1

对于那些对解决方案感兴趣的人，我设法做到了。

首先，您需要在viewDidload中添加手势识别器

UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchOnMap:)];
[pinch setDelegate:self];
[pinch setDelaysTouchesBegan:YES];
[self.mapGestureContainer addGestureRecognizer:pinch];

UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(zoomInGesture:)];
gestureRecognizer.delegate = self;
[gestureRecognizer setDelaysTouchesBegan:YES];
gestureRecognizer.numberOfTapsRequired = 2;
[self.mapGestureContainer addGestureRecognizer:gestureRecognizer];

然后实现手势功能，它将根据捏缩比例处理缩放。我添加了一个小延迟以避免过多处理。

-(void) zoomInGesture:(UITapGestureRecognizer *) recognizer {
    currentRegion = self.mapView.region;
    currentSpan = self.mapView.region.span;
    isZoomingWithDoubleTap = YES;

    MKCoordinateRegion region = currentRegion;
    MKCoordinateSpan span = currentSpan;

    span.latitudeDelta = currentSpan.latitudeDelta / 2.3;
    span.longitudeDelta = currentSpan.longitudeDelta / 2.3;
    region.span = span;

    [self.mapView setRegion:region animated:YES];
}

//Gesture used when the user pinch the area of the map
- (void) pinchOnMap:(UIPinchGestureRecognizer *) recognizer {

    if (recognizer.state == UIGestureRecognizerStateBegan) {
        isPinching = YES;
        self.mapView.scrollEnabled = NO;
        self.mapView.userInteractionEnabled = NO;

        currentRegion = self.mapView.region;
        currentSpan = self.mapView.region.span;
        lastZoomTime = [[NSDate date] timeIntervalSince1970];
    }

    if (recognizer.state == UIGestureRecognizerStateEnded) {
        isPinching = NO;
        self.mapView.scrollEnabled = YES;
        self.mapView.userInteractionEnabled = YES;
    }

    if (recognizer.state == UIGestureRecognizerStateChanged) {
        if (([[NSDate date] timeIntervalSince1970] * 1000) - lastZoomTime >= 20) {
            lastZoomTime = [[NSDate date] timeIntervalSince1970] * 1000;

            MKCoordinateRegion region = currentRegion;
            MKCoordinateSpan span = currentSpan;
            span.latitudeDelta = currentSpan.latitudeDelta / recognizer.scale;
            span.longitudeDelta = currentSpan.longitudeDelta / recognizer.scale;
            region.span = span;
            [self.mapView setRegion:region animated:NO];
        }
    }
}

Answer 2

在地图视图委托中，执行此操作

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation 
{
   [mapView setCenterCoordinate:userLocation.location.coordinate animated:YES];
}

MkmapView：如何在用户缩放时保持地图居中

2 个答案: