定位 MKMapView 以一次显示多个注释 [英] Positioning MKMapView to show multiple annotations at once

问题描述

我有几个注释要添加到我的 MKMapView(它可以是 0-n 个项目，其中 n 通常约为 5).我可以很好地添加注释，但我想调整地图的大小以一次适合屏幕上的所有注释，但我不知道该怎么做.

I've got several annotations I want to add to my MKMapView (it could 0-n items, where n is generally around 5). I can add the annotations fine, but I want to resize the map to fit all annotations onscreen at once, and I'm not sure how to do this.

我一直在查看 -regionThatFits: 但我不太确定如何处理它.我会发布一些代码来展示我到目前为止所得到的.我认为这通常应该是一项简单的任务，但到目前为止，我对 MapKit 感到有些不知所措.

I've been looking at -regionThatFits: but I'm not quite sure what to do with it. I'll post some code to show what I've got so far. I think this should be a generally straightforward task but I'm feeling a bit overwhelmed with MapKit so far.

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{

location = newLocation.coordinate;
//One location is obtained.. just zoom to that location

MKCoordinateRegion region;
region.center = location;

//Set Zoom level using Span
MKCoordinateSpan span;
span.latitudeDelta = 0.015;
span.longitudeDelta = 0.015;
region.span = span;
// Set the region here... but I want this to be a dynamic size
// Obviously this should be set after I've added my annotations
[mapView setRegion:region animated:YES];

// Test data, using these as annotations for now
NSArray *arr = [NSArray arrayWithObjects:@"one", @"two", @"three", @"four", nil];
float ex = 0.01;
for (NSString *s in arr) {
    JBAnnotation *placemark = [[JBAnnotation alloc] initWithLat:(location.latitude + ex) lon:location.longitude];
    [mapView addAnnotation:placemark];
    ex = ex + 0.005;
}
    // What do I do here?
    [mapView setRegion:[mapView regionThatFits:region] animated:YES];
}

请注意，这一切都是在我收到位置更新时发生的……我不知道这是否适合执行此操作.如果没有，哪里会更好?-viewDidLoad?

Notice, this all happens as I receive a location update... I don't know if that's an appropriate place to do this. If not, where would be a better place? -viewDidLoad?

提前致谢.

推荐答案

从 iOS7 开始，您可以使用 showAnnotations:animated:

As of iOS7 you can use showAnnotations:animated:

[mapView showAnnotations:annotations animated:YES];

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