Objective c MKMapView未刷新批注

显然，我有一个MKMapView，它显示了用户周围的住房位置

我有一个半径工具，当进行选择时，注释应该根据用户周围的距离添加/删除

我有它添加/删除罚款，但由于某种原因，注释不会显示，直到我放大或缩小

这是基于距离添加/删除注释的方法。我尝试了两种不同的方法

将新注释添加到数组中，然后通过[mapView addAnnotations:NSArray]将其添加到地图中

使用[mapView addAnnotation:MKMapAnnotation]添加找到的注释

一,

此外，要在可能工作的地方强制刷新saw，请执行以下操作：

self._mapView.showsUserLocation = NO;
self._mapView.showsUserLocation = YES;

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非常感谢您的帮助，并一如既往地感谢您抽出时间阅读

我猜updateBasedDistance:是从后台线程调用的。核对NSLog@Am我在UI线程中找到了%d、 [NSThread isMainThread]；。如果为0，则应将removeAnnotations:和addAnnotation:移动到performSelectorOnMainThread:调用，或将GCD块移动到主线程上。

我猜updateBasedDistance:是从后台线程调用的。核对NSLog@Am我在UI线程中找到了%d、 [NSThread isMainThread]；。如果为0，则应将removeAnnotations:和addAnnotation:移动到performSelectorOnMainThread:调用，或在主线程上使用GCD块。

Ah！为什么我没看到呢。谢谢你，先生。谢谢你，我也有同样的问题，这个问题解决了。你帮我省了至少几个小时的头痛。啊！为什么我没看到呢。谢谢，先生。谢谢，我也遇到了同样的问题，这个问题解决了。你帮我省了至少几个小时的头痛。

- (void)updateBasedDistance:(NSNumber *)distance {

    //Setup increment for HUD animation loading
    float hudIncrement = ( 1.0f / [[[[self appDelegate] rssParser]rssItems] count]);

    //Remove all the current annotations from the map
    [self._mapView removeAnnotations:self._mapView.annotations];

    /* 
     I have an array that holds all the annotations on the map becuase 
     a lot of filtering/searching happens. So for memory reasons it is
     more efficient to load annoations once then add/remove as needed.
    */
    for (int i = 0; i < [annotations count]; i++) {

        //Current annotations location
        CLLocation *tempLoc = [[CLLocation alloc] initWithLatitude:[[annotations objectAtIndex:i] coordinate].latitude longitude:[[annotations objectAtIndex:i] coordinate].longitude];

        //Distance of current annotaiton from user location converted to miles
        CLLocationDistance miles = [self._mapView.userLocation.location distanceFromLocation:tempLoc] * 0.000621371192;

        //If distance is less than user selection, add it to the map. 
        if (miles <= [distance floatValue])
            [self._mapView addAnnotation:[annotations objectAtIndex:i]];

        //For some reason, even with ARC, helps a little with memory consumption
        tempLoc = nil;

        //Update a progress HUD I use. 
        HUD.progress += hudIncrement;
    }
}

[self._mapView setNeedsDisplay];
[self._mapView setNeedsLayout];

self._mapView.showsUserLocation = NO;
self._mapView.showsUserLocation = YES;