Iphone 地图视图注释平差

大家好，当用户进入下面的代码时，我正试图更改注释的图像

- (void)locationManager:(CLLocationManager *)manager   didUpdateToLocation:(CLLocation *)newLocation  fromLocation:(CLLocation *)oldLocation
{
    for (int i = 0; i < [_annotationArray count]; i++)
    {
        //MKAnnotation xxx = [_annotationArray objectAtIndex:i];

        Shadows* shadowObj2 = [_shadowArray objectAtIndex:i];

        NSLog(@"%@",_shadowArray);

        CLLocationCoordinate2D location3;

        location3.latitude  =  [shadowObj2.position_x floatValue];
        location3.longitude =  [shadowObj2.position_y floatValue];

        CLLocation* locationold = [[CLLocation alloc] initWithLatitude:location3.latitude longitude:location3.longitude];

        CLLocationDistance kilometers = [newLocation distanceFromLocation:locationold];

        //temp = [kilometers intValue];

        if (kilometers > 50 && kilometers <100)
        {
            MKAnnotationView* newA = [[MKAnnotationView alloc] initWithAnnotation:[_annotationArray objectAtIndex:i] reuseIdentifier:@"annotation1"];
            newA.image = [UIImage imageNamed:@"shadowS.png"];
            newA.canShowCallout = YES;
        }

        [locationold release];
        //[shadowObj2 release];
    }

}

-（void）locationManager:（CLLocationManager*）manager didUpdateToLocation:（CLLocation*）newLocation fromLocation:（CLLocation*）oldLocation
{
对于（int i=0；i<[u注释数组计数]；i++）
{
//MKAnnotation xxx=[\u annotationArray objectAtIndex:i]；
Shadows*shadowObj2=[\u shadowArray objectAtIndex:i]；
NSLog（@“%@”，_shadowArray）；
CLLocationCoordination2d location3；
位置3.latitude=[shadowObj2.position_x floatValue]；
location3.longitude=[shadowObj2.position_y floatValue]；
CLLocation*locationold=[[CLLocation alloc]initWithLatitude:location3.纬度经度：location3.经度]；
CLLocationDistance km=[newLocation distanceFromLocation:locationold]；
//温度=[数值]；
如果（km>50&&km，则可以按照教程进行自定义注释

我认为此代码与地图视图没有任何关系，您正在使用新图像分配一个新的MKAnnotationView实例。这不会更改地图上已有的实例。您需要做的是检查地图视图中的注释距离，然后更改其图像