Question

我对Objective-C只有几个月的经验。

我有一个代码来搜索客户地址列表，然后显示这些地址的注释。由于客户覆盖了许多地区，我想让地图视图的中心和跨度适应结果。

因此，我计划记录所有搜索到的地方标记并计算平均纬度和经度。以下是我的代码

self.mapView.mapType = MKMapTypeStandard; 
for (Customer *customer in customers) {
    CLGeocoder *geoCoder = [[CLGeocoder alloc] init];
    NSString *customerAddress = [Customer getWholeAddressOfCustomer:customer];
    NSString *color = @"";
    if([customer.status isEqualToString:@"1"])
    {
        color = @"Green";
    }else if ([customer.status isEqualToString:@"2"]) {
        color = @"Yellow";
    }else if ([customer.status isEqualToString:@"3"])
    {
        color = @"Red";
    }else {
        color = customer.status;
    }
    [geoCoder geocodeAddressString:customerAddress completionHandler:^(NSArray *placemarks, NSError *error) 
     {
         [NSThread sleepForTimeInterval:0.25];
         if (placemarks.count == 0)
         {

             NSLog(@"No place for customer %@ was found",customerAddress);
         }

         CLPlacemark *placemark = [placemarks objectAtIndex:0];

         if(placemark.location.coordinate.latitude != 0.000000 && placemark.location.coordinate.longitude != 0.000000)
         {
             CustomerAnnotation *annotation = [[CustomerAnnotation alloc]initWithCoordinate:placemark.location.coordinate andName:customer.name andNumber:customer.customerNo andColor:color];  

             [self.mapAnnotations addObject:annotation];

         }

     }];

}
CLLocationDegrees totalLatitude=0;
CLLocationDegrees totalLongitude = 0;
for (int i=0; i < [self.mapAnnotations count]; i++) {
    totalLatitude += [(CustomerAnnotation *)[self.mapAnnotations objectAtIndex:i] coordinate].latitude;
    totalLongitude += [(CustomerAnnotation *)[self.mapAnnotations objectAtIndex:i] coordinate].longitude;
    [self.mapView addAnnotation:[self.mapAnnotations objectAtIndex:i]];

}

MKCoordinateRegion focusRegion;
focusRegion.center.latitude = totalLatitude/[self.mapAnnotations count];
focusRegion.center.longitude = totalLongitude/[self.mapAnnotations count];
focusRegion.span.latitudeDelta = 20; //will modify this parameter later to self adapt the map
focusRegion.span.longitudeDelta = 20;
[self.mapView setRegion:focusRegion animated:YES];

但问题是时间问题，如This problem

在获取那些地方标记之前执行setRegion。在该链接的解决方案中，我应该在完成块中调用一个方法。但是这个解决方案不适合多地址问题，因为我需要在setRegion之前将所有地方标记添加到我的方法中。

无论如何在从geocodeAddressString获取所有结果后执行方法？

提前致谢。

Answer 1

问题已解决。

在块之外，我使用计数器记录添加的注释。

__block int customerCount = 0;

当此计数等于整数时，自动聚焦所有客户的中心区域。

if (customerCount == [customers count]) {
   //Set the focus
}

如何根据geocodeAddressString的搜索结果设置焦点中心

1 个答案: