在缩小并放大iOS后，闪烁的MapOverlay [英] Flickering MapOverlay after zoom out and zoom in-iOS

问题描述

我有两个问题。首先，一旦我分配内存的坐标，请看下面的代码，我必须释放内存空闲（coords）？其次，如下面的代码所示，我得到覆盖并添加到地图上。但是，有不同的时间戳馈送坐标并且应该更新地图。像雷达地图改变覆盖形状与不同的时间戳。它最初更新很好;然而，一旦用户缩小并放大，它将开始闪烁或闪烁。我不知道为什么这个闪烁发生了？任何人以前都经历过这个问题？

  NSArray * ants = [mapView overlay]; 
 for（bb = 0; bb< [polygonArray count]; bb ++）{
 int attr = [[idArray objectAtIndex：bb] floatValue]; 
 
 
 coords = malloc（sizeof（CLLocationCoordinate2D）* [[polygonArray objectAtIndex：bb] count]）; （int a = 0; a< [[polygonArray objectAtIndex：bb] count]; a ++）{
 coords [a] .latitude = [[[polygonArray objectAtIndex：bb] objectAtIndex：a ] objectAtIndex：0]的doubleValue]; 
 coords [a] .longitude = [[[polygonArray objectAtIndex：bb] objectAtIndex：a] objectAtIndex：1] doubleValue]; 
} 
 polygon = [[MKPolygon alloc] init]; 
 polygon = [MKPolygon polygonWithCoordinates：coords count：[[polygonArray objectAtIndex：bb] count]]; 
 // free（coords）; 
 [previousPolygons addObject：polygon]; 
 
} 
 [mapView addOverlay：polygon]; 
} 
 
} 
 [mapView removeOverlays：ants]; 
  

解决方案

下载苹果

BreadCrumbs演示

应用程序。

使用此演示，您将看到推荐的技术来完成任务。

我在我的应用程序中使用了Demo，它的工作方式就像一个魅力。

MkPolygon的方法对于大多边形不起作用，或更改多边形。

I have two questions. First of all, once I allocate memory for the coordinates please see the code below, do I have to free memory free(coords)? Second, as you seen below code, I get overlay and add on the map. However, there is a different timestamps feeds coordinates and should update map. Like a radar map changing overlay shape with different time stamps.It is updating very well initially; however, once user zoom out and zoom in, it starts flashing or flickering. I wonder why this flickering happens? Anybody has experienced that problem before?

NSArray *ants = [mapView overlays];
for(bb = 0; bb < [polygonArray count]; bb++){
        int attr=[[idArray objectAtIndex:bb]floatValue];


        coords = malloc(sizeof(CLLocationCoordinate2D) * [[polygonArray objectAtIndex:bb] count]);
        for (int a = 0;a < [[polygonArray objectAtIndex:bb] count]; a++){
            coords[a].latitude = [[[[polygonArray objectAtIndex:bb]objectAtIndex:a]objectAtIndex:0]doubleValue];
            coords[a].longitude = [[[[polygonArray objectAtIndex:bb]objectAtIndex:a]objectAtIndex:1]doubleValue];
        }
        polygon = [[MKPolygon alloc]init];
        polygon = [MKPolygon polygonWithCoordinates:coords count:[[polygonArray objectAtIndex:bb]count]]; 
        //free(coords);
        [previousPolygons addObject:polygon];

            }
        [mapView addOverlay:polygon];
        }

    }
[mapView removeOverlays:ants];

解决方案

Download Apples

BreadCrumbs Demo

App.
Using this Demo you see the recommended technic to do your task.
I have used that Demo in my App, and it worked like a charm.

The approach with MkPolygon does not work fine withn big polygons, or changing Polygons.

这篇关于在缩小并放大iOS后，闪烁的MapOverlay的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！