我想在一个地方删除我的地图的所有叠加层,我尝试了不同的方式,但它从来没有工作.
最后尝试我[self.mapView removeOverlays：self.mapView.overlays];它仍然不起作用.任何想法如何删除这些叠加？
谢谢.
更新1
我有错误：malloc：***错误的对象0x5adc0c0：指针被释放没有分配
***在malloc_error_break中设置一个断点来进行调试
我想我知道为什么,但不知道如何解决它？
以下是我需要在mapView上绘制另一行的代码：
// Create a c array of points.
MKMapPoint *pointsArray = malloc(sizeof(CLLocationCoordinate2D) * 2);
// Create 2 points.
MKMapPoint startPoint = MKMapPointForCoordinate(CLLocationCoordinate2DMake(oldLatitude,oldLongitude));
MKMapPoint endPoint = MKMapPointForCoordinate(CLLocationCoordinate2DMake(newLatitude,newLongitude));
// Fill the array.
pointsArray[0] = startPoint;
pointsArray[1] = endPoint;
// Erase polyline and polyline view if not nil.
if (self.routeLine != nil) {
[_routeLine release];
self.routeLine = nil;
}
if (self.routeLineView != nil) {
[_routeLineView release];
self.routeLineView = nil;
}
// Create the polyline based on the array of points.
self.routeLine = [MKpolyline polylineWithPoints:pointsArray count:2];
// Add overlay to map.
[self.mapView addOverlay:self.routeLine];
// clear the memory allocated earlier for the points.
free(pointsArray);
// Save old coordinates.
oldLatitude = newLatitude;
oldLongitude = newLongitude;
所以我释放了以前的叠加层的routeLine对象.所以当我试图删除它,它崩溃,因为它已被释放.
以下是用于添加重叠式视图的mapView代理的代码：
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayView* overlayView = nil;
if(overlay == _routeLine) {
// If we have not yet created an overlay view for this overlay,create it Now.
if(self.routeLineView == nil) {
self.routeLineView = [[[MKpolylineView alloc] initWithpolyline:_routeLine] autorelease];
self.routeLineView.fillColor = [UIColor blueColor];
self.routeLineView.strokeColor = [UIColor blueColor];
// Size of the trace.
self.routeLineView.linewidth = routelinewidth;
}
overlayView = self.routeLineView;
}
return overlayView;
}
如果你们知道如何解决这个问题,从MKMapView中删除所有的叠加层就会很棒！
更新2
我试图没有释放我的routeLine和routeLineView对象,它现在工作.似乎也没有泄漏.所以现在我这样做：
// Erase polyline and polyline view if not nil.
if (self.routeLine != nil) {
//[_routeLine release];
self.routeLine = nil;
}
if (self.routeLineView != nil) {
//[_routeLineView release];
self.routeLineView = nil;
}
解决方法
当您调用removeOverlays：时,地图视图将释放MKOverlay和MKOverlayView对象.
您在_routeLine和_routeLineView中持有您自己的引用.
removeOverlays：被调用后,变量将指向已经释放的内存.当您重新创建折线时,您将被过度释放,从而导致崩溃.
所以删除释放调用：
if (_routeLine != nil) {
[_routeLine release]; // <-- remove this
self.routeLine = nil;
}
if (_routeLineView != nil) {
[_routeLineView release]; // <-- remove this
self.routeLineView = nil;
}