在iPhone上的MKMapView中移动注释时避免闪烁 [英] Avoid flicker when moving annotations in a MKMapView on iPhone

问题描述

据我所知，没有办法移动注释而不删除&将它重新添加到MapView（也许我错了）。

有没有办法阻止MapView在删除&之间重新绘制重新添加注释？现在，删除注释后重新绘制会导致没有注释的帧，因此它似乎闪烁。

我需要一个适用于iOS 3.1更新的解决方案。 / p>

谢谢

解决方案

我想出了如何实现无闪烁注释更新使用以下代码。在坚果壳中，您将新的引脚添加为FIRST，然后删除旧的引脚。我还没有精简我的代码，但你会明白这一点。

   - （void）replacePin：（NSString *） title SubTitle：（NSString *）subTitle Location：（CLLocationCoordinate2D）location PinType：（MapAnnotationType）pinType Loading：（BOOL）loading进度：（float）进度
 {
 //查找并退役旧的pin ...（基本上将其标记为以后删除）
 for（MyMapAnnotation *注释在map.annotations中）
 {
 if（！[annotation isKindOfClass：[MKUserLocation class]]）
 {
 if（[annotation.title isEqualToString：title]）
 annotation.decommissioned = YES; 
} 
} 
 
 //添加新引脚... 
 MyMapAnnotation * stationPin = nil; 
 stationPin = [[MyMapAnnotation alloc] initWithCoordinate：Location 
 annotationType：pinType 
 title：title 
 subtitle：subTitle 
 loading：loading 
 decommissioned：NO 
进展：进展]; 
 [map addAnnotation：stationPin]; 
 [stationPin release]; 
} 
  

然后我打电话来搜索并删除任何退役的引脚：

   - （MKAnnotationView *）mapView：（MKMapView *）mapView viewForAnnotation：（id< MKAnnotation>）注释
 {
 MKAnnotationView * annotationView = nil; 
 
 if（！[annotation isKindOfClass：[MKUserLocation class]]）
 {
 MyMapAnnotation * annotation =（MyMapAnnotation *）annotation; 
 
 //你自己的详细信息... 
 
 //删除任何退役的引脚... 
 [self performSelectorOnMainThread：@selector（deletePin :) withObject：annotation .title waitUntilDone：NO]; 
} 
返回annotationView; 
 
} 
  

最后，在后台摆脱旧针：

   - （void）deletePin：（NSString *）stationCode 
 {
 for（MyMapAnnotation * annotation）在map.annotations中）
 {
 if（！[annotation isKindOfClass：[MKUserLocation class]]）
 {
 if（[annotation.title isEqualToString：stationCode]）
 {
 if（annotation.decommissioned）
 [map removeAnnotation：annotation]; 
} 
} 
} 
} 
  

As far as I know, there isn't a way to move an annotation without removing & re-adding it to the MapView (Maybe I'm wrong).

Is there a way to prevent the MapView from being re-drawn between removing & re-adding the annotation? Right now the re-draw after removing the annotation causes a frame without the annotation, so it appears to flicker.

I need a solution that works in iOS 3.1 updates.

Thanks

解决方案

I figured out how achieve flicker free annotation "updates" using the below code. In a nut shell, you add your new pin FIRST, then delete the old one AFTER. I haven't streamlined my code yet but you'll get the idea.

-(void)replacePin:(NSString *)title SubTitle:(NSString *)subTitle Location:(CLLocationCoordinate2D)location PinType:(MapAnnotationType)pinType Loading:(BOOL)loading Progress:(float)progress
{
    //Find and "decommission" the old pin... (basically flags it for deletion later)
    for (MyMapAnnotation *annotation in map.annotations) 
    {
        if (![annotation isKindOfClass:[MKUserLocation class]])
        {
            if ([annotation.title isEqualToString:title])
                annotation.decommissioned = YES;
        }
    }

    //add the new pin...
    MyMapAnnotation *stationPin = nil;
    stationPin = [[MyMapAnnotation alloc] initWithCoordinate:Location
                                              annotationType:pinType
                                                       title:title
                                                    subtitle:subTitle
                                                     loading:loading
                                              decommissioned:NO
                                                    progress:progress];
    [map addAnnotation:stationPin];
    [stationPin release];
}

Then AFTER, I make the call to search for and remove any decommissioned pins:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    MKAnnotationView* annotationView = nil;

    if (![annotation isKindOfClass:[MKUserLocation class]])
    {
        MyMapAnnotation* annotation = (MyMapAnnotation*)annotation;

        //your own details...

        //delete any decommissioned pins...
        [self performSelectorOnMainThread:@selector(deletePin:) withObject:annotation.title waitUntilDone:NO];
    }
    return annotationView;

}

And finally, in the background get rid of the old pin:

-(void)deletePin:(NSString *)stationCode
{
    for (MyMapAnnotation *annotation in map.annotations) 
    {
        if (![annotation isKindOfClass:[MKUserLocation class]])
        {
            if ([annotation.title isEqualToString:stationCode])
            {  
                if (annotation.decommissioned)
                    [map removeAnnotation:annotation];
            }
        }
    }
}

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