iOS 4.2 中的地图注释和 MKMapView 有问题吗? [英] Issue with Map Annotation and MKMapView in iOS 4.2?
问题描述
我有一个带有图钉的地图视图，当用户选择一个图钉时，它会转到该图钉的详细信息屏幕.我还有一个表格视图，当用户选择一个项目时，它会转到相同类型的详细视图.
I have a map view with pins that when the user selects a pin it goes to a detail screen for that pin. I also have a table view that when the user selects an item it goes to the same type detail view.
问题来了……
它似乎在从 3.1.3 到 4.1 的所有版本中都可以正常工作.那就是与引脚匹配的详细视图.但是我有一个用户刚刚升级到 iOS 4.2，并说在 4.1 下它工作得很好，但是在 4.2 中，引脚选择将他带到了不同引脚的细节.但是在表格视图中它仍然可以正常工作.
It seems to work fine in everything from 3.1.3 to 4.1. That is the detail view matches with the pin. But I have a user who just upgraded to iOS 4.2 and says that under 4.1 it worked fine, but in 4.2 the pin selection takes him to the detail for a different pin. But in the table view it still works fine.
iOS 4.2 中的 MKMapView 是否有可能改变了 pinID 的选择方式?
Is it possible that there was a change in MKMapView in iOS 4.2 that changes how the pinID is selected?
添加 - 我已经添加了 viewForAnnotation 和 checkButtonTapped 的相关部分
Addition - I have added the relevant parts of viewForAnnotation and checkButtonTapped
- (MKPinAnnotationView *)mapView:(MKMapView *)eMapView viewForAnnotation:(id <MKAnnotation>)annotation {
int postTag = 0;
MKPinAnnotationView *pinView = (MKPinAnnotationView *)[eMapView dequeueReusableAnnotationViewWithIdentifier:@"Pin"];
if(pinView == nil) {
pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"Pin"];
pinView.frame = CGRectMake(0, 0, 25, 25);
} else {
pinView.annotation = annotation;
}
// Set up the Right callout
UIButton *myDetailButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
myDetailButton.frame = CGRectMake(0, 0, 23, 23);
myDetailButton.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
myDetailButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
[myDetailButton addTarget:self action:@selector(checkButtonTapped:) forControlEvents:UIControlEventTouchUpInside];
// Identify which pin is being selected
if ([[annotation title] isEqualToString:@"Current Location"]) {
postTag = 99999;
} else {
postTag = [annotation getPinID];
}
myDetailButton.tag = postTag;
pinView.rightCalloutAccessoryView = myDetailButton;
pinView.animatesDrop = YES;
// Set to show a callout on the pin
pinView.canShowCallout = YES;
return pinView;
}
// Method to show detail view when the callOut button is selected
- (IBAction) checkButtonTapped: (id) sender {
int nrButtonPressed = ((UIButton *)sender).tag;
if (nrButtonPressed < 99999) {
if (self.showDetailView == nil) {
DetailData *tmpViewController = [[DetailData alloc] initWithNibName:@"Detail" bundle:nil];
self.showDetailView = tmpViewController;
[tmpViewController release];
}
buttonDetail = [[mapView annotations] objectAtIndex:(nrButtonPressed-1)];
NSMutableArray *tmpArray = [NSMutableArray arrayWithObjects: [buttonDetail getDataI], [buttonDetail getDataII], [buttonDetail getDataIII], [buttonDetail getDataIV], [buttonDetail getDataV], nil];
self.showDetailView.eventData = [[NSMutableArray alloc] initWithArray:tmpArray copyItems:YES];
[self.navigationController pushViewController:self.showDetailView animated:YES];
[self.showDetailView.eventData release];
}
}
如您所见，在 checkButtonTapped 中，我记录了选定的引脚，然后从该引脚的注释中收集数据.问题似乎是 nrButtonPressed 现在不正确.但是在 4.1 编译时就可以了
As you can see, in checkButtonTapped I record the pin selected then collect the data from the annotation for that pin. The problem seems to be that nrButtonPressed is now incorrect. But it is fine when compiled in 4.1
推荐答案
在 checkButtonTapped 中，使用按钮的标签来识别注解.通过调用自定义方法getPinID在viewForAnnotation中设置按钮的标签.
In checkButtonTapped, the annotation is being identified using the button's tag. The button's tag is set in viewForAnnotation by calling the custom method getPinID.
按钮标签用作 mapView 注释数组的索引.目前尚不清楚 getPinID 方法如何确定它在 mapView 的 annotations 数组中的索引.我不确定假设注释将位于数组中的特定索引处是否明智.即使 mapView 不打乱注释，您的应用也可能会不断添加和删除注释.
The button tag is used as the index into the mapView annotations array. It's not clear how the getPinID method figures out what index it is at in the mapView's annotations array. I'm not sure it's wise to assume an annotation is going to be at a specific index in the array. Even if mapView doesn't shuffle the annotations around, your app might be constantly adding and removing annotations.
由于您在注解视图中将按钮指定为标注附件，而不是使用按钮标签来标识注解，因此可以使用 mapView 自己的 mapView:annotationView:calloutAccessoryControlTapped: 委托方法.
Because you are assigning the button as a callout accessory in the annotation view, rather than using a button tag to identify the annotation, you can use the mapView's own mapView:annotationView:calloutAccessoryControlTapped: delegate method.
不要在按钮上执行 addTarget 并让它调用您的自定义方法，而是删除对 addTarget 的调用并实现 calloutAccessoryControlTapped.
Instead of doing addTarget on the button and having it call your custom method, remove the call to addTarget and implement calloutAccessoryControlTapped.
在 calloutAccessoryControlTapped 中，您可以使用 view.annotation 直接访问注解.您还可以轻松检查注解是否为用户位置":
In calloutAccessoryControlTapped, you can directly access the annotation using view.annotation. You can also easily check if the annotation is the "user location":
- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
{
if (view.annotation == mapView.userLocation)
return;
buttonDetail = (MyCustomAnnotationClass *)view.annotation;
//show detail view using buttonDetail...
}
此外，在 viewForAnnotation 中，您每次都在创建一个按钮，即使视图正在被重复使用.因此，重复使用的注释视图可能最终会得到多个按钮.该按钮只能在 if(pinView == nil) 部分中创建和设置.
Additionally, in viewForAnnotation, you are creating a button every time even if the view is being re-used. So a re-used annotation view probably ends up getting multiple buttons on top of each other. The button should only be created and set in the if(pinView == nil) section.
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