每个针脚都有不同的自定义图片 [英] Different custom image for each pin
问题描述
这听起来像是一个通用的问题，但是我只想为所有图钉使用相同的图像找到答案，而我却没有.
This may sound like a generic question but I've only found answers if I want the same image for all my pins, which i don't.
这就是我现在的工作方式:
That's how i'm working right now :
我所有的位置都存储在一个位置数组中(带有长，纬度，名称，引脚名称的自定义类).
I have all my locations in an array of Locations (custom class with long, lat, name, pin name).
在viewdidLoad中，我循环该数组并为找到的每个对象创建引脚，请参见以下代码:
in the viewdidLoad I loop that array and create my pins with every object found, see following code :
for(int i = 0 ; i<[_locationList count] ; i++)
{
Location *item = [_locationList objectAtIndex:i];
CLLocationCoordinate2D coordinate;
coordinate.latitude = item.locationLatitude;
coordinate.longitude = item.locationLongitude;
NSString *title = item.locationName;
CustomAnnotation* ann = [CustomAnnotation new];
ann.name = title;
ann.coordinate = coordinate;
ann.pinName = [NSString stringWithFormat:@"pin%i.png",item.idPin];
[self.map addAnnotation:ann];
}
这很简单，部分来自CustomAnnotation类，它是以下代码:
This is pretty straight forward, part from the CustomAnnotation class, which is the following code :
@interface CustomAnnotation : MKPointAnnotation <MKAnnotation>{
}
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSString *description;
@property (nonatomic, retain) NSString *pinName;
@end
这全都是我在互联网上看到的东西，我有点相信到那时为止，这都是正确的.
This is all from stuff i've seen around the internet, and I kinda believe it's all correct up to that point.
在我看来，我仍在创建非常经典的图钉，它们仅具有一个属性(pinName)，这就是为什么它来自自定义类的原因.
In my mind, i'm still creating very classic pins, they just have one more property (pinName), which is why it's coming from the custom class.
现在，在viewForAnnotation中，我绝对不知道如何告诉它获取该pinName并使用它.
Now, in the viewForAnnotation, i have absolutly NO IDEA how to tell it to get that pinName and use it.
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
// If it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
// Handle any custom annotations.
if ([annotation isKindOfClass:[MKPointAnnotation class]])
{
// Try to dequeue an existing pin view first.
MKAnnotationView *pinView = (MKAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:@"CustomPinAnnotationView"];
if (!pinView)
{
// If an existing pin view was not available, create one.
pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"CustomPinAnnotationView"];
pinView.canShowCallout = YES;
pinView.image = // I wanted to write annotation.pinName But it's just not that.
pinView.calloutOffset = CGPointMake(0, 32);
}else {
pinView.annotation = annotation;
}
return pinView;
}
return nil;
}
我想念什么?我显然做错了事，但我无法弄清楚，我仍然对MKAnnotationsView&的区别感到困惑. MKPointAnnotation& MKPinAnnotation，...
What am I missing? I'm obviously doing something wrong but i jsut can't figure it out, and i'm still quite confused with the differences between MKAnnotationsView & MKPointAnnotation & MKPinAnnotation, ...
更多信息:引脚名称是"pinX.png"，X是1到12之间的数字.我只想使用该名称，以便程序可以在图片所在的资源中找到它.
More info : the pin names are " pinX.png ", X being a number between 1 and 12. I just want to use that name so the program can find it in the ressources where the picture lies.
推荐答案
由于注释的类型为CustomAnnotation，因此检查注释的类型是否为MKPointAnnotation而不是MKPointAnnotation更为准确.
Since your annotations are of type CustomAnnotation, it would be more accurate to check if the annotations are of that kind instead of MKPointAnnotation.
然后，将annotation参数转换为自定义类将使您可以轻松地在其中访问自定义属性，如下所示:
Then, casting the annotation parameter to your custom class will let you easily access the custom properties in it like this:
CustomAnnotation *ca = (CustomAnnotation *)annotation;
pinView.image = [UIImage imageNamed:ca.pinName];
但是，由于每个注解的图像可能不同，因此应在创建注解视图或后将其设置为 (不仅在if (!pinView)阻止-否则注释可能最终会重新使用不再可见的另一个注释中的视图，并显示错误的图片.
However, because the image can be different for each annotation, you should set it after the annotation view has been created or dequeued (not only in the if (!pinView) block -- otherwise an annotation could end up re-using the view from another annotation no longer visible and the wrong image will show).
更新后的方法如下:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
// If it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
// Handle any custom annotations.
if ([annotation isKindOfClass:[CustomAnnotation class]])
{
// Try to dequeue an existing pin view first.
MKAnnotationView *pinView = (MKAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:@"CustomPinAnnotationView"];
if (!pinView)
{
// If an existing pin view was not available, create one.
pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"CustomPinAnnotationView"];
pinView.canShowCallout = YES;
pinView.calloutOffset = CGPointMake(0, 32);
//NOTE:
//If the calloutOffset needs to be different for each image,
//then this line should also be set below with the image.
}
else {
pinView.annotation = annotation;
}
//Set image on view AFTER we have a new or dequeued view
//because image is based on each annotation...
CustomAnnotation *ca = (CustomAnnotation *)annotation;
pinView.image = [UIImage imageNamed:ca.pinName];
//Might want to check that the UIImage is not nil
//in case pinName is invalid since that would result in
//an invisible annotation view. If the UIImage is nil,
//set pinView.image to some default image.
return pinView;
}
return nil;
}
有关MapKit类之间差异的困惑，请参见:
For the confusion about the differences between the MapKit classes, see:
-
我应该使用MKAnnotation，MKAnnotationView还是MKPinAnnotation?.即使该问题被标记为MonoTouch，它仍然适用.
Should I use MKAnnotation, MKAnnotationView or MKPinAnnotation?. Even though that question is tagged MonoTouch, it still applies.
MKMapView，animateDrop?可能也有帮助.
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