在注释中用文本标签替换图标引脚？ [英] Replace icon pin by text label in annotation?

问题描述

是否可以用动态文本标签替换注释的图钉图标？

Is it possible to replace the pin icon of an annotation by a dynamic text label?

可能使用css，还是动态创建图像？

Maybe using css, or dynamically creating an image?

例如，使用JavaScript在Google Maps API上使用CSS完成标签。

For example a label is done with CSS on Google Maps API with JavaScript.

推荐答案

是的，这是可能的。

在iOS MapKit中，您需要实现 viewForAnnotation 委托方法并返回 MKAnnotationView 添加了 UILabel 。

In iOS MapKit, you'll need to implement the viewForAnnotation delegate method and return an MKAnnotationView with a UILabel added to it.

For示例：

-(MKAnnotationView *)mapView:(MKMapView *)mapView 
    viewForAnnotation:(id<MKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;

    static NSString *reuseId = @"reuseid";
    MKAnnotationView *av = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
    if (av == nil)
    {
        av = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId] autorelease];

        UILabel *lbl = [[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 50, 30)] autorelease];
        lbl.backgroundColor = [UIColor blackColor];
        lbl.textColor = [UIColor whiteColor];
        lbl.alpha = 0.5;
        lbl.tag = 42;
        [av addSubview:lbl];

        //Following lets the callout still work if you tap on the label...
        av.canShowCallout = YES;
        av.frame = lbl.frame;
    }
    else
    {
        av.annotation = annotation;
    }

    UILabel *lbl = (UILabel *)[av viewWithTag:42];
    lbl.text = annotation.title;        

    return av;
}

确保地图视图的委托属性已设置，否则此委托方法将不会被调用，您将获得默认的红色引脚。

Make sure the map view's delegate property is set otherwise this delegate method will not get called and you will get the default red pins instead.

这篇关于在注释中用文本标签替换图标引脚？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！