为iPhone Mapkit创建自定义引脚

Question

我正在尝试一些不同的东西。

我使用MKPinAnnotationView和继承的图像实例而不是类。以下是viewForAnnotation的代码。但它不起作用。什么都没有显示出来。

我也尝试使用MKAnnotationView并得到相同的结果。

- (MKAnnotationView *)mapView:(MKMapView *)eMapView viewForAnnotation:(id <MKAnnotation>)annotation {

    int postTag = 0;

    MKAnnotationView *pinView = (MKAnnotationView*)[eMapView dequeueReusableAnnotationViewWithIdentifier:@"Pin"];

    if(pinView == nil) {

        pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"Pin"];
        pinView.frame = CGRectMake(0, 0, 25, 25);

    } else {

        pinView.annotation = annotation;

    }

    pinView.image = [UIImage alloc];

    NSString *data_annotation = [annotation getData];

    if([data_annotation length] == 0) {
        pinView.image = [UIImage imageNamed:@"pinYellow.png"];          
    //  pinView.pinColor = MKPinAnnotationColorGreen;
    }
    else if(([[data_annotation rangeOfString:@"GRAY"].location != NSNotFound)){
            pinView.image = [UIImage imageNamed:@"pinGray.png"];            
    //  pinView.pinColor = MKPinAnnotationColorPurple;
    }
    else {
        pinView.image = [UIImage imageNamed:@"pinRed.png"];         
    //  pinView.pinColor = MKPinAnnotationColorRed;
    }

    // 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;
}