iphone - 将多行字幕添加到 MKAnotationView Xcode

Question

我在 Xcode 4.2 中显示多行 MKAnnotaion 时遇到问题

这是我的代码，它显示注释的单行字幕。

  -(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:
    (id <MKAnnotation>)annotation {
    MKPinAnnotationView *pinView = nil; 
    if(annotation != mapView.userLocation) 
    {

        static NSString* MyAnnotationIdentifier = @"MyAnnotationIdentifier";
        MKPinAnnotationView* customPinView = [[[MKPinAnnotationView alloc]
                                               initWithAnnotation:annotation     reuseIdentifier:MyAnnotationIdentifier] autorelease];        
        //--- adding pin color and animation
        customPinView.pinColor = MKPinAnnotationColorRed;
        customPinView.animatesDrop = YES;
        customPinView.canShowCallout = YES;              
        return customPinView;
    }
    else
    {
        pinView.annotation = annotation;
    }
    return pinView;
}

那么如何添加多行字幕呢？

提前致谢。

Answer 1

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{   
    MKAnnotationView *annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"loc"];

    // Button
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 23, 23);
button.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

[button setImage:[UIImage imageNamed:yourImageName] forState:UIControlStateNormal];
[advertButton addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];

annView.rightCalloutAccessoryView = button;


    // Image and two labels
    UIView *leftCAV = [[UIView alloc] initWithFrame:CGRectMake(0,0,23,23)];
    [leftCAV addSubview : yourImageView];
    [leftCAV addSubview : yourFirstLabel];
    [leftCAV addSubview : yourSecondLabel];
    annotationView.leftCalloutAccessoryView = leftCAV;

    annotationView.canShowCallout = YES;

    return pin;
}

另请参阅此链接以获取详细信息

如何为 MKAnnotation 的字幕显示 2 行文本并更改右侧按钮的图像？

Answer 2

请使用这个

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

        if ([annotation isKindOfClass:[MKUserLocation class]])
            return nil;
        if ([annotation isKindOfClass:[CustomAnnotation class]]) {
            CustomAnnotation *customAnnotation = (CustomAnnotation *) annotation;

            MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:@"CustomAnnotation"];

            if (annotationView == nil)
                annotationView = customAnnotation.annotationView;
            else
                annotationView.annotation = annotation;

            //Adding multiline subtitle code 

            UILabel *subTitlelbl = [[UILabel alloc]init];
            subTitlelbl.text = @"sri ganganagar this is my home twon.sri ganganagar this is my home twon.sri ganganagar this is my home twon.  ";

            annotationView.detailCalloutAccessoryView = subTitlelbl;

            NSLayoutConstraint *width = [NSLayoutConstraint constraintWithItem:subTitlelbl attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationLessThanOrEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:150];

             NSLayoutConstraint *height = [NSLayoutConstraint constraintWithItem:subTitlelbl attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationGreaterThanOrEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:0];
            [subTitlelbl setNumberOfLines:0];
            [subTitlelbl addConstraint:width];
            [subTitlelbl addConstraint:height];




            return annotationView;
        } else
            return nil;
    }