问题描述

MKAnnotation显示问题

MKMapView 中有一个标志针
点击标记针时可以看见标题和副标题，怎么样不需要点击标记让标题自动显示。
代码如下：

 self.mapView = [[[MKMapView alloc]init] autorelease];    mapView.frame = self.view.bounds;    mapView.delegate = self;    [self.view addSubview:mapView];    location = CLLocationCoordinate2DMake(lattitude longitude);    MKCoordinateRegion region = self.mapView.region;    region.center = location;    region.span.longitudeDelta = kSpan;    region.span.latitudeDelta = kSpan;    [self.mapView setRegion:region animated:YES];    CustomMapAnnotation *newAnnotation = [[CustomMapAnnotation alloc] init];    newAnnotation.title = @""Title"";    newAnnotation.subtitle = @""Subtitle"";    newAnnotation.accessibilityTraits = UIAccessibilityTraitButton;    newAnnotation.coordinate = location;    annotation = newAnnotation;    [mapView addAnnotation:annotation];    [newAnnotation release];- (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>) annotationDel{    MKPinAnnotationView *pinView = nil;    static NSString *defaultPinID = @""mapPin"";    pinView = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];    if (pinView == nil)        pinView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotationDel reuseIdentifier:defaultPinID] autorelease];    pinView.pinColor = MKPinAnnotationColorRed;    pinView.canShowCallout = YES;    pinView.animatesDrop = YES;    [pinView setSelected:YES];    UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];    [rightButton addTarget:self action:@selector(detailButtonPressed:) forControlEvents:UIControlEventTouchUpInside];    pinView.rightCalloutAccessoryView = rightButton;    return pinView;}

解决方案

使用MKMapView的selectAnnotation:animated 方法

[mapView selectAnnotation:YorAnnotation animated:YES];