我正在尝试将添加到MKMapView的图像旋转为注释。
这是代码：
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation: (id<MKAnnotation>)annotation
{
if (! [annotation isKindOfClass:[IGAMapAnnotation class]])
{
//return default view if annotation is NOT of type IGAMapAnnotation...
return nil;
}
MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:@"IGAMapAnnotation"];
if (annotationView == nil)
{
annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"IGAMapAnnotation"];
annotationView.enabled = YES;
annotationView.canShowCallout = YES;
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
}
else
{
annotationView.annotation = annotation;
}
IGAMapAnnotation *myLocation = (IGAMapAnnotation *) annotation;
// THIS IS IT!
if ([myLocation.type isEqual: @"PLANE"]) {
UIImage *planeImage = [UIImage imageNamed:@"planetracked.png"];
UIImageView *planeImageView = [[UIImageView alloc]initWithImage:planeImage];
planeImageView.transform = CGAffineTransformMakeRotation(M_PI_2);
annotationView.image = planeImageView;
}
return annotationView;
}
它显然给了我一个错误，因为annotationView.image应该分配一个图像而不是UIImageView。我尝试过各种旋转图像的方法，例如：
- (UIImage *)rotateImage:(UIImage *)image onDegrees:(NSString *)heading {
double angle = [heading doubleValue];
CGSize s = {image.size.width, image.size.height};
UIGraphicsBeginImageContext(s);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, 0,image.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextRotateCTM(ctx, 2*M_PI*angle/360);
CGContextDrawImage(ctx,CGRectMake(0,0,image.size.width, image.size.height),image.CGImage);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
它们也不起作用 - 地图上没有图像。
任何人都知道如何在MKMapView上旋转注释图像？
百万，谢谢！答案 0 :(得分：4)
而不是：
annotationView.image = planeImageView;
这绝对是错误的（image属性是UIImage而planeImageView是UIImageView），使用addSubview:添加UIImageView }到注释视图（保留视图的image属性nil并且未使用）。
但是，您还需要进行一些其他调整，以便：
要做这些事情，请增加两个视图的帧大小以考虑旋转可能的最大宽度（假设图像是正方形，这是原始宽度的2倍的平方根）并设置图像视图＆＃39 ; s contentMode到＆＃34;中心＆＃34;因此，图像不会因这些帧大小的变化而失真。
另一个重要问题是，如果你IGAMapAnnotation的{{1}}不是＆＃34;飞机＆＃34;，那么它们将是：
type，也未将任何子视图添加到注释视图中），或者，为了避免两种类型的注释（＆＃34;平面＆＃34; /＆＃34;而不是平面＆＃34;）重复使用彼此的视图，我建议使用不同的重复使用每个类型的标识符（不每个注释）并对视图应用特定于类型的更改。
修订后的image方法如下所示：
viewForAnnotation顺便说一下，使用-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if (! [annotation isKindOfClass:[IGAMapAnnotation class]])
{
//return default view if annotation is NOT of type IGAMapAnnotation...
return nil;
}
IGAMapAnnotation *myLocation = (IGAMapAnnotation *)annotation;
BOOL typeIsPlane = [myLocation.type isEqualToString:@"PLANE"];
int planeImageViewTag = 42;
NSString *reuseId = typeIsPlane ? @"IGAMapAnnotationPlane" : @"IGAMapAnnotationOther";
MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
if (annotationView == nil)
{
annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
annotationView.enabled = YES;
annotationView.canShowCallout = YES;
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
if (typeIsPlane)
{
//Here, just add the image view to the annotation view with no
//rotation. Only want to add the image view to the annotation
//view ONCE when the annotation view is initially created. If
//view is dequeued, it will already have an image view and we
//just update its rotation.
UIImage *planeImage = [UIImage imageNamed:@"planetracked.png"];
UIImageView *planeImageView = [[UIImageView alloc] initWithImage:planeImage];
planeImageView.tag = planeImageViewTag;
planeImageView.contentMode = UIViewContentModeCenter;
[annotationView addSubview: planeImageView];
CGRect avFrame = annotationView.frame;
//"1.5" on next line is the square root of 2 rounded up a bit.
avFrame.size = CGSizeMake(planeImage.size.width*1.5,
planeImage.size.height*1.5);
annotationView.frame = avFrame;
planeImageView.frame = annotationView.frame;
}
else
{
//If this IGAMapAnnotation is not a "plane",
//show some other default image.
//(Or, you could return nil to show a default red pin.)
annotationView.image = [UIImage imageNamed:@"NotAPlane.png"];
//May or may not need to set centerOffset.
//Either remove or adjust 0,0 as needed to
//center the image on the coordinates.
annotationView.centerOffset = CGPointMake(0, 0);
}
}
else
{
annotationView.annotation = annotation;
}
//At this point, we have a new or dequeued annotation view ready
//and pointing to the current annotation.
//Now make any annotation-specific changes to the view...
if (typeIsPlane)
{
UIImageView *planeImageView = (UIImageView *)[annotationView viewWithTag:planeImageViewTag];
planeImageView.transform = CGAffineTransformMakeRotation(M_PI_2);
//Replace M_PI_2 with rotation specific to this annotation's heading.
}
return annotationView;
}
代替isEqualToString:和isEqual: s。
NSString问题，removeAnnotations:必须包含地图上注释的新实例。要删除现有注释，您必须提供对最初添加的完全相同对象的引用。
如果您要始终删除所有注释并重新添加所有注释，则可以执行mapLocations。
如果您只删除某些注释，则需要保留对最初添加的注释的引用，或者遍历地图视图的[self.mapView removeAnnotations:self.mapView.annotations];数组并识别哪些应删除（保留一个临时annotations作为＆＃34;注释列表以删除＆＃34;）然后使用该注释列表调用NSMutableArray以删除。
答案 1 :(得分：1)
以下似乎有效。百万感谢安娜没有他们不会拥有的人！
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
if (! [annotation isKindOfClass:[IGAMapAnnotation class]]) {
return nil;
}
IGAMapAnnotation *myLocation = (IGAMapAnnotation *) annotation;
BOOL typeIsPlane = [myLocation.navaidType isEqualToString:@"PLANE"];
BOOL typeIsOne = [myLocation.navaidType isEqualToString:@"ONE"];
BOOL typeIsTwo = [myLocation.navaidType isEqualToString:@"TWO"];
BOOL typeIsThree = [myLocation.navaidType isEqualToString:@"THREE"];
int planeImageViewTag = 42;
NSString *reuseId;
if (typeIsPlane)
reuseId = @"IGAMapAnnotationPlane";
else if (typeIsOne)
reuseId = @"IGAMapAnnotationOne";
else if (typeIsTwo)
reuseId = @"IGAMapAnnotationTwo";
else if (typeIsThree)
reuseId = @"IGAMapAnnotationThree";
else
reuseId = @"IGAMapAnnotationOther";
MKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
if (annotationView == nil)
{
annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
annotationView.enabled = YES;
annotationView.canShowCallout = YES;
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
if (typeIsPlane)
{
UIImage *planeImage = [UIImage imageNamed:@"mapPLANE.png"];
UIImageView *planeImageView = [[UIImageView alloc] initWithImage:planeImage];
planeImageView.tag = planeImageViewTag;
planeImageView.contentMode = UIViewContentModeCenter;
[annotationView addSubview: planeImageView];
CGRect avFrame = annotationView.frame;
//"1.5" on next line is the square root of 2 rounded up a bit.
avFrame.size = CGSizeMake(planeImage.size.width*1.5,
planeImage.size.height*1.5);
annotationView.frame = avFrame;
planeImageView.frame = annotationView.frame;
}
else if (typeIsOne)
{
annotationView.image = [UIImage imageNamed:@"one.png"];
annotationView.centerOffset = CGPointMake(0, 0);
}
else if (typeIsTwo)
{
annotationView.image = [UIImage imageNamed:@"two.png"];
annotationView.centerOffset = CGPointMake(0, 0);
}
else if (typeIsThree)
{
annotationView.image = [UIImage imageNamed:@"three.png"];
annotationView.centerOffset = CGPointMake(0, 0);
}
else
return nil;
}
else
{
annotationView.annotation = annotation;
}
if (typeIsPlane)
{
// Convert current heading string to double
double headingDouble = [currentHeading doubleValue];
UIImageView *planeImageView = (UIImageView *)[annotationView viewWithTag:planeImageViewTag];
planeImageView.transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(headingDouble));
}
return annotationView;
}