在UIImageView iOS后面添加渐变层

Question

我正在尝试在透明图像后面添加渐变。我在地图上做了leftCallOutAccessoryView但是无论我尝试什么，渐变层总是显示在imageView上方并希望它出现在它后面

继承我的MKAnnotationView代码，这是一个叫做pinView的ivar

pinView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

UIImageView *profileIconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Profile.png"]];
pinView.leftCalloutAccessoryView = profileIconView;

CAGradientLayer *backgroundLayer = [CAGradientLayer layer];
backgroundLayer.frame = CGRectMake(0, 0, 30, 30);
backgroundLayer.cornerRadius = 2;
backgroundLayer.borderWidth = 1;
backgroundLayer.borderColor = [UIColor whiteColor].CGColor;
backgroundLayer.colors = [NSArray arrayWithObjects:(id)[[sharedManager cellGradientEnd] CGColor], (id)[[sharedManager cellGradientStart] CGColor], nil];
[profileIconView.layer insertSublayer:backgroundLayer atIndex:0];

Answer 1

我设法使用下面的方法来解决它，简而言之，我创建了一个空视图，然后将imageView作为子视图添加到视图中，现在它们都很甜蜜！：

UIView *view = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];
UIImageView *profileIconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Profile.png"]];
pinView.leftCalloutAccessoryView = view;

CAGradientLayer *backgroundLayer = [CAGradientLayer layer];
backgroundLayer.frame = view.bounds;
backgroundLayer.cornerRadius = 2;
backgroundLayer.borderWidth = 1;
backgroundLayer.borderColor = [UIColor whiteColor].CGColor;
backgroundLayer.colors = [NSArray arrayWithObjects:(id)[[sharedManager cellGradientEnd] CGColor], (id)[[sharedManager cellGradientStart] CGColor], nil];
[pinView.leftCalloutAccessoryView.layer insertSublayer:backgroundLayer atIndex:0];
[view addSubview:profileIconView];