Ios: Modify the background color of NavigationController

Ios: Modify the background color of NavigationController

 

 

During ios development, we often need to modify the background color of NavigationController. When using [self. navigationController. when navigationBar setBackgroundColor: [UIColor redColor], the running result cannot be changed to Beijing color:

 

A new method is provided to solve this problem:

Write a NavigationBar to write a category:

 

@ Interface UINavigationBar (BackgroundColor)

 

// Set the background color of navigationBar

 

-(Void) lt_setBackgroundColor :( UIColor *) backgroundColor;

@ End

 

 

@ Implementation UINavigationBar (BackgroundColor)

 

Static char overlayKey;

 

-(UIView *) overlay

{

Return objc_getAssociatedObject (self, & overlayKey );

}

 

-(Void) setOverlay :( UIView *) overlay

{

Objc_setAssociatedObject (self, & overlayKey, overlay, OBJC_ASSOCIATION_RETAIN_NONATOMIC );

}

 

-(Void) lt_setBackgroundColor :( UIColor *) backgroundColor

{

If (! Self. overlay ){

[Self setBackgroundImage: [UIImage new] forBarMetrics: UIBarMetricsDefault];

[Self setShadowImage: [UIImage new]; // insert an overlay into the view hierarchy

Self. overlay = [[UIView alloc] initWithFrame: CGRectMake (0,-20, [UIScreen mainScreen]. bounds. size. width, 64)];

[Self insertSubview: self. overlay atIndex: 0];

}

Self. overlay. backgroundColor = backgroundColor;

}

@ End

 

 

Note: When Using objc_getAssociatedObject, You need to introduce the header file # import