自定义导航栏--将NavigationBar设置透明

 1 - (void) navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
 2     // 如果进入的是当前视图控制器
 3     if (viewController == self) {
 4         // 背景设置为黑色
 5         self.navigationController.navigationBar.tintColor = [UIColor colorWithRed:0.000 green:0.000 blue:0.000 alpha:1.000];
 6         // 透明度设置为0.3
 7         self.navigationController.navigationBar.alpha = 0.300;
 8         // 设置为半透明
 9         self.navigationController.navigationBar.translucent = YES; 
10     } else {
11    // 进入其他视图控制器
12         self.navigationController.navigationBar.alpha = 1;
13         // 背景颜色设置为系统默认颜色   
14         self.navigationController.navigationBar.tintColor = nil;
15         self.navigationController.navigationBar.translucent = NO; 
16     }
17 }