动态修改NavigationBar背景色

第三方Git:

使用：

#import "UINavigationBar+Awesome.h"
#define NAVBAR_CHANGE_POINT 50

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.navigationController.navigationBar lt_setBackgroundColor:[UIColor clearColor]];
}
- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
    
    self.navigationController.navigationBar.tintColor = [UIColor whiteColor];
    
    
    //    从二级页面返回时，改变根据当前偏移量改变导航栏颜色。
    UIColor * color = [UIColor colorWithRed:100/255.0 green:100/255.0 blue:100/255.0 alpha:1];
    CGFloat offsetY = self.tableView.contentOffset.y;
    if (offsetY > NAVBAR_CHANGE_POINT) {
        CGFloat alpha = MIN(1, 1 - ((NAVBAR_CHANGE_POINT + 64 - offsetY) / 64));
        [self.navigationController.navigationBar lt_setBackgroundColor:[color colorWithAlphaComponent:alpha]];
    } else {
        [self.navigationController.navigationBar lt_setBackgroundColor:[color colorWithAlphaComponent:0]];
    }
   
    self.navigationController.navigationBar.barStyle = UIBarStyleBlack;
    self.navigationController.navigationBar.tintColor = [UIColor whiteColor];
    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleLightContent;
    
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    
    //  到二级页面导航栏恢复默认设置
    [self.navigationController.navigationBar lt_reset];
    
    self.navigationController.navigationBar.barStyle = UIBarStyleDefault;
    self.navigationController.navigationBar.tintColor = nil;
    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleDefault;
    
}