127

我希望我的应用程序中的 UINavigationBar 完全透明，并与它正下方的视图控制器齐平。但是，我能找到的唯一代码使其半透明但不透明。我知道这可以在 iOS 7 中完成，因为它在笔记应用程序中使用。我的问题是，他们用来做这件事的代码是什么？

4

8 回答 8

296

从这个答案

[self.navigationController.navigationBar setBackgroundImage:[UIImage new]
                     forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = [UIImage new];
self.navigationController.navigationBar.translucent = YES;
self.navigationController.view.backgroundColor = [UIColor clearColor];
self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];

此外，正如 Josh 在评论中所建议的，将栏恢复为默认值：

[self.navigationController.navigationBar setBackgroundImage:nil
                     forBarMetrics:UIBarMetricsDefault];
于 2013-10-11T16:41:57.603 回答
79

对于 Swift3 和 Swift4

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.isTranslucent = true

对于 Swift2.2

 self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)
 self.navigationController?.navigationBar.shadowImage = UIImage()
 self.navigationController?.navigationBar.translucent = true

对于 Objective-C

[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = [UIImage new];
self.navigationController.navigationBar.translucent = YES;
于 2015-08-11T08:04:01.597 回答
39

作为 Objective-C 类别的自包含解决方案：

UINavigationController+TransparentNavigationController.h

@interface UINavigationController (TransparentNavigationController)
- (void)presentTransparentNavigationBar;
- (void)hideTransparentNavigationBar;
@end

UINavigationController+TransparentNavigationController.m

#import "UINavigationController+TransparentNavigationController.h"

@implementation UINavigationController (TransparentNavigationController)

- (void)presentTransparentNavigationBar
{
  [self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
  [self.navigationBar setTranslucent:YES];
  [self.navigationBar setShadowImage:[UIImage new]];
  [self setNavigationBarHidden:NO animated:YES];
}

- (void)hideTransparentNavigationBar
{
  [self setNavigationBarHidden:YES animated:NO];
  [self.navigationBar setBackgroundImage:[[UINavigationBar appearance] backgroundImageForBarMetrics:UIBarMetricsDefault] forBarMetrics:UIBarMetricsDefault];
  [self.navigationBar setTranslucent:[[UINavigationBar appearance] isTranslucent]];
  [self.navigationBar setShadowImage:[[UINavigationBar appearance] shadowImage]];
}

@end

现在，您可以导入您的类别UIViewController并调用导航控制器上的方法 - 例如：

#import "UINavigationController+TransparentNavigationController.h"

- (void)viewWillAppear:(BOOL)animated
{
  [super viewWillAppear:animated];
  [self.navigationController presentTransparentNavigationBar];
}

- (void)viewWillDisappear:(BOOL)animated
{
  [super viewWillDisappear:animated];
  [self.navigationController hideTransparentNavigationBar];
}

以及Swift中的类似解决方案：

import Foundation
import UIKit

extension UINavigationController {

  public func presentTransparentNavigationBar() {
    navigationBar.setBackgroundImage(UIImage(), forBarMetrics:UIBarMetrics.Default)
    navigationBar.translucent = true
    navigationBar.shadowImage = UIImage()
    setNavigationBarHidden(false, animated:true)
  }

  public func hideTransparentNavigationBar() {
    setNavigationBarHidden(true, animated:false)
    navigationBar.setBackgroundImage(UINavigationBar.appearance().backgroundImageForBarMetrics(UIBarMetrics.Default), forBarMetrics:UIBarMetrics.Default)
    navigationBar.translucent = UINavigationBar.appearance().translucent
    navigationBar.shadowImage = UINavigationBar.appearance().shadowImage
  }
}
于 2014-12-22T22:26:28.640 回答
15

艾伦忘记了一行

self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];

所以我有：

[self.navigationController.navigationBar setTranslucent:YES];
self.navigationController.view.backgroundColor = [UIColor clearColor];
[self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = [[UIImage alloc] init];
self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
于 2014-10-21T16:07:46.763 回答
5

@Zorayr 的最佳答案修改为 Swift 3 ：

import Foundation
import UIKit

extension UINavigationController {

    public func presentTransparentNavigationBar() {
        navigationBar.setBackgroundImage(UIImage(), for:.default)
        navigationBar.isTranslucent = true
        navigationBar.shadowImage = UIImage()
        setNavigationBarHidden(false, animated:true)
    }

    public func hideTransparentNavigationBar() {
        setNavigationBarHidden(true, animated:false)
        navigationBar.setBackgroundImage(UINavigationBar.appearance().backgroundImage(for: UIBarMetrics.default), for:.default)
        navigationBar.isTranslucent = UINavigationBar.appearance().isTranslucent
        navigationBar.shadowImage = UINavigationBar.appearance().shadowImage
    }
}
于 2017-02-05T01:43:57.967 回答
3

斯威夫特 4.2 和 iOS 12

事实证明，您真正需要的只是下面的代码。当您将其放入viewDidLoad().

// removes line at bottom of navigation bar
navigationController?.navigationBar.shadowImage = UIImage()

// makes navigation bar completely transparent
navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
navigationController?.navigationBar.isTranslucent = true
于 2018-10-09T17:53:47.433 回答
-3

使用UINavigationBar+Addition pod，然后简单地调用：

UINavigationBar *navigationBar = self.navigationController.navigationBar;
[navigationBar makeTransparent];
于 2015-09-23T14:49:50.893 回答
-4

[(UIView*)[self.navigationController.navigationBar.subviews objectAtIndex:0] setAlpha:0.0f];

那一行似乎对我很有效

于 2016-04-05T08:17:23.200 回答