UINavigationController详解与使用(三)ToolBar

UINavigationController详解与使用(二)页面切换和segmentedController 接上篇，我们接着讲Navigation 的Toolbar。

运行效果图：

第一个界面
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[img]http://dl.iteye.com/upload/attachment/0078/5821/58b4cf25-18d3-3caa-a8c6-13ee0cb968bc.jpg[/img]
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第二个界面
[img]
[img]http://dl.iteye.com/upload/attachment/0078/5823/66d3ddfd-5e52-3119-b6ef-ffb68e0c367c.jpg[/img]
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第三个界面
[img]
[img]http://dl.iteye.com/upload/attachment/0078/5825/690d87de-0cfb-3ed7-98f5-157d44447a62.jpg[/img]
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1、显示Toolbar
在RootViewController.m的- (void)viewDidLoad方法中添加代码，这样Toobar就显示出来了。

[self.navigationController  setToolbarHidden:NO animated:YES];

2、在ToolBar上添加UIBarButtonItem
新建几个UIBarButtonItem，然后以数组的形式添加到Toolbar中

UIBarButtonItem *one = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil];
    UIBarButtonItem *two = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemBookmarks target:nil action:nil];
    UIBarButtonItem *three = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:nil action:nil];
    UIBarButtonItem *four = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:nil action:nil];
    UIBarButtonItem *flexItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    [self setToolbarItems:[NSArray arrayWithObjects:flexItem, one, flexItem, two, flexItem, three, flexItem, four, flexItem, nil]];

注意：用 [self.navigationController.toolbar setItems:(NSArray *) animated:<#(BOOL)#>]这个方法添加item是不起效果的。下面我动态自己添加Toolbar时，这个才起效果。

3、动态添加Toolbar
我们在SecondView添加动态的Toolbar。
在SecondViewController.h添加

#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController
{
    UIToolbar *toolBar;
}
@end

在SecondViewController.m添加:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.navigationController  setToolbarHidden:YES animated:YES];

    UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSearch target:self action:@selector(gotoThridView:)];
    toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0.0, self.view.frame.size.height - toolBar.frame.size.height - 44.0, self.view.frame.size.width, 44.0)];
    [toolBar setBarStyle:UIBarStyleDefault];
    toolBar.autoresizingMask = UIViewAutoresizingFlexibleTopMargin;
    [toolBar setItems:[NSArray arrayWithObject:addButton]];
    [self.view addSubview:toolBar];

    // Do any additional setup after loading the view from its nib.
}

先把RootView时显示的Toobar隐藏

[self.navigationController setToolbarHidden:YESanimated:YES];然后把新建的Toolbar添加的SecondView中，并为Toobar设置了一个Item.

[toolBarsetItems:[NSArrayarrayWithObject:addButton]];

4、新建ThridView，从SecondView跳转到

Commad+N新建一个ThridViewController，

这个addButton跳转到ThridView

-(void)gotoThridView:(id)sender
{
    ThridViewController *thridView = [[ThridViewController alloc] init];
    [self.navigationController pushViewController:thridView animated:YES];
    thridView.title = @"Thrid View";

}

动态添加的时候，当从第二个View返回rootView的时候，rootView里面的toolBar消失了，该怎么办呢？
在RootViewController.m中添加该句，就可以了

-(void)viewWillAppear:(BOOL)animated{
[self.navigationController setToolbarHidden:NO animated:YES];
}

如何给UIToolBar 添加 多个UIBarButtonItem . 在写一遍：

//首先需要创建一个NSMutableArray 
NSMutableArray *buttons=[[NSMutableArray  alloc]initWithCapacity:3];
[buttons  autorelease];

//创建一个 UIBarButtonItem 系统刷新按钮  并且加入到Array中
UIBarButtonItem   *freshButton=[[UIBarButtonItem alloc]  initWithBarButtonSystemItem: UIBarButtonSystemItemRefresh     target:self   action:@selector(OnrefreshMap:)];
[buttons addObject:freshButton];
[freshButton release];
//创建一个空格 ，加入到array，用来将下面加入的按钮按照右边对齐
UIBarButtonItem   *SpaceButton=[[UIBarButtonItem alloc]  initWithBarButtonSystemItem: UIBarButtonSystemItemFlexibleSpace     target:nil   action:nil];
[buttons addObject:SpaceButton];
[SpaceButton release];

//创建一个 系统 搜索按钮，加入到array，放到右边
UIBarButtonItem   *searchSelfButton=[[UIBarButtonItem alloc]  initWithBarButtonSystemItem: UIBarButtonSystemItemSearch     target:self   action:@selector(OnFindSelf:)];
[buttons addObject:searchSelfButton];
[searchSelfButton release];

//最后，将array 设置给toolbar
[toolbar setItems:buttons animated:YES];
[toolbar  sizeToFit];