IOS开发笔记(六)---对iOS多视图开发的初步了解

今天看了一下iOS开发中多个视图的应用.

iOS下包含了几种不同种类的视图类型和controller:比如Tab bar,Navigation bar,Tool bar等.也可以自定义自己的视图的controller

程序中主窗口的视图控制器我们成为root controller,由它负责不同视图的切换等功能.

由root controller负责的视图都有自己的controller和delegate,比如一个tab bar,当用户在tab bar上点击的时候,是由tab bar的controller负责处理,而当用户在内容界面点击的时候,是由内容视图的controller负责处理的.

书中的例子很简单,点击tab bar中的按扭,在两个背景颜色(一蓝一黄)的视图中切换,两个视图中各有一个button

书中的例子建立的步骤如下:

1.建立一个Window base application,没有vIEw controller,只有一个window

2.添加视图文件

2.1 新建文件,选择cocoa touch下的UIVIEwController subclass 不使用xib文件(书中这里是xcode4.2以前的版本) 保存为SwitchVIEwController.h 和 SwitchVIEwController.m.这就是root controller

2.2 按照步骤2.1,创建蓝,黄背景视图的类文件 BlueVIEwController & YellowVIEwController

3.添加xib文件

3.1 选择cocoa touch下user interface下的VIEw XIB的文件

3.2 新建两个视图的xib文件,BlueVIEw.xib & YellowVIEw.xib

4.在AppDelegate中添加一个IBOutlet,

@property (nonatomic,retain) IBOutlet SwitchVIEwController   *switchVIEwController;

5.为了将主视图SwitchVIEwController和Window关联,需要使用addSubvIEw,添加了以下代码:

#import "VIEw_SwitcherAppDelegate.h" 
#import "SwitchVIEwController.h" 
@implementation VIEw_SwitcherAppDelegate 
@synthesize window; 
@synthesize switchVIEwController; 
- (voID) application:(UIApplication *)application 
dIDFinishLaunchingWithOptions:(NSDictionary *)launchOptions{ 
    // OverrIDe point for customization after application launch 
   [self.window addSubvIEw:switchVIEwController.vIEw]; 
    [self.window makeKeyAndVisible]; 
    return YES; //注:书中代码这样写的,返回YES 但是函数类型是voID.经查SDK,发现函数类型是BOol
} 
- (voID)dealloc { 
    [window release]; 
   [switchVIEwController release]; 
    [super dealloc]; 
}

6. 为了切换两个vIEw,我们在SwitchVIEwController里添加两个VIEw的指针,不定义IBOutlet,同时定义方法switchVIEws

#import <UIKit/UIKit.h> 
@class YellowVIEwController; 
@class BlueVIEwController; 
@interface SwitchVIEwController : UIVIEwController { 
} 
@property (retain,nonatomic) YellowVIEwController *yellowVIEwController; 
@property (retain,nonatomic) BlueVIEwController *blueVIEwController; 
- (IBAction)switchVIEws:(ID)sender; 
@end

7.代码架构好了,开始在IB中 *** 作

7.1 在library中拖动一个VIEw Controller到Window上面

7.2 该VIEw是UIVIEwController,在IDentity Inspector中修改类名为UIVIEwController

7.3 新建Toolbar的VIEw,拖放一个VIEw到7.1添加的VIEw上面,替换原有的VIEw(注:为何是替换呢?)

7.4 拖动一个Toolbar到7.3新建的VIEw中,选中Toolbar后,点击button,链接到SwitchVIEwController的方法switchVIEw中

8. 在IB中将AppDelegate中的IBOutlet switchVIEwController与类SwitchVIEwController链接

9. 修改SwitchVIEwController.m

主要就是从Nib加载VIEwController,不用的释放Controller

刚开始只加载BlueVIEw,因为YellowVIEw可能用户不会选择,等到切换的时候才加载(Lazy Loading)

#import "SwitchVIEwController.h" 
#import "YellowVIEwController.h" 
#import "BlueVIEwController.h" 
@implementation SwitchVIEwController 
@synthesize yellowVIEwController; 
@synthesize blueVIEwController; 
- (voID)vIEwDIDLoad 
{ 
    BlueVIEwController *blueController = [[BlueVIEwController alloc] 
              initWithNibname:@"BlueVIEw" bundle:nil]; 
    self.blueVIEwController = blueController; 
   [self.vIEw insertSubvIEw:blueController.vIEw atIndex:0]; 
    [blueController release]; 
    [super vIEwDIDLoad]; 
} 
- (IBAction)switchVIEws:(ID)sender 
{ 
    if (self.yellowVIEwController.vIEw.supervIEw == nil) 
   { 
        if (self.yellowVIEwController == nil) 
        { 
            YellowVIEwController *yellowController = 
           [[YellowVIEwController alloc] initWithNibname:@"YellowVIEw" 
                                                   bundle:nil]; 
            self.yellowVIEwController = yellowController;

            [yellowController release]; 
        } 
        [blueVIEwController.vIEw removeFromSupervIEw]; 
        [self.vIEw insertSubvIEw:yellowVIEwController.vIEw atIndex:0]; 
   } 
   else 
   { 
      if (self.blueVIEwController == nil) 
      { 
          BlueVIEwController *blueController = 
          [[BlueVIEwController alloc] initWithNibname:@"BlueVIEw" 
                                               bundle:nil]; 
          self.blueVIEwController = blueController; 
          [blueController release]; 
      } 
      [yellowVIEwController.vIEw removeFromSupervIEw]; 
      [self.vIEw insertSubvIEw:blueVIEwController.vIEw atIndex:0]; 
   } 
}

- (voID)dIDReceiveMemoryWarning { 
    // Releases the vIEw if it doesn't have a supervIEw 
    [super dIDReceiveMemoryWarning]; 
    // Release any cached data,images,etc,that aren't in use 
    if (self.blueVIEwController.vIEw.supervIEw == nil) 
        self.blueVIEwController = nil; 
    else 
       self.yellowVIEwController = nil; 
}

- (voID)dealloc { 
    [yellowVIEwController release]; 
    [blueVIEwController release]; 
    [super dealloc]; 
} 
@end

10.完善两个内容视图,添加button,d出不同的内容提示.

#import <UIKit/UIKit.h> 
@interface BlueVIEwController : UIVIEwController { 
} 
- (IBAction)bluebuttonpressed; 
@end

在实现中加入UIAlertVIEw即可.(略去)

打开BlueVIEw.nib,在Indentity Inspector中选择class name为BlueVIEwController,表明从nib从BlueVIEwController

然后修改VIEw的背景色,更改VIEw的位置在属性页的

Simulated User Interface Elements选项下

11.加入视图切换动画

- (IBAction)switchVIEws:(ID)sender 
{ 
    [UIVIEw beginAnimations:@"VIEw Flip" context:nil]; 
    [UIVIEw setAnimationDuration:1.25]; 
    [UIVIEw setAnimationCurve:UIVIEwAnimationCurveEaseInOut];

.....

if(..)

{

        [UIVIEw setAnimationTransition: 
         uiviewanimationtransitionFlipFromright 
                               forVIEw:self.vIEw cache:YES]; 
        [blueVIEwController vIEwWillAppear:YES]; 
        [yellowVIEwController vIEwWilldisappear:YES];

        … …

}

[UIVIEw commitAnimations];

}