Objective-C ,ios,iphone开发基础:多个视图（view）之间的切换，以及视图之间传值。

所有的视图都继承自 UIViewController，都使用 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil;来初始化视图，所以一般初始化的数据或者变量都是在这个方法中。

首先建一个single view 工程，然后再添加一个view。

结构如图：

单击单开 cidpViewController.xib 文件，在视图上面拖放一个UIbutton 和一个 UILable，并且在cidpViewController.h文件中声明一个变量和一个方法，然后将UIbutton 和对应的方法连线， UILable和对应的变量连线，（这里要注意的是，必须将UIbutton的Touch up inside 和对应的方法连接 ）。

SecondViewController.xib同上：

关键代码如下：

#pragma mark 支持试图切换的方法
#pragma mark -
-(IBAction)btnPreClick:(id)sender{
    //实例化一个SecondViewController 对象
    SecondViewController* second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    //控制试图加载的样式，就是一些效果，有四种可以选择
    second.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
    //让实例化的试图对象加载在当前试图之上，
    [self presentModalViewController:second animated:YES];
    //页面传值。
    second.lblNext.text = lblPre.text;
    //释放开辟的空间，前提是将 arc关闭。
    [second release];
    
}


#pragma mark 试图消失的方法：
#pragma mark -
-(IBAction)btnBackClick:(id)sender{
    //让当前试图消失
    [self dismissModalViewControllerAnimated:YES];
}

整个代码如下：

// // cidpViewController.h

#import <UIKit/UIKit.h>
#import "SecondViewController.h"
@interface cidpViewController : UIViewController{
    
    IBOutlet UILabel* lblPre;
}
@property (nonatomic,retain) UILabel* lblPre;
-(IBAction)btnPreClick:(id)sender;
@end

// // cidpViewController.m 
#import "cidpViewController.h"

@implementation cidpViewController
@synthesize lblPre;
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

#pragma mark 支持试图切换的方法
#pragma mark -
-(IBAction)btnPreClick:(id)sender{
    //实例化一个SecondViewController 对象
    SecondViewController* second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    //控制试图加载的样式，就是一些效果，有四种可以选择
    second.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
    //让实例化的试图对象加载在当前试图之上，
    [self presentModalViewController:second animated:YES];
    //页面传值。
    second.lblNext.text = lblPre.text;
    //释放开辟的空间，前提是将 arc关闭。
    [second release];
    
}
@end

// // SecondViewController.h 
#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController{
    IBOutlet UILabel* lblNext;
    
}
@property (nonatomic ,retain) UILabel* lblNext;
-(IBAction)btnBackClick:(id)sender;
@end

// // SecondViewController.m 
#import "SecondViewController.h"

@implementation SecondViewController
@synthesize lblNext;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (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.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark 试图消失的方法：
#pragma mark -
-(IBAction)btnBackClick:(id)sender{
    //让当前试图消失
    [self dismissModalViewControllerAnimated:YES];
}

@end