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