ios学习：页面跳转（present）

//
//  TWFXSecondViewController.m
//  DemoMultiView
//
//  Created by Lion User on 12-12-24.
//  Copyright (c) 2012年 Lion User. All rights reserved.
//

#import "TWFXSecondViewController.h"
#import "TWFXThirdViewController.h"

@interface TWFXSecondViewController ()

@end

@implementation TWFXSecondViewController
@synthesize thirdViewController;

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

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

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
 多视图切换,如果是从A视图跳转到B视图,那么A表示当前视图,B表示将要跳转到视图
 多视图跳转可以理解为有两部分:从A跳到B, B 返回 A.注意,是返回,不是重新发起跳转
 这里是第二阶段:从B返回A

 self.presentingViewController 在跳转发生后有效,表示B试图的上一个视图,在这里为A视图
 self.presentedViewController 在跳转发生后有效,表示B视图的下一个视图,在这里为nil,以为并没有发生跳转
 self.parentViewController表示B的父试图,也为nil
 */
-(IBAction)btnClicGoBack:(UIButton *)sender{

    void(^task)() = ^{

        NSLog(@"2self: %@",self);
        NSLog(@"2back ed%@",self.presentedViewController);
        NSLog(@"2back ing%@",self.presentingViewController);
        //  NSLog(@"back par%@",self.parentViewController);
        printf("\n\n");

    };

   // task();

    //跳转完成后调用completion,此时,当前视图已被销毁,self.presentedViewController self.presentingViewController都为nil
    [self dismissViewControllerAnimated:YES completion:nil];

    task();//此时,当前视图还没被销毁,self.presentingViewController 表示上一个视图

}

- (IBAction)btnClickTraToFirst:(UIButton *)sender {
}

/*
 这里表示从B视图跳到C视图
 */
- (IBAction)btnClickTra:(UIButton *)sender {

    if (self.thirdViewController == nil) {

        /*
         最常用的初始化方法
         nibName 表示xib文件的名字,不包括扩展名
         nibBundle 制定在那个文件束中搜索制定的nib文件,如在主目录下,则可以直接用nil
         */
        self.thirdViewController = [[[TWFXThirdViewController alloc] initWithNibName:@"TWFXThirdViewController" bundle:nil]autorelease] ;

    }

    //视图切换的动画效果
    self.thirdViewController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

    void(^task)() = ^{

        NSLog(@"2self: %@",self);
        NSLog(@"2go ed%@",self.presentedViewController);
        NSLog(@"2go ing%@",self.presentingViewController);
        //  NSLog(@"go par%@",self.parentViewController);
        printf("\n\n");
    };
    // task = ^(){};

    // task();//跳转前没意义

    /*
     completion是一个回调,当 当前视图(这里是TWFXViewController) 的viewDidDisear调用后,该回调被调用
     self.presentingViewController(表示上一个视图)为A视图
     self.presentedViewController(表示下一个试图)为C视图
     */
    [self presentViewController:thirdViewController animated:YES completion:task];

}

@end