Action Sheet就像Windows中的 “确定-取消”对话框一样，用于强制用户进行选择。当用户将要进行的操作具有一定危险时，常常使用Action Sheet对用户进行危险提示，这样，用户有机会进行取消操作。

Alert相当于Windows中的Messagebox，跟Action Sheet也是类似的。不同的是，Alert可以只有一个选择项，而Action Sheet却至少要两个选项。

1.创建一个新工程叫ActionSheetDemo； File->New->Project ->single View Application -> next 

2.因为用到了ActionSheet和Alert委托方法，把ActionSheet和Alert协议添加上，在声明下两个对象

#import <UIKit/UIKit.h>  @interface ASDViewController : UIViewController<UIAlertViewDelegate,UIActionSheetDelegate> {      UIActionSheet *actionSheet;     UIAlertView *alert ; }  -(void)buttonClicked:(id)sender; @end

3.ViewDidLod中代码基本都加注释了，直接贴上代码

- (void)viewDidLoad {     [super viewDidLoad]; 	// Do any additional setup after loading the view, typically from a nib.     CGRect frame = CGRectMake(50, 100, 200, 70);          UIButton *myButon = [UIButton buttonWithType:UIButtonTypeRoundedRect];          myButon.frame = frame; //  设置视图标题     [myButon setTitle:@"测试ActionSheet" forState:UIControlStateNormal]; //    [myButon setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];//设置Button没有被选择的时候的字体颜色,选中后就变成默认的蓝色字体     myButon.titleLabel.textColor = [UIColor blackColor];//也是字体颜色设置，和上没方法一样     [myButon setBackgroundColor:[UIColor clearColor]];//背景色设置 //    myButon.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;//button标题对齐方式，默认居中 //    给myButton添加一个事件buttonClicked     [myButon addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside]; //把按钮添加到view视图上     [self.view addSubview:myButon];           /*    //看博客时，以前没接触这个进度条控件，做测试用，搁着看的 http://www.cocoachina.com/iphonedev/toolthain/2011/1223/3778.html        UIProgressView *progressView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];     progressView.frame = CGRectMake(20, 300, 200, 30);     [alert addSubview:progressView];  */      }

4.Button点击事件，

-(void)buttonClicked:(id)sender {     UIAlertView *alerttest = [[UIAlertView alloc] initWithTitle:@"提示"                                                     message:@"你点击了测试ActionSheet这个按钮" delegate:self                                           cancelButtonTitle:@"嗯嗯 了解"                                           otherButtonTitles:@"弹出ActionSheet吧",@"无所谓",@"有所谓", nil];     [alerttest addButtonWithTitle:@"不发表意见"];//可以在Alrt上再添加一个Button     alert=alerttest;          [alert show];      }

//根据被点击按钮索引处理点击事件 -(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {   /********************************************************************************************    本想试试发挥下switch()的左右，可是在buttonIdex==2的时候，想加入一个Actionsheet，结果报错，说case 是保护数据，        ********************************************************************************************     switch (buttonIndex) {         case 0:             NSLog(@"取消按钮");             break;                          case 1:             NSLog(@"弹出ActionSheet吧");                         break;                          case 2:             NSLog(@"有所谓了");             break;                          case 3:             NSLog(@"无所谓了");             break;                          case 4:             NSLog(@"不发表意见");             break;                     default:             break;       }    ********************************************************************************************/     if (buttonIndex == 0) {         NSLog(@"取消按钮");     }     else if (buttonIndex == 1) {         UIActionSheet *sheet = [[UIActionSheet alloc] initWithTitle:@"操作选项" delegate:self                                                   cancelButtonTitle:@"取消"                                              destructiveButtonTitle:@"确认取消？" otherButtonTitles:@"Test1",@"Test2",@"Test4", nil];         [sheet showInView:self.view];               }     else if(buttonIndex  == 2)     {         NSLog(@"有所谓了");      }     else if (buttonIndex == 3) {          NSLog(@"无所谓了");     } else {     NSLog(@"不发表意见");  }  } 

//AlertView已经消失处理的事件 -(void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {  }

//AlertView即将消失时，处理的事件 -(void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex {  }  

//AlertView 取消时 -(void)alertViewCancel:(UIAlertView *)alertView {  } //AlertView已经显示的时候 -(void)didPresentAlertView:(UIAlertView *)alertView {  }  

//AlertView即将显示 -(void)willPresentAlertView:(UIAlertView *)alertView {  }

 UIActionSheet *sheet = [[UIActionSheet alloc] initWithTitle:@"操作选项" delegate:self                                                   cancelButtonTitle:@"取消"                                              destructiveButtonTitle:@"确认取消？" otherButtonTitles:@"Test1",@"Test2",@"Test4", nil];         [sheet showInView:self.view];

#pragma actionSheet  delegate  -(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {     if (buttonIndex == 0) {         NSLog(@"已经取消了");     }     if (buttonIndex == 1) {         UIAlertView *alerttest2 = [[UIAlertView alloc] initWithTitle:@"提示"                                                             message:@"你在ActionSheet这个test1按钮" delegate:self                                                   cancelButtonTitle:@"Cancel"                                                   otherButtonTitles:@"无所谓",@"有所谓", nil];         [alerttest2 addButtonWithTitle:@"不发表意见"];//可以在Alrt上再添加一个Button                           [alerttest2 show];     }  }  -(void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex {  } -(void)actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex {  }  -(void)actionSheetCancel:(UIActionSheet *)actionSheet {       }  -(void)didPresentActionSheet:(UIActionSheet *)actionSheet {   }  -(void)willPresentActionSheet:(UIActionSheet *)actionSheet {  }