iphone开发 UIActionSheet(操作表) 和UIAlertView(警告)的用法

一．UIActionSheet(操作表) 和UIAlertView(警告)
 
UIActionSheet用于迫使用户在两个或更多的选项之间进行选择的模式视图。操作表从屏幕底部弹出，显示一系列按钮供用户选择，用户只有单击一个按钮后才能继续使用应用程序。
UIAlertView警告以蓝色圆角矩形形式出现在屏幕中部，警报可显示一个或多个按钮
为了让控制器类充当操作表的委托，控制器需要遵从UIActionSheetDelegate协议
 
二．UIActionSheet(操作表)的创建
 
initWithTitle:delegate:cancelButtonTitle:destructiveButtonTitle:otherButtonTitles:
 
注释：initWithTitle是对象函数
            initWithTitle：操作表标题
            delegate：接收对象
     cancelButtonTitle关闭按钮标题
            destructiveButtonTitle: 操作按钮标题
            otherButtonTitles:其他按钮
 
1.   创建一个简单的操作表：
    //open a dialog with an OK and cancel button
    UIActionSheet*actionSheet = [[UIActionSheet alloc] 
                  initWithTitle:@" UIActionSheet<title>"
                   delegate:self  
                  cancelButtonTitle:@"Cancel"
                  destructiveButtonTitle:@"OK"
                    otherButtonTitles:nil];
 
    actionSheet.actionSheetStyle = UIActionSheetStyleDefault;
 
    [actionSheetshowInView:self.view]; //show from our table view (pops up in the middle of the table)
 
    [actionSheetrelease];

2.    创建两个按钮的操作表

            // open a dialog with an OKand cancel button

    UIActionSheet*actionSheet = [[UIActionSheet alloc]

                   initWithTitle:@" UIActionSheet<title>"

                    delegate:self

                   cancelButtonTitle:@"Cancel"

                    destructiveButtonTitle:@"OK"

                   otherButtonTitles:nil];

    actionSheet.actionSheetStyle = UIActionSheetStyleDefault;

    [actionSheetshowInView:self.view]; //show from our table view (pops up in the middle of the table)

    [actionSheetrelease];

3.   创建自定义操作表：

    //open a dialog with two custom buttons

    UIActionSheet*actionSheet = [[UIActionSheet alloc]

        &nbs