UIActionSheet实例，显示简单菜单

UIActionSheet实例，显示简单菜单。
采用滑动方式呈现在屏幕上，等待用户响应

显示菜单的方法：
1、showInView
2、showFromToolBar:和showFromTabBar

视图控制类需要是现实协议接口UIActionSheetDelegate

@interface HelloController : UIViewController <UIActionSheetDelegate>
@end

主要实现代码：

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    printf("User Pressed Button %d\n", buttonIndex + 1);
    [actionSheet release];
}

- (void) presentSheet
{
    UIActionSheet *menu = [[UIActionSheet alloc]
                           initWithTitle: @"File Management"
                           delegate:self
                           cancelButtonTitle:@"Cancel"
                           destructiveButtonTitle:@"Delete File"
                           otherButtonTitles:@"Rename File", @"Email File", nil];
    [menu showInView:self.view];
}

类学习

UIActionSheet类

继承UIView

Use the UIActionSheet class to present the user with a set of alternatives for how to proceed with a given task. You can also use action sheets to prompt the user to confirm a potentially dangerous action. The action sheet contains an optional title and one or more buttons, each of which corresponds to an action to take.

使用UIActionSheet类呈现给用户一系列交替选项用于决定如何处理所给的任务。你也可以使用动作表来提示用户确认具有潜在危险的动作。动作表包含可选标题和1个或多个按钮，每个按钮对应响应所给的动作。

Creating Action Sheets

    – initWithTitle:delegate:cancelButtonTitle:destructiveButtonTitle:otherButtonTitles:

Setting Properties

      delegate  property
      title  property
      visible  property
      actionSheetStyle  property

Configuring Buttons

    – addButtonWithTitle:
      numberOfButtons  property
    – buttonTitleAtIndex:
      cancelButtonIndex  property
      destructiveButtonIndex  property
      firstOtherButtonIndex  property

Presenting the Action Sheet

    – showFromTabBar:
    – showFromToolbar:
    – showInView:
    – showFromBarButtonItem:animated:
    – showFromRect:inView:animated:

Dismissing the Action Sheet

    – dismissWithClickedButtonIndex:animated:

备注：比对学习下UIAlertView，你会发现这两个类基本类似

这里还有一组常量值
UIActionSheetStyle

Specifies the style of an action sheet.

typedef enum {
   UIActionSheetStyleAutomatic        = -1,
   UIActionSheetStyleDefault          = UIBarStyleDefault,
   UIActionSheetStyleBlackTranslucent = UIBarStyleBlackTranslucent,
   UIActionSheetStyleBlackOpaque      = UIBarStyleBlackOpaque,
} UIActionSheetStyle;

Constants

UIActionSheetStyleAutomatic

    Takes the appearance of the bottom bar if specified; otherwise, same as UIActionSheetStyleDefault.

UIActionSheetStyleDefault

    The default style.

UIActionSheetStyleBlackTranslucent

    A black translucent style.

UIActionSheetStyleBlackOpaque

    A black opaque style.


协议接口学习

UIActionSheetDelegate协议接口

The UIActionSheetDelegate protocol defines the methods a delegate of a UIActionSheet object should implement. The delegate implements the button actions and any other custom behavior. Some of the methods defined in this protocol are optional.

Responding to Actions

    – actionSheet:clickedButtonAtIndex:

Customizing Behavior

    – willPresentActionSheet:
    – didPresentActionSheet:
    – actionSheet:willDismissWithButtonIndex:
    – actionSheet:didDismissWithButtonIndex:

Canceling

    – actionSheetCancel:

看来，这里和UIAlertViewDelegate接口也类似，学起来也方便多了，good