UIActionSheet没有显示半透明

Question

我想从rootViewController中显示一个非常简单的UIActionsheet：

- (void)viewWillAppear:(BOOL)animated {
  asButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(showActionSheet:)];
}

-(IBAction) showActionSheet:(id)sender {

    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:nil delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil 
                                             otherButtonTitles:@"Add current location", @"Center map", nil];

    [actionSheet setActionSheetStyle:UIActionSheetStyleBlackTranslucent];

    [actionSheet showFromBarButtonItem:asButton animated:YES];

    [actionSheet release];
}

然而，出乎意料的是，它显示为不透明...... 万一重要：工具栏直接在appDelegate的窗口上创建为子视图（并且是半透明的）：

CGRect toolbarFrame = CGRectMake(toolbarxOffset, toolbaryOffset, toolbarWidth,
                                 toolbarHeight);

self.myToolbar = [[UIToolbar alloc] initWithFrame:toolbarFrame];
[self.myToolbar setBarStyle:UIBarStyleBlack];
[self.myToolbar setTranslucent:YES];
[window addSubview:self.myToolbar];

有人对此有解释吗？

Answer 1

在寻找不相关的东西时，我发现了这个：

iPhone development: How to create colored or translucent background for UIActionSheet?

也许这可以帮助...