如何将一组字符串发送到UIActionSheet varargs init方法？ [英] How can I sent an array of strings into an UIActionSheet varargs init method?

问题描述

我有一个行动表，其中的选项会根据具体情况而有所不同。有足够的不同按钮标题，我想首先构建这些按钮标题的数组，但我无法弄清楚如何将其转换为varargs格式。

I have an action sheet with options that vary depending on the circumstances. There are enough different button titles that I would like to construct an array of those button titles first, but I can't figure out how to convert that into the varargs format.

我想做这样的事情：

NSMutableArray *buttonTitles = [NSMutableArray array];
if (condition1) {
    [buttonTitles addObject: @"Do action 1"];
}
if (condition2) {
    [buttonTitles addObject: @"Do action 2"];
}
if (condition3) {
    [buttonTitles addObject: @"Do action 3"];
}
if (condition4) {
    [buttonTitles addObject: @"Do action 4"];
}
UIActionSheet *actionSheet = [[[UIActionSheet alloc] initWithTitle: nil delegate: self cancelButtonTitle: @"Cancel" destructiveButtonTitle: nil otherButtonTitles: buttonTitles] autorelease];

现在很明显，如果我必须这样做，我可以这样做：

Now obviously if I had to I could do something like this instead:

UIActionSheet *actionSheet = nil;
if (condition1 && condition2 && condition3 && condition4) {
    actionSheet = [[[UIActionSheet alloc] initWithTitle: nil delegate: self cancelButtonTitle: @"Cancel" destructiveButtonTitle: nil otherButtonTitles: @"Do action1", @"Do action2", @"Do action3", @"Do action 4", nil] autorelease];    
} else if (condition1 && condition2 && condition3 && !condition4) {
    actionSheet = [[[UIActionSheet alloc] initWithTitle: nil delegate: self cancelButtonTitle: @"Cancel" destructiveButtonTitle: nil otherButtonTitles: @"Do action1", @"Do action2", @"Do action3", nil] autorelease];    
} 
// else ...
// about 14 other cases!

但这太可怕了。有人知道一些很好的语法糖来帮助我吗？

But that would be horrible. Anyone know some nice syntactic sugar to help me out?

编辑：
有人建议我使用 addButtonWithTitle ，面对它看起来很棒，不幸的是，这会在取消按钮之后放置其他按钮，这是不可取的。

It has been suggested that I use addButtonWithTitle, which on the face of it looks great, unfortunately it this puts the additional buttons after the cancel button, which isn't desirable.

我认为这是Apple代码的错误，因为他们在 addButtonWithTitle 上的文档声明：

I believe this is bug with Apple's code since their documentation on addButtonWithTitle states:

// adds a button with the title. returns the index (0 based) of where it was added. buttons are displayed in the order added except for the
// destructive and cancel button which will be positioned based on HI requirements. buttons cannot be customized.

HI要求（Apple自己的人机界面指南）赞成取消按钮低于所有其他选项，所以我' d说苹果搞砸了。当然，这并没有真正帮助我，所以我回到尝试在NSArray和varargs之间进行转换，我仍然不知道该怎么做。

HI requirements (Apple's own Human Interface guidelines) favor the cancel button below all other options, so I'd say Apple screwed up. Of course, that doesn't really help me, so I'm back to trying to convert between an NSArray and a varargs, which I still don't know how to do.

推荐答案

你可以试试这个

NSMutableArray *buttonTitles = [NSMutableArray array];
if (condition1) {
    [buttonTitles addObject: @"Do action 1"];
}
if (condition2) {
    [buttonTitles addObject: @"Do action 2"];
}
if (condition3) {
    [buttonTitles addObject: @"Do action 3"];
}
if (condition4) {
    [buttonTitles addObject: @"Do action 4"];
}
[buttonTitles addObject: @"Cancel"];
UIActionSheet *actionSheet = [[[UIActionSheet alloc] initWithTitle: nil delegate: self cancelButtonTitle: nil destructiveButtonTitle: nil otherButtonTitles: nil] autorelease];

for (NSString *title in buttonTitles) {
    [actionSheet addButtonWithTitle: title];
}

[actionSheet setCancelButtonIndex: [buttonTitles count] - 1];

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