IOS UIMenuController UIMenuItem，如何确定用通用选择器方法选择的项目 [英] IOS UIMenuController UIMenuItem, how to determine item selected with generic selector method

问题描述

使用以下设置

....
MyUIMenuItem *someAction  = [[MyUIMenuItem alloc]initWithTitle : @"Something"  action : @selector(menuItemSelected:)];
MyUIMenuItem *someAction2 = [[MyUIMenuItem alloc]initWithTitle : @"Something2" action : @selector(menuItemSelected:)];
....

- (IBAction) menuItemSelected : (id) sender
{
    UIMenuController *mmi = (UIMenuController*) sender;
}

如何确定选择了哪个菜单项。

How to figure out which menu item was selected.

并且不要说你需要有两种方法......提前致谢。

And don't say that you need to have two methods... Thanks in advance.

推荐答案

好的，我已经解决了这个问题。解决方案并不漂亮，更好的选择是Apple修复问题，但这至少有效。

Okay, I've solved this one. The solution isn't pretty, and the better option is "Apple fixes the problem", but this at least works.

首先，在 UIMenuItem前面加上前缀带有 magic _ 的动作选择器。并且不要制作相应的方法。 （如果你能做到这一点，那么你无论如何都不需要这个解决方案。）

First of all, prefix your UIMenuItem action selectors with "magic_". And don't make corresponding methods. (If you can do that, then you don't need this solution anyway).

我正在构建我的 UIMenuItems ：

NSArray *buttons = [NSArray arrayWithObjects:@"some", @"random", @"stuff", nil];
NSMutableArray *menuItems = [NSMutableArray array];
for (NSString *buttonText in buttons) {
    NSString *sel = [NSString stringWithFormat:@"magic_%@", buttonText];
    [menuItems addObject:[[UIMenuItem alloc] 
                         initWithTitle:buttonText
                         action:NSSelectorFromString(sel)]];
}
[UIMenuController sharedMenuController].menuItems = menuItems;

现在你的班级抓住按钮点击消息需要一些补充。 （在我的例子中，该类是 UITextField 的子类。你的可能是其他东西。）

Now your class that catches the button tap messages needs a few additions. (In my case the class is a subclass of UITextField. Yours might be something else.)

首先，我们的方法所有人都希望拥有但不存在：

First up, the method that we've all been wanting to have but that didn't exist:

- (void)tappedMenuItem:(NSString *)buttonText {
    NSLog(@"They tapped '%@'", buttonText);
}

然后是可行的方法：

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    NSString *sel = NSStringFromSelector(action);
    NSRange match = [sel rangeOfString:@"magic_"];
    if (match.location == 0) {
        return YES;
    }
    return NO;
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)sel {
    if ([super methodSignatureForSelector:sel]) {
        return [super methodSignatureForSelector:sel];
    }
    return [super methodSignatureForSelector:@selector(tappedMenuItem:)];
}

- (void)forwardInvocation:(NSInvocation *)invocation {
    NSString *sel = NSStringFromSelector([invocation selector]);
    NSRange match = [sel rangeOfString:@"magic_"];
    if (match.location == 0) {
        [self tappedMenuItem:[sel substringFromIndex:6]];
    } else {
        [super forwardInvocation:invocation];
    }
}

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