Question

我有一些代码可以创建barbuttonitem Edit，如果单击它并开始编辑，请将按钮更改为Done。

当我第一次创建按钮时，我将其动作设置为编辑。但是，一旦用户编辑，我想将重命名的按钮的操作更改为保存。

我以为我已经保存了射击，但是当我在中间添加一个方法来启用和禁用按钮时，它可能会停止工作。

有人可以建议更改条形按钮项的操作的正确方法吗？

这是我的代码：

  //code to create button which sets action to gotoEdit method
         UIBarButtonItem *editButton = [[UIBarButtonItem alloc] initWithTitle:@"Edit" style:UIBarButtonItemStylePlain target:self action:@selector(gotoEdit)];
            self.navigationItem.rightBarButtonItem = editButton;
        }
    -(void) gotoEdit {
        self.navigationItem.rightBarButtonItem.title = @"Done";
        _editButton.target = self;
        _editButton.action = @selector(save);//changes action to save method
//some other code to make a textview editable, change its background color and so forth.
       }
-(void) save {
NSLog(@"save method firing");
}
//I added the following methods at about the same time the save method stopped firing but not sure if they are related.  (Probably not but including them anyway.)
    //detect change on screen
    - (void)textViewDidChange:(UITextView *)textView{
        self.didChange=YES;
        [self updateSaveButton];
    }
    -(void) updateSaveButton
    {  
        self.editButton.enabled = (_didChange == TRUE);
    }

Answer 1

最好使用bool，而不是添加和删除按钮的操作。

-(void) gotoEdit {
    if(!isEditing){
        // Prep for editing
        self.navigationItem.rightBarButtonItem.title = @"Done";
        isEditing = true;
    }else{
        // Prep for saving
        self.navigationItem.rightBarButtonItem.title = @"Edit";
        isEditing = false;
    }     
}

为了将来参考，您可以删除按钮的选择器，如下所示：

[_editButton removeTarget:self 
               action:@selector(gotoEdit) 
     forControlEvents:UIControlEventTouchUpInside];

IOS：如何在创建UIBarButtonItem之后重置它的动作？

1 个答案: