不可能更改UIBarButtonItem标题？ [英] Changing UIBarButtonItem title impossible?

问题描述

愚蠢的是，如果满足for循环中的某个条件，我正在尝试更改UIBarButtonItem上的标题。但是我遇到了麻烦。

Silly thing, I am trying to change the title on a UIBarButtonItem if a certain condition in a for-loop is met. However I'm having trouble.

我试过了

self.barButtonItem.title=@"NewTitle"

和

[self.barButtonItem setTitle:@"New Title"];

我甚至在视图上做了一个setNeedsDisplay而没有任何运气。顺便说一句，是的，我从self.navigationBar.items获取旧的按钮数组，删除旧按钮，并设置新按钮。

I even did a setNeedsDisplay on the view afterwards without any luck. By the way, yes I am getting the old array of buttons from self.navigationBar.items, removing the old button, and setting the new one.

如果我改变了屏幕方向（翻转ipad），按钮标题确实改变。但除此之外，它保持不变。

If I change the screen orientation (flip ipad), the button title does change. But otherwise, it stays the same.

我错过了什么？

推荐答案

问题

如果您浏览文档，Apple会说：

If u explore the documentation, apple says :

你应该在将项目添加到栏之前设置此属性。

"You should set this property before adding the item to a bar."

因此，

cancel_btn.title = "something"  // It does not work !

因为您已将项目设置为栏。

Because u already set the item to the bar.

解决方案

//
let theTitle = "something"

//
self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: theTitle, style: 
UIBarButtonItemStyle.plain, target: self, action: 
#selector(cancelAction))

现在你在将项目添加到栏之前设置标题。

Now u set the title before adding the item to the bar.

这篇关于不可能更改UIBarButtonItem标题？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！