我应该使用 WPF 转换器还是触发器? [英] Should I use WPF converter or trigger?

问题描述

我想知道您如何决定何时使用 converters 以及何时使用 triggers.我更喜欢在 GUI 上使用触发器进行操作(例如显示/隐藏控件、更改其外观等).

I was wondering how do you decide when to use converters and when to use triggers. I prefer using a triggers for operations on GUI (like showing/hiding controls, changing their appearance etc.).

前段时间我为此使用了 BooleanToVisibilityConverter 但现在，我只是不需要它，我使用触发器来完成与 visibility 相关的所有事情我什至开始思考MS 团队创建 BooleanToVisibilityConverter 的目的是什么?". 通常，如果可能，我会尝试使用声明性方式编写代码 - 在本例中 - XAML.

Some time ago I used a BooleanToVisibilityConverter for this purpose but now, I just don't need it, I do all things connected to the visibility using a triggers and I even started to think "what was the purpose of creating a BooleanToVisibilityConverter by the MS team?". Generally, when it's possible I try to use a declarative way to write the code - in this example - XAML.

您对此有何看法?

推荐答案

我同意你的看法，我也尝试在 XAML 中使用声明性代码并且更喜欢 Triggers 而不是 Converters>.

I agree with you, I also try to use declarative code in XAML and prefer Triggers instead of Converters.

在大多数情况下，触发器可以执行与任何转换器相同的工作，但 转换器 可以具有 pchajer 提到的自定义/业务逻辑.

In most of the scenarios triggers can perform the same work as any converter but Converters can have custom/business logic as pchajer mentioned.

Triggers 的一个限制是 DataTriggers 中的 Setter 只能更改 UI 元素的属性；所以，你不能用触发器更新你的 ViewModels 属性，这就是 Converters 获胜的地方，记住 ConvertBack 方法.

One limitation of Triggers is that Setters in your DataTriggers can only change properties of your UI elements; so, you can't update your ViewModels property with triggers, thats where Converters win, remember the ConvertBack method.

因此，您可以使用 BooleanToVisibilityConverter 将您的 VM 属性与控件 Visibility 绑定，即使您的控件 visibility 被更改为其他一些意味着您的 VM 属性将得到更新；通常不需要，这就是 BooleanToVisibilityConverter 被触发器替换的原因.

So, you can bind your VM property with a controls Visibility using BooleanToVisibilityConverter and even if your controls visibility is changed by some other means your VM property will get updated; generally it's not required that's why BooleanToVisibilityConverter gets replaced by triggers.

简而言之 -

Triggers 只能执行 OneWay 操作，而 Converters 可以执行 TwoWay 操作

Triggers can only perform OneWay operations whereas Converters can perform TwoWay operations

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