In the app I've been working on, I would like to have a multiple-state (in my case, three) toggle button, instead of the two that ToggleButton provides. I've tried to start my own that extends Button, following the CompoundButton source, but quite honestly reading over its source got a bit overwhelming.

有没有办法做到只使用一个选择XML或什么的，或者是另一种方法，我还没有想到一个三态切换按钮？我宁愿在如何做到这一点的损失。

Is there a way to do a three-state toggle button using just a selector xml or something, or perhaps another method I haven't thought of? I'm rather at a loss of how to do this.

推荐答案

您可以自定义一个选择作为背景，有三个条目使用。现在的问题是按钮的属性，你可以使用选择。您可以有两个布尔属性，比如说A和B，在A，B，和默认来定义选择。 （A和和B将满足A，所以更恰当，他们可以被认为是A，A和！和B，以及A和！＆安培;！b）你可以重载现有属性（选择，有重点等），或者，更优雅，定义使用配方描述在这个线程自己的自定义属性。

You can certainly define a selector to use as a background that has three entries. The question is what button attributes you can use for the selector. You can have two boolean attributes, say A and B, and define the selector in terms of A, B, and default. (A && B will satisfy A, so more properly they could be thought of as A, !A && B, and !A && !B.) You can overload existing attributes (selected, focused, etc.) or, more elegantly, define your own custom attributes using the recipe described in this thread.