如何在带有数据绑定的checkChanged事件上绑定RadioGroup上的方法 [英] How to bind method on RadioGroup on checkChanged event with data-binding

问题描述

我正在互联网上搜索如何在 RadioGroup 上执行新的酷炫的android数据绑定，但没有找到任何有关它的博客文章。

I was searching over the internet for how to perform the new cool android data-binding over the RadioGroup and I didn't find a single blog post about it.

这是一个简单的场景，基于选中的单选按钮，我想使用android数据绑定附加回调事件。我在xml部分上找不到任何允许我定义回调的方法。

Its a simple scenario, based on the radio button selected, I want to attach a callback event using android data binding. I don't find any method on the xml part which allows me to define a callback.

就像这里是我的RadioGroup：

Like here is my RadioGroup:

      <RadioGroup
            android:id="@+id/split_type_radio"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:checkedButton="@+id/split_type_equal"
            android:gravity="center"
            <!-- which tag ? -->
            android:orientation="horizontal">

           ...

       </RadioGroup>

我如何附加将在 RadioGroup上调用的处理程序方法的 checkChnged 事件将使用数据绑定触发吗？

How do I attach a handler method which will be called on RadioGroup's checkChnged event will fire using data-binding?

我尝试使用 onClick （不知道是否相同），并在Activity中定义方法，并使用它在布局文件中定位它：

I have tried using onClick (don't know if it is the same) in layout file and defining method in the Activity and located it using this in the layout file:

   <variable
        name="handler"
        type="com.example.MainActivity"/>

  ...
   <RadioGroup
        android:onClick="handler.onCustomCheckChanged"
        .. >

然后定义方法 onCustomCheckChanged ，如下所示：

And defined method onCustomCheckChanged like this:

public void onCustomCheckChanged(RadioGroup radio, int id) {
     // ...
}

但是，它给了我编译错误：

But, it gives me the compilation error:

错误：（58，36）具有方法onClick的侦听器类android.view.View.OnClickListener与任何方法处理程序的签名都不匹配。onCustomCheckChanged

Error:(58, 36) Listener class android.view.View.OnClickListener with method onClick did not match signature of any method handler.onCustomCheckChanged

我见过很多博客都提到 RadioGroup 是有可能的，但是没有一个人真的说过。如何使用数据绑定处理此问题？

I have seen many blogs mentioning it is possible with RadioGroup but non of them really say how. How can I handle this with data-binding ?

推荐答案

在研究了一堆方法之后，我发现了关于SO的这个问题，它帮助我了解了如何绑定侦听器的单个方法。

After digging to the bunch of methods, I found this question on SO which helped me understand how to bind single methods of listeners.

这是RadioGroup的处理方法：

Here is what to do with RadioGroup:

在 RadioGroup 侦听器中，您有一个方法 onCheckedChanged（RadioGroup g，int id）。因此，您可以将该方法的实例作为变量传递到布局文件中，然后调用具有相同签名的方法，从而将该方法直接绑定到处理程序或活动。

In RadioGroup listener you have a method onCheckedChanged(RadioGroup g, int id). So you can directly bound that method to your handler or your activity by passing an instance of it as a variable in layout file and calling a method with the same signature.

So像这样调用布局文件：

So call on layout file like this:

  <RadioGroup
        android:id="@+id/split_type_radio"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:checkedButton="@+id/split_type_equal"
        android:gravity="center"
        android:onCheckedChanged="@{handler.onSplitTypeChanged}"
        android:orientation="horizontal">

       ...

   </RadioGroup>

在我的活动或处理程序中，我只需要简单地提供具有相同名称和签名的方法，就像这样：

And in my activity or handler, I need to simply provide the method with same name and signature like this:

public void onSplitTypeChanged(RadioGroup radioGroup,int id) {
  // ...
}

只需确保方法是公共的。

Just make sure method is public.

注意：：此方法适用于任何（大多数情况下，我还没有尝试全部）侦听器方法。像 EditText 一样，您可以提供 android：onTextChanged 等。

NOTE: This works for any (most of, I have not tried all) listener methods. Like for EditText you can provide android:onTextChanged and so on.

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