在 ConstraintLayout 中使用 group 来监听多个视图上的点击事件 [英] Use group in ConstraintLayout to listen for click events on multiple views

问题描述

基本上我想将一个 OnClickListener 附加到 ConstraintLayout 内的多个视图.

Basically I'd like to attach a single OnClickListener to multiple views inside a ConstraintLayout.

在迁移到 ConstraintLayout 之前，我可以在一个布局中添加一个监听器的视图.现在它们与 ConstraintLayout 正下方的其他视图位于同一层.

Before migrating to the ConstraintLayout the views where inside one layout onto which I could add a listener. Now they are on the same layer with other views right under the ConstraintLayout.

我尝试将视图添加到 android.support.constraint.Group 并以编程方式向其添加 OnClickListener.

I tried adding the views to a android.support.constraint.Group and added a OnClickListener to it programmatically.

group.setOnClickListener {
    Log.d("OnClick", "groupClickListener triggered")
}

然而，从 ConstraintLayout 版本 1.1.0-beta2

However this does not seem to work as of the ConstraintLayout version 1.1.0-beta2

我做错了什么，有没有办法实现这种行为，或者我是否需要将侦听器附加到每个单个视图?

Have I done something wrong, is there a way to achieve this behaviour or do I need to attach the listener to each of the single views?

推荐答案

ConstraintLayout 中的 Group 只是 AFAIK 视图的松散关联.它不是 ViewGroup，因此您将无法像在视图位于 ViewGroup 中时那样使用单击侦听器.

The Group in ConstraintLayout is just a loose association of views AFAIK. It is not a ViewGroup, so you will not be able to use a single click listener like you did when the views were in a ViewGroup.

作为替代方法，您可以在代码中获取属于您的 Group 成员的 id 列表，并显式设置点击侦听器.(我还没有找到关于这个功能的官方文档，但我相信它只是滞后于代码发布.) 查看关于 getReferencedIds 的文档此处.

As an alternative, you can get a list of ids that are members of your Group in your code and explicitly set the click listener. (I have not found official documentation on this feature, but I believe that it is just lagging the code release.) See documentation on getReferencedIds here.

Java:

    Group group = findViewById(R.id.group);
    int refIds[] = group.getReferencedIds();
    for (int id : refIds) {
        findViewById(id).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // your code here.
            }
        });
    }

在 Kotlin 中，您可以为此构建一个扩展函数.

In Kotlin you can build an extension function for that.

科特林:

    fun Group.setAllOnClickListener(listener: View.OnClickListener?) {
        referencedIds.forEach { id ->
            rootView.findViewById<View>(id).setOnClickListener(listener)
        }
    }

然后调用组上的函数:

    group.setAllOnClickListener(View.OnClickListener {
        // code to perform on click event
    })

更新

引用的 id 在 2.0.0-beta2 中并不立即可用，尽管它们在 2.0.0-beta1 和更早版本中可用.发布"上面的代码以在布局后获取参考 ID.像这样的东西会起作用.

The referenced ids are not immediately available in 2.0.0-beta2 although they are in 2.0.0-beta1 and before. "Post" the code above to grab the reference ids after layout. Something like this will work.

class MainActivity : AppCompatActivity() {
    fun Group.setAllOnClickListener(listener: View.OnClickListener?) {
        referencedIds.forEach { id ->
            rootView.findViewById<View>(id).setOnClickListener(listener)
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Referenced ids are not available here but become available post-layout.
        layout.post {
            group.setAllOnClickListener(object : View.OnClickListener {
                override fun onClick(v: View) {
                    val text = (v as Button).text
                    Toast.makeText(this@MainActivity, text, Toast.LENGTH_SHORT).show()
                }
            })
        }
    }
}

这应该适用于 2.0.0-beta2 之前的版本，因此您只需执行此操作而无需进行任何版本检查.

This should work for releases prior to 2.0.0-beta2, so you can just do this and not have to do any version checks.

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