我在一个按钮上有 LinearLayout。 有没有办法处理按钮点击事件？

Question

i have one android activity xml and his xml inside make main RelativeLayout.that RelativeLayout inside add one Button and one linearlayout and i have clicking on button but not click,because of that button overly linear layout

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <Button
        android:id="@+id/btnTest"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:id="@+id/parentLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

    </LinearLayout>

</RelativeLayout>

getActivity().findViewById(R.id.btnTest).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e(TAG, "onClick: ");
            }
        });

click to print log.

Answer 1

Try this:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/parentLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

    </LinearLayout>

    <Button
        android:id="@+id/btnTest"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

Android xml views are created like a stack where views lower in the xml file are rendered on top of those earlier in the file.

It sounds like your linear layout is intercepting touch events preventing them from being propagated to the button underneath it.

A way to check this is to set a background on the linear layout, you'll see that when it has a coloured background the button is not visible.

Update:

Since there is a requirement to allow touch events for both the button and the layout I'll extend my solution.

OnClickListeners are the standard method for receiving tap events on android views. However lower down there are OnTouchListeners which handle raw touches on a view rather than click events.

When the android screen is touched in any way the event is recorded and android will send an on touch event to the first view that touch event would encounter. OnTouchListeners return a boolean indicating whetehr they consumed the event. If they did not consume the event then it is propagated to the next view down in the hierarchy which the touch event would encounter.

This is why your button's on click was originally never being registered as the layout was consuming the touch event and preventing it from being propagated to the button.

This is the standard android behaviour, only one view will handle any single touch event.

A decision to do otherwise is a sign that you should consider the design for your application and decide if this behaviour is definitely necessary.

However, in case your circumstances are one of the rare ocassions I'll provide and example on touch listener.

Please note, this on touch listener assumes that you are using the xml I posted above as well as he on click listener attached to the button in the original question.

getActivity()
    .findViewById(R.id.parentLayout)
    .setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                Log.e(TAG, "onTouch: ");
                return false;
            }
        });

This however will trigger both when user touches the layout and again when they release as those are two seperate motion events.

To trigger only on one type of motion event you will need to examine the passed event.

getActivity()
        .findViewById(R.id.parentLayout)
        .setOnTouchListener(new OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    if (event.getAction() == MotionEvent.ACTION_UP) {
                       Log.e(TAG, "onTouch: ");
                    }
                    return false;
                }
            });

In this code the log will only occur when the user lifts their finger from the view as ACTION_UP is the event action for a user lifting their finger.

Answer 2

The relative layout is same as Linear Layout which preserves the order of elements added inside it. you added Button first and Linear Layout second thats why button has gone below the linear layout hence you are not able to click on it. tale the linear layout above the button view and you will see the button and do the remaing part by java coding