java - 为什么我无法检测到 ScrollView 内的滑动？

Question

我的 xml 中有这个:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/jokeIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:contentDescription="@string/app_name"
        />

    <ScrollView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_below="@+id/jokeIcon" >

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/allJokesTxt"
                style="?android:textAppearanceMedium"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:gravity="center"
                android:lineSpacingMultiplier="1.2"
                android:padding="16dp" />

        </LinearLayout>
    </ScrollView>

</RelativeLayout>

我的 Activity 中的这段代码:

public boolean onTouchEvent(MotionEvent event) {

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                x1 = event.getX();
                break;
            case MotionEvent.ACTION_UP:
                x2 = event.getX();
                float deltaX = x2 - x1;

                if (Math.abs(deltaX) > MIN_DISTANCE) {
                    changeText();

                } else {
                    // consider as something else - a screen tap for example
                }
                break;
        }
        return super.onTouchEvent(event);
    }


 private void changeText(){
    // Left to Right swipe action
    if (x2 > x1) {
        if (jokesCounter > 0) {
            --jokesCounter;
            currentJoke.setVisibility(View.VISIBLE);
            currentJoke.setText(jokesCollector.get(jokesCounter));
        } else {
            Context context = getApplicationContext();
            CharSequence text = "xxx";
            int duration = Toast.LENGTH_SHORT;

            Toast toast = Toast.makeText(context, text, duration);
            toast.show();
        }

    }

    // Right to left swipe action
    else {
        if (jokesLengthCounter >= jokesCounter) {
            ++jokesCounter;

            currentJoke.setVisibility(View.VISIBLE);
            currentJoke.setText(jokesCollector.get(jokesCounter));
        } else {
            Context context = getApplicationContext();
            CharSequence text = "xxx";
            int duration = Toast.LENGTH_SHORT;

            Toast toast = Toast.makeText(context, text, duration);
            toast.show();
        }

    }

现在这应该是在用户从左向右或相反方向滑动时更改屏幕上的文本。问题是滑动只有在 ìmageView 上完成时才会被检测到，我的意思是 ScrollView(在实际的 textView 上)内部的滑动没有被检测到全部。

为什么会这样？我知道我在这里遗漏了一个极小的部分，但我现在无法发现它。你能推我一下吗？

Answer 1

你必须为 ScrollView 覆盖 onInterceptTouchEvent 它允许你将触摸事件传递给它的 subview

您可以引用:ScrollView with children view, how to intercept scroll conditionally

引用:http://developer.android.com/reference/android/view/ViewGroup.html#onInterceptTouchEvent%28android.view.MotionEvent%29