android - 在 Android 中使用按钮滑动调整元素大小

Question

我有两个图像布局，当我向上滑动时，底部的一个在增长，上面的一个在缩小。当我向下滑动底部时，一个正在缩小，上面一个正在增长。这是 Java 代码:

public class MainActivity extends AppCompatActivity{

    GestureDetectorCompat detector;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final int minH = 350;
        final LinearLayout root = (LinearLayout) findViewById(R.id.root);
        final ImageView iv = (ImageView) findViewById(R.id.imageView);
        final ImageView iv2 = (ImageView) findViewById(R.id.imageView2);

        detector = new GestureDetectorCompat(this, new GestureDetector.SimpleOnGestureListener() {

            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                if ( iv == null || iv2 == null ) {
                    return true;
                }
                distanceY*=-1;
                int height = iv.getHeight ( ) + iv2.getHeight ( );
                ViewGroup.LayoutParams layoutParams = iv.getLayoutParams ( );
                if ( ( int ) distanceY + layoutParams.height < minH )
                    layoutParams.height = minH;
                else if ( ( int ) distanceY + layoutParams.height > height - minH )
                    layoutParams.height = height - minH;
                else
                    layoutParams.height = ( int ) distanceY + layoutParams.height;

                ViewGroup.LayoutParams layoutParams2 = iv2.getLayoutParams ( );
                layoutParams2.height = height - layoutParams.height;

                iv.setLayoutParams ( layoutParams );
                iv2.setLayoutParams ( layoutParams2 );

                return true;
            }
        });
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return detector.onTouchEvent(event);
    }
}

这是 XML:

<LinearLayout 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"
    tools:context=".MainActivity"
    android:id="@+id/root"
    android:orientation="vertical">

        <ImageView
            android:layout_width="match_parent"
            android:layout_weight="1"
            android:layout_height="0dp"
            android:id="@+id/imageView"
            android:layout_alignParentTop="true"
            android:scaleType="fitXY"
            android:src="@drawable/as" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:layout_below="@id/imageView"
            android:scaleType="fitXY"
            android:id="@+id/imageView2"

            android:src="@drawable/as" />
</LinearLayout>

这段代码运行良好。现在我要做的是。在这两个 ImageView 之间放置一个按钮。当你向上拖动按钮时，上面一个缩小，下面一个放大。向下拖动按钮时，下方一个缩小，上方一个增大。我怎样才能做到这一点？如何将按钮移动集成到此配置中？谢谢。

Answer 1

您只需要创建新的 ImageView，使其可点击以便它可以接收触摸事件并为其设置 onTouchListener:

activity_main.xml

<LinearLayout android:id="@+id/root"
              xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_alignParentTop="true"
        android:layout_weight="1"
        android:scaleType="fitXY"
        android:src="@drawable/as"/>

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_weight="1"
        android:clickable="true"
        android:scaleType="fitXY"
        android:src="@drawable/as"/>

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_below="@id/imageView"
        android:layout_weight="1"
        android:scaleType="fitXY"
        android:src="@drawable/as"/>
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    GestureDetectorCompat detector;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final int minH = 350;
        final LinearLayout root = (LinearLayout) findViewById(R.id.root);
        final ImageView iv = (ImageView) findViewById(R.id.imageView);
        final ImageView iv2 = (ImageView) findViewById(R.id.imageView2);
        final ImageView iv3 = (ImageView) findViewById(R.id.imageView3);

        detector = new GestureDetectorCompat(this, new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                if ( iv == null || iv3 == null ) {
                    return true;
                }
                distanceY*=-1;
                int height = iv.getHeight ( ) + iv3.getHeight ( );
                ViewGroup.LayoutParams layoutParams = iv.getLayoutParams ( );
                if ( ( int ) distanceY + layoutParams.height < minH )
                    layoutParams.height = minH;
                else if ( ( int ) distanceY + layoutParams.height > height - minH )
                    layoutParams.height = height - minH;
                else
                    layoutParams.height = ( int ) distanceY + layoutParams.height;

                ViewGroup.LayoutParams layoutParams2 = iv3.getLayoutParams ( );
                layoutParams2.height = height - layoutParams.height;

                iv.setLayoutParams ( layoutParams );
                iv3.setLayoutParams ( layoutParams2 );

                return true;
            }
        });

        iv2.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(final View view, final MotionEvent motionEvent) {
                return detector.onTouchEvent(motionEvent);
            }
        });
    }
}