通过onClickListener更改ImageView的位置

Question

我想创建一个程序，当我按下向上按钮时，球图像移向顶部 1px
当我按向下按钮时，图像移动到底部。

现在告诉我如何获得此输出。

Answer 1

我做了一个requiremens的演示项目，这就是代码的样子：

布局：

<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">


<ImageView
    android:id="@+id/ballImage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:background="@drawable/ic_launcher"/>


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_alignParentBottom="true"
    android:gravity="center">
<Button
    android:id="@+id/upBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Up" />

<Button
    android:id="@+id/downBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Down" />


<Button
    android:id="@+id/leftBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Left" />

<Button
    android:id="@+id/rightBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Right" />
</LinearLayout>

</RelativeLayout>

活动代码：

 import android.app.Activity;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.view.Window;
 import android.view.WindowManager;
 import android.widget.Button;
 import android.widget.ImageView;
 import android.widget.Toast;


public class MyActivity extends Activity implements View.OnClickListener{

private Button upBtn;
private Button downBtn;
private Button leftBtn;
private Button rightBtn;
private ImageView ballImage;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //Remove title bar
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    //Remove notification bar
    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_my);

    init();
}


public void init(){

    ballImage = (ImageView)findViewById(R.id.ballImage);

    upBtn = (Button) findViewById(R.id.upBtn);
    upBtn.setOnClickListener(this);
    downBtn = (Button) findViewById(R.id.downBtn);
    downBtn.setOnClickListener(this);
    leftBtn = (Button) findViewById(R.id.leftBtn);
    leftBtn.setOnClickListener(this);
    rightBtn = (Button) findViewById(R.id.rightBtn);
    rightBtn.setOnClickListener(this);

}


@Override
public void onClick(View v) {
    switch (v.getId()){

        case R.id.upBtn:{
            Toast.makeText(this,"UP",Toast.LENGTH_SHORT).show();
            int[] locations = new int[2];
            ballImage.getLocationOnScreen(locations);
            ballImage.setX(locations[0]);
            ballImage.setY(locations[1]-1);
            Log.i("COORD X","X: "+locations[0]);
            Log.i("COORD Y","Y: "+locations[1]);
            break;
        }

        case R.id.downBtn:{
            Toast.makeText(this,"DOWN",Toast.LENGTH_SHORT).show();
            int[] locations = new int[2];
            ballImage.getLocationOnScreen(locations);
            ballImage.setX(locations[0]);
            ballImage.setY(locations[1]+1);
            Log.i("COORD X","X: "+locations[0]);
            Log.i("COORD Y","Y: "+locations[1]);
            break;
        }

        case R.id.leftBtn:{
            Toast.makeText(this,"LEFT",Toast.LENGTH_SHORT).show();
            int[] locations = new int[2];
            ballImage.getLocationOnScreen(locations);
            ballImage.setX(locations[0]-1);
            Log.i("COORD X","X: "+locations[0]);
            Log.i("COORD Y","Y: "+locations[1]);
            break;
        }

        case R.id.rightBtn:{
            Toast.makeText(this,"RIGHT",Toast.LENGTH_SHORT).show();
            int[] locations = new int[2];
            ballImage.getLocationOnScreen(locations);
            ballImage.setX(locations[0]+1);
            Log.i("COORD X","X: "+locations[0]);
            Log.i("COORD Y","Y: "+locations[1]);
            break;
        }


    }
}
}

最终结果：

我用图片作为默认图标。