android sdk---ImageView的切换

需求：

点击置左和置右按钮，底层图像进行切换，上层图像保持不动

代码如下：

private ImageView myImageView1;
 private ImageView myImageView2;
 private Button myButtonLeft;
 private Button myButtonRight;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        myImageView1 = (ImageView)findViewById(R.id.myImageView1);
        myImageView2 = (ImageView)findViewById(R.id.myImageView2);
        myButtonLeft = (Button)findViewById(R.id.button1);
        myButtonRight = (Button)findViewById(R.id.button2);

        myImageView1.setImageDrawable(getResources().getDrawable(R.drawable.right));
        myImageView1.setImageDrawable(getResources().getDrawable(R.drawable.oa));
       
        myButtonLeft.setOnClickListener(new Button.OnClickListener()
        {
       
   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    myImageView1.setImageDrawable(getResources().getDrawable(R.drawable.left));
   }});
       
        myButtonRight.setOnClickListener(new Button.OnClickListener()
        {
       
   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    myImageView1.setImageDrawable(getResources().getDrawable(R.drawable.right));
   }});

XML：

/*底层图像*/
    <ImageView
        android:id="@+id/myImageView1"
        android:layout_width="320px"
        android:layout_height="280px"
        android:layout_x="0px"
        android:layout_y="36px" />

/*上层图像*/
   <ImageView
        android:id="@+id/myImageView2"
        android:layout_width="104px"
        android:layout_height="157px"
        android:layout_x="101px"
        android:layout_y="119px"
        />
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_marginBottom="66dp"
        android:text="Left" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/button1"
        android:layout_alignParentRight="true"
        android:layout_marginRight="40dp"
        android:text="Right" />

ImageView的放置顺序和图层的顺序有关

重点：

ImageView设置图片

myImageView1.setImageDrawable(getResources().getDrawable(R.drawable.right));

eclipse 项目文件浏览界面消失了:

解决方式：WINDOW--->SHOW VIEW-->Package Exploer

在res/drawable中添加图片的方式：

将图片粘贴到项目res/drawable的文件夹下，重启一下eclipse就可以了（暂时是我采用的，应该有不用重启的办法）