Android控件— — —ImageView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/image_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="确认"
        android:layout_gravity="center"/>

</LinearLayout>

package com.example.uiwidgettest2;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.*;

public class edittextActivity extends Activity implements View.OnClickListener{

    private ImageView iv;
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.edittext);
        btn = (Button)findViewById(R.id.button);
        iv = (ImageView)findViewById(R.id.image_view);
        btn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.button:
                iv.setImageResource(R.drawable.dst);
                break;
            default:
                break;
        }
    }
}