[Android] 圖片展示(ImageView)

我們來做個簡單的ImageView應用,
我們預設放一張紅色的花到ImageView,
當按下按鈕,即切換到藍色的花


1.加入Images到res/drawable-hdpi

2.加入ImageView及一個按鈕
res/layout/activity_main.xml

<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"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="flower1" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/button1"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="17dp"
        android:src="@drawable/flower2" />

</RelativeLayout>

3. MainActivity.java

 

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {
 Button button;
 ImageView image;
 boolean flowerImgShowed = false;

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

  addListenButton();
 }

 public void addListenButton() {

  image = (ImageView) findViewById(R.id.imageView1);

  button = (Button) findViewById(R.id.button1);
  button.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View arg0) {

    // 按下按鈕,來切換圖片
    if (!flowerImgShowed) {
     image.setImageResource(R.drawable.flower1);
     button.setText("Flower2);
     flowerImgShowed = true;
    } else {
     image.setImageResource(R.drawable.flower2);
     button.setText("Flower1");
     flowerImgShowed = false;
    }
   }

  });

 }

}

結果: