学步园

可以在开发过程为了让用户有更多的选择，会让用户自己选择背景图片（注意：不是主题哦！）,我写了一个小例子share一下。

效果图：

原理很简单：就是SharedPreferences保存默认背景图片，所有需要设置layout都加载背景图片。

例子结构

源代码

ChangeBackgroundActivity.java

package com.harlan;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;

/**
 * 更换应用背景图片
 * @author Harlan
 * 2012-5-8
 */
public class ChangeBackgroundActivity extends Activity implements
		OnClickListener {
	Button btn1, btn2, btn3, btn4;
	LinearLayout llayout;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		btn1 = (Button) findViewById(R.id.button1);
		btn2 = (Button) findViewById(R.id.button2);
		btn3 = (Button) findViewById(R.id.button3);
		btn4 = (Button) findViewById(R.id.button4);
		llayout = (LinearLayout) findViewById(R.id.llayout);
		SetBackgroundImage.setBackGround(ChangeBackgroundActivity.this, llayout);
		btn1.setOnClickListener(this);
		btn2.setOnClickListener(this);
		btn3.setOnClickListener(this);
		btn4.setOnClickListener(this);

	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.button1:
			Intent intent = new Intent(ChangeBackgroundActivity.this,
					Activity2.class);
			startActivity(intent);
			break;
		case R.id.button2:
			SetBackgroundImage.saveBackground(ChangeBackgroundActivity.this,
					"bg1");
			SetBackgroundImage.setBackGround(ChangeBackgroundActivity.this, llayout);
			break;
		case R.id.button3:
			SetBackgroundImage.saveBackground(ChangeBackgroundActivity.this,
					"bg2");
			SetBackgroundImage.setBackGround(ChangeBackgroundActivity.this, llayout);
			break;
		case R.id.button4:
			SetBackgroundImage.saveBackground(ChangeBackgroundActivity.this,
					"bg3");
			SetBackgroundImage.setBackGround(ChangeBackgroundActivity.this, llayout);
			break;

		}

	}
}

SetBackgroundImage.java

package com.harlan;

import android.app.Activity;
import android.content.SharedPreferences;
import android.view.View;

/**
 * 设置默认背景和更换背景
 * @author Harlan
 * 2012-5-7
 */
public class SetBackgroundImage {
	
	public static void changeBackgroundImage(int i) {

	}
	
	/**
	 * 设置背景图片
	 * @param activity
	 * @param view 在这里传的是LinearLayout
	 */
	public static void setBackGround(Activity activity, View view) {
		String bg = getBG(activity);
		if (bg != null) {
			if ("bg1".equals(bg)) {
				view.setBackgroundResource(R.drawable.bg1);
			}
			if ("bg2".equals(bg)) {
				view.setBackgroundResource(R.drawable.bg2);
			}
			if ("bg3".equals(bg)) {
				view.setBackgroundResource(R.drawable.bg3);
			}
		}else{
			saveBackground(activity,"bg1");
			view.setBackgroundResource(R.drawable.bg3);
		}

	}
	
	/**
	 * 更改默认背景图片
	 * @param activity
	 * @param imageTag	
	 */
	public static void saveBackground(Activity activity, String imageTag) {
		SharedPreferences preferences = activity.getSharedPreferences("bg",
				Activity.MODE_PRIVATE);
		SharedPreferences.Editor editor = preferences.edit();
		editor.putString("background", imageTag);
		editor.commit();

	}
	
	/**
	 * 得到默认图片标识
	 * @param activity
	 * @return 
	 */
	private static String getBG(Activity activity) {
		SharedPreferences preferences = activity.getSharedPreferences("bg",Activity.MODE_PRIVATE);
		String bg = preferences.getString("background", null);
		return bg;

	}
}

Activity2.java 没什么内容

main.xml

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

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" 
        />


    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="跳转下一个Activity看效果" />


    <Button
        android:id="@+id/button2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="背景一" />


    <Button
        android:id="@+id/button3"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="背景二" />


    <Button
        android:id="@+id/button4"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="背景三" />

</LinearLayout>

o分源代码下载：http://download.csdn.net/detail/mark_dev/4284540

Over。

ps：偶只是按照我自己想的写的方法，如果有什么好的方法记得分享也学习一下。如果兴趣的可以加载我们的QQ群（213167832）