背景样式的改变方法:广播的方式

有时候我们看可以看到有些App可以动态改变背景样式，这时候我们可以利用广播的方式进行实现。

1.自定义广播类(图片存在于assets文件夹下)

class Receiver extends BroadcastReceiver{

@Override

public void onReceive(Context context, Intent intent) {

String path=intent.getStringExtra("path");

setBitmap(path);

}

}

@SuppressLint("NewApi")

public void setBitmap(String path){

AssetManager am=getAssets();

InputStream in=null;

try {

in=am.open("bkgs/"+path);

Bitmap bitmap=BitmapFactory.decodeStream(in);

layoutParent.setBackground(new BitmapDrawable(getResources(), bitmap));

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}finally{

try {

if(null!=in){

in.close();

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

2.注册广播

在onCreat()方法中注册广播

private Receiver mReceiver;

private void regiesterBgReceiver() {

mReceiver=new Receiver();

IntentFilter intent=new IntentFilter("CHANGE_BG");

registerReceiver(mReceiver, intent);

}

3.点击按钮  发送广播  改变样式

private void initEvent() {

btnChange.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

sendBroadCast("00"+(++i%10)+".jpg");

}

});

}

详细代码如下:

package com.example.test_bg2;

import java.io.IOException;

import java.io.InputStream;

import android.os.Bundle;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.content.res.AssetManager;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.ColorFilter;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.LinearLayout;

import android.widget.RelativeLayout;

public class MainActivity extends Activity {

    private Button btnChange;

    private RelativeLayout layoutParent;

    int i=0;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

btnChange=(Button) findViewById(R.id.btn_changeBg);

    layoutParent=(RelativeLayout) findViewById(R.id.layout_parent);

    regiesterBgReceiver();

    initEvent();

}

    private void initEvent() {

btnChange.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

sendBroadCast("00"+(++i%10)+".jpg");

}

});

}

    private void sendBroadCast(String path){

     Intent intent=new Intent("CHANGE_BG");

     intent.putExtra("path", path);

     sendBroadcast(intent);

    }

private Receiver mReceiver;

private void regiesterBgReceiver() {

mReceiver=new Receiver();

IntentFilter intent=new IntentFilter("CHANGE_BG");

registerReceiver(mReceiver, intent);

}

class Receiver extends BroadcastReceiver{

@Override

public void onReceive(Context context, Intent intent) {

String path=intent.getStringExtra("path");

setBitmap(path);

}

}

@SuppressLint("NewApi")

public void setBitmap(String path){

AssetManager am=getAssets();

InputStream in=null;

try {

in=am.open("bkgs/"+path);

Bitmap bitmap=BitmapFactory.decodeStream(in);

layoutParent.setBackground(new BitmapDrawable(getResources(), bitmap));

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}finally{

try {

if(null!=in){

in.close();

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

@Override

protected void onDestroy() {

super.onDestroy();

unregisterReceiver(mReceiver);

}

}

为了简单  这只是在单个Activity中进行实现背景样式的改变，如果改变所有的Activity样式，我们可以

自己封装BaseActivity  抽取出抽象方法供子类实现，从而改变整个应用的背景样式。

原文链接：http://www.apkbus.com/blog-813041-63559.html