Android WelcomeActivity 启动画更换网络图片

1、运行效果 

第一张是本地的启动图，第二张是网络启动图

     

2、用到的第三方jar包   Android-Universal-Image-Loader-master

    不熟的请看  Android-Universal-Image-Loader 框架使用

3、主要方法

（1）MyApplication

package com.app.android01 ;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
import android.app.Application;
import android.content.Context;
import android.graphics.Bitmap.Config;

public class MyApplication extends Application {

    public static DisplayImageOptions options; 

    @Override
    public void onCreate() {
        super.onCreate();
        initImageLoader( getApplicationContext() );
    }

    private void initImageLoader(Context context) {
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
        .threadPriority(Thread.NORM_PRIORITY - 2)
        .denyCacheImageMultipleSizesInMemory()
        .diskCacheExtraOptions(720, 1280, null)
        .diskCacheFileNameGenerator(new Md5FileNameGenerator())
        .diskCacheSize(50 * 1024 * 1024) // 50 Mb
        .tasksProcessingOrder(QueueProcessingType.LIFO)
        .diskCacheFileCount( 500 )
        .build();
        ImageLoader.getInstance().init( config );

        initOptions() ;
    }

    private void initOptions(){
        options = new DisplayImageOptions.Builder()
        .cacheInMemory(true)  //启用内存缓存
        .cacheOnDisk(true)    //启用磁盘缓存
        .considerExifParams(true)
        .bitmapConfig(Config.RGB_565 )
        .build();
    }
}

(2)WelcomeActivity

package com.app.android01 ;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.listener.SimpleImageLoadingListener;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.ImageView;

public class WelcomeActivity extends Activity {
    
    private boolean tag = true ;
    //总时间
    private int totalTime = 0 ; 

    //网络启动画
    private String imageString = "http://c.hiphotos.baidu.com/image/pic/item/8435e5dde71190efec7149d6cc1b9d16fdfa6035.jpg" ;

    private ImageView  welcome_image  ; 

    /**
     * Handler:跳转到不同界面
     */
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 1 :
                totalTime = totalTime + 200 ;

                if( totalTime == 3000 ){  //如果总时间大于3秒，就跳转到MainActivity,并且结束计数线程
                    tag = false ;
                    startActivity( new Intent( WelcomeActivity.this , MainActivity.class ));
                    finish() ;
                }
                break ;
            }
            super.handleMessage(msg);
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView( R.layout.activity_welcome ) ;
        welcome_image =  (ImageView) findViewById( R.id.welcome_image ) ;

        //启动记时工具
        new Thread(new ThreadShow()).start() ;

        ImageLoader.getInstance().loadImage( imageString , MyApplication.options , new SimpleImageLoadingListener(){
            @SuppressLint("NewApi") @Override
            public void onLoadingComplete(String imageUri, View view,
                    Bitmap loadedImage) {
                if( totalTime <= 800 ){   //如果在800毫秒内把网络图片加载出来就显示，否则就只显示本地的
                    Drawable drawable = new BitmapDrawable( WelcomeActivity.this.getResources(), loadedImage );
                    welcome_image.setBackground( drawable ) ;
                }
            }
        });
    }

    /**
     * 线程类
     * @author admin
     * 计时器
     */
    class ThreadShow implements Runnable {
        @Override
        public void run() {
            while ( tag ) {
                try {
                    Thread.sleep( 200 ); //每间隔200毫秒发送一次
                    Message msg = new Message();
                    msg.what = 1 ;
                    mHandler.sendMessage(msg);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

(3)MainActivity

package com.app.android01 ;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {

    private TextView textView ; 

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

        textView = (TextView) findViewById( R.id.tv ) ;
    }
}

4、所需要的权限

   <uses-permission android:name="android.permission.INTERNET" />
   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

5、项目下载地址

http://download.csdn.net/detail/yanzi2015/8890461