Android中一種歡迎界面模式

    package com.home.welcompage;  

    import java.util.Random;  

    import android.app.Activity;  
    import android.content.Intent;  
    import android.os.Bundle;  
    import android.os.Handler;  
    import android.os.Message;  
    import android.view.View;  
    import android.view.View.OnClickListener;  
    import android.view.animation.Animation;  
    import android.view.animation.AnimationUtils;  
    import android.widget.ImageView;  
    import android.widget.LinearLayout;  

    public class WelcomeActivity extends Activity {  
        private ImageView welcomeImage;  
        private Thread t1, t2;  
        private Handler handler;  
        private int rand = new Random().nextInt(4);;  
        private Animation animation;  
        private int pageNumber = 1;  

        @Override  
        protected void onCreate(Bundle savedInstanceState) {  
            super.onCreate(savedInstanceState);  
            setContentView(R.layout.welcome);  
            welcomeImage = (ImageView) findViewById(R.id.welcome_iv);  
            animation = AnimationUtils.loadAnimation(this, R.anim.scal_anim);  
            LinearLayout layout = (LinearLayout) findViewById(R.id.welcome_layout);  
            layout.setOnClickListener(new OnClickListener() {  

                @Override  
                public void onClick(View v) {  
                    if (pageNumber == 2) {  
                        t1.interrupt();  
                        t2.interrupt();  
                        turnPage();// 跳轉界面  
                    }  
                }  
            });  
            handler = new Handler() {  
                @Override  
                public void handleMessage(Message msg) {  
                    super.handleMessage(msg);  
                    if (msg.what == 0) {  
                        switch (rand) {  
                        case 0:  
                            // 設置動畫背景  
                            startAnimation(R.drawable.back1);  
                            break;  
                        case 1:  
                            startAnimation(R.drawable.back2);  
                            break;  
                        case 2:  
                            startAnimation(R.drawable.back3);  
                            break;  
                        case 3:  
                            startAnimation(R.drawable.back4);  
                            break;  
                        default:  
                            break;  
                        }  
                    }  
                }  
            };  
            t1 = new Thread(new Runnable() {  

                @Override  
                public void run() {  
                    try {  
                        Thread.sleep(3000);  
                        handler.sendEmptyMessage(0);  
                    } catch (InterruptedException e) {  
                        e.printStackTrace();  
                    }  
                }  
            });  
            t1.start();  
            t2 = new Thread(new Runnable() {  

                @Override  
                public void run() {  
                    try {  
                        Thread.sleep(4000);  
                        turnPage();// 跳轉界面  
                    } catch (InterruptedException e) {  
                        e.printStackTrace();  
                    }  
                }  
            });  
        }  

        /** 
         * 跳轉到主界面 
         */  
        private void turnPage() {  
            Intent intent = new Intent(WelcomeActivity.this, MainActivity.class);  
            WelcomeActivity.this.startActivity(intent);  
            WelcomeActivity.this.finish();  
        }  

        /** 
         * 設置動畫背景 
         *  
         * @param imageSource 
         */  
        private void startAnimation(int imageSource) {  
            welcomeImage.setBackgroundDrawable(getResources().getDrawable(  
                    imageSource));  
            welcomeImage.setAnimation(animation);  
            welcomeImage.startAnimation(animation);  
            t2.start();  
            pageNumber = 2;  
        }  
    }