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锁定老帖子 主题:用代理模式处理海量高频数据更新
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作者 | 正文 |
发表时间:2010-11-28
最后修改:2010-11-28
下面是部分实例代码,最后一个是模拟的数据更新。 public interface CommonDefn { public static int HIGHLIGHT_BACKGROUND_COLOR_INDEX = 0xff0033ff; public class DoThingsReturn{ public Object cmd; public Object data; public int errCode; public DoThingsReturn(Object cmd, Object data, int errorCode) { super(); this.cmd = cmd; this.data = data; this.errCode = errorCode; } } } /** * used for updating the background of the view while the data changed * * */ public interface RefreshHandlerInterface { public void updateBackground(Object handlerId, int color); //the proxy updating method public Handler getHandler(); //the proxy handler } /** * * decrease alpha channel value from 255 to 0. * */ public class ColorRefreshTask extends TimerTask { private RefreshHandlerInterface refreshHandler; private final static int DELAY_ONCE =200; private final static int TOTAL_RUNTIME = 1500; private final static int POWER_16_16 = 16 * 16* 16 * 16 * 16 * 16; private final static int INCREASE_ONCE = 0xff / (TOTAL_RUNTIME / DELAY_ONCE); private int color; private Object id; private int startTime; private int alphaChannel; /** * * @param color ( current background color) * @param id id of the updated view */ public ColorRefreshTask(RefreshHandlerInterface refreshHandler, int color, Object id) { super(); Log.d("color", "ready to set color!"); this.color = color; this.id = id; this.startTime = 0; this.alphaChannel = 0; this.refreshHandler = refreshHandler; } public void run(){ int colorComm = color - 0xff000000; //RGB color value; int currColor = 0; if(startTime < TOTAL_RUNTIME) { startTime += DELAY_ONCE; alphaChannel += INCREASE_ONCE; currColor = POWER_16_16 * alphaChannel + colorComm; //Log.d("color", Integer.toHexString(currColor)); sendMsg(currColor); refreshHandler.getHandler().postDelayed(this,DELAY_ONCE); } else { sendMsg(currColor <= color ? color : 0 ); cancel(); } } public void startTimer(){ refreshHandler.getHandler().postDelayed(this,DELAY_ONCE); } private void sendMsg(final int currColor){ final Runnable myUpdateResults = new Runnable() { public void run() { refreshHandler.updateBackground( id, currColor); } }; new Thread() { public void run() { refreshHandler.getHandler().post(myUpdateResults); } }.start(); } public void stopTimer(){ this.cancel(); } } import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.view.View; import android.widget.TextView; public class TestActivity extends Activity implements RefreshHandlerInterface{ private Handler _messageHandler = new Handler(); @Override public Handler getHandler() { return _messageHandler; } @Override public void updateBackground(Object handlerId, int color) { if(!( handlerId instanceof CommonDefn.DoThingsReturn)) { return; //invalid parameter } else { TextView current = (TextView)(((CommonDefn.DoThingsReturn)handlerId).data); if(current.getVisibility() != View.VISIBLE) { return; //no need to update for the view } if(color<=0) { current.setBackgroundDrawable(null); current.setText(((CommonDefn.DoThingsReturn)handlerId).cmd.toString()); } else { current.setBackgroundColor( color); } current.postInvalidate(); } } /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final TextView tv = (TextView)findViewById(R.id.txtview); new Thread() { java.util.Random rand = new java.util.Random(); long lastUpdate = System.currentTimeMillis(); public void run() { while(!Thread.interrupted() || !TestActivity.this.isFinishing()) { //模拟高频更新数据 if( System.currentTimeMillis() - lastUpdate < 2000l) { //设置两次动画的最少间隔时间 continue; } else lastUpdate = System.currentTimeMillis(); CommonDefn.DoThingsReturn updateWrapper = new CommonDefn.DoThingsReturn(String.valueOf(rand.nextInt()) , tv,0); ColorRefreshTask refresh = new ColorRefreshTask(TestActivity.this,CommonDefn.HIGHLIGHT_BACKGROUND_COLOR_INDEX, updateWrapper); _messageHandler.postDelayed(refresh, 200); //ready to for the current updating } } }.start(); } } 这也也打包了,需要的可以看一下。 声明:ITeye文章版权属于作者,受法律保护。没有作者书面许可不得转载。
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发表时间:2010-12-03
谢谢了,下来看看注释再多点就完美了。
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发表时间:2010-12-12
好吧.我承认.我看不太懂..
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