连续延迟的android处理程序

Question

我正在编写一个应用程序来读取一行文本，并在读取行时连续突出显示每个单词。这个想法是开始玩线（这是一本儿童图画书，一次一行），然后阅读文本，以毫秒为单位的每个单词的长度，然后在正确的时间突出显示textview中的单词。

我的方法是： 将句子的单词放入一个数组中（并且最终每个作品的长度，但是暂时假设每个都为1000ms）; 将单词写入textViewPartial; 单词的延迟长度; 向句子添加下一个单词并将其写入textViewPartial ....等。

但我不能计算出时间。阅读我在处理程序和异步中可以找到的所有内容，最好的我可以提出如下 - 我在for循环中放置了一个postdelayed处理程序。我的大脑说它每次循环都会延迟，但是你可以从logcat输出中看到它不会。 for循环开始前只有一个延迟。这是我的第一篇文章，我不明白你是如何从Eclipse获取彩色代码的，所以我希望它看起来不错。

public class LineOutHanler extends Activity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_line_out_hanler); 
    TextView t = new TextView(this); 
    t=(TextView) findViewById (R.id.textView10); 
    String textOut = "Oh how my spleen aches to see you again"; 
    final TextView textViewPartial = (TextView) findViewById(R.id.textView11); 
    final String[] wordsOut = textOut.split(" "); 
    final int wordsInSentence = wordsOut.length; 
    int[] wordLength = new int[wordsInSentence]; 
      for (int counter=0;counter<=wordsInSentence-1;counter++){ 
      wordLength[counter]=wordsOut[counter].length();} 
    String partialSentence =""; 
    for (int counter=0; counter<=wordsInSentence-1; counter++){ 
      String c= addWordsOut(wordsOut[counter], partialSentence); 
      textViewPartial.setText(c); 
      partialSentence = c; 
      Log.d("Word", partialSentence); 
    final String partialOut=c; 
    final Handler handler = new Handler(); 
    handler.postDelayed(new Runnable() { 
     @Override 
     public void run() { 
         textViewPartial.setText(partialOut); 
      Log.d("Handler", partialOut); 
     } 
    } , 2000);} 
    } 
public String addWordsOut (String part, String upToHere) { 
upToHere=upToHere+" " + part; 
return upToHere; 
} 
} 

和logcat的输出：

10-19 23:07:32.248: E/cutils-trace(39): Error opening trace file: No such file or directory (2) 
10-19 23:07:32.368: D/AudioSink(39): bufferCount (4) is too small and increased to 12 
10-19 23:07:32.379: D/Word(821): Oh 
10-19 23:07:32.379: D/Word(821): Oh how 
10-19 23:07:32.388: D/Word(821): Oh how my 
10-19 23:07:32.388: D/Word(821): Oh how my spleen 
10-19 23:07:32.388: D/Word(821): Oh how my spleen aches 
10-19 23:07:32.388: D/Word(821): Oh how my spleen aches to 
10-19 23:07:32.388: D/Word(821): Oh how my spleen aches to see 
10-19 23:07:32.398: D/Word(821): Oh how my spleen aches to see you 
10-19 23:07:32.398: D/Word(821): Oh how my spleen aches to see you again 
10-19 23:07:33.328: I/Choreographer(288): Skipped 30 frames! The application may be doing too much work on its main thread. 
10-19 23:07:33.368: I/ActivityManager(288): Displayed com.example.testtextout/.LineOutHanler: +1s820ms 
10-19 23:07:35.320: W/AudioFlinger(39): write blocked for 1091 msecs, 1 delayed writes, thread 0x40e0b008 
10-19 23:07:35.320: D/Handler(821): Oh 
10-19 23:07:35.329: D/Handler(821): Oh how 
10-19 23:07:35.329: D/Handler(821): Oh how my 
10-19 23:07:35.329: D/Handler(821): Oh how my spleen 
10-19 23:07:35.329: D/Handler(821): Oh how my spleen aches 
10-19 23:07:35.329: D/Handler(821): Oh how my spleen aches to 
10-19 23:07:35.339: D/Handler(821): Oh how my spleen aches to see 
10-19 23:07:35.339: D/Handler(821): Oh how my spleen aches to see you 
10-19 23:07:35.339: D/Handler(821): Oh how my spleen aches to see you again 
10-19 23:08:30.588: D/dalvikvm(396): GC_FOR_ALLOC freed 452K, 15% free 3047K/3556K, paused 40ms, total 65ms 
10-19 23:25:42.149: D/dalvikvm(288): GC_FOR_ALLOC freed 850K, 31% free 5593K/7996K, paused 99ms, total 117ms 

第一个问题 - 这是摆在首位的正确方法？ 第二个问题 - 我怎样才能使它工作？

非常感谢。

Answer 1

问题出在您的for循环中。当您发布可运行的应用程序时，您总是会从当前时间点开始后续运行2000毫秒。当您的代码运行时，它几乎同时发布这些操作。因此，您看到您的输出在两秒钟后发生，同时发生。相反，你可以做下面的工作，根据你正在处理的是哪个单词，将其发布到将来2000ms的倍数。

for (int counter=0; counter<=wordsInSentence-1; counter++){ 
     String c= addWordsOut(wordsOut[counter], partialSentence); 
     textViewPartial.setText(c); 
     partialSentence = c; 
     Log.d("Word", partialSentence); 
     final String partialOut=c; 
     final Handler handler = new Handler(); 
     handler.postDelayed(new Runnable() { 
       @Override 
       public void run() { 
         textViewPartial.setText(partialOut); 
         Log.d("Handler", partialOut); 
       } 
     } , 2000*(counter+1)); 
} 

至于你的实现，我建议发布每个新的runnable，因为前一个完成。否则，您可以创建并发布许多可运行的代码，不必要地占用您的内存使用量，并且对处理程序进行清理是一件痛苦的事情。对于最初的POC来说，这并不算太坏，以后可以轻松更改。