java - 在循环中对可变文本使用 spannable

Question

所以我的应用程序应该将用户的输入与应用程序提供的随机引用进行比较，我想用绿色为正确的单词着色，用红色着色错误的单词。
问题是我不知道如何使用 Spannable在一个循环中，尤其是文本总是在变化。
这是代码:

if(quoteWords.length == resultWords.length){
                    
     for(int i = 0; i < quoteWords.length; i++) {
                        
         if (quoteWords[i].equals(resultWords[i])) { 
             //color the word with green               
         } else {
             //color the word with red               
         }
     }
                    
}

这就是我尝试过的:

    if(quoteWords.length == resultWords.length){
         SpannableStringBuilder fullStyledSentence = new SpannableStringBuilder();
         ForegroundColorSpan correctColor = new ForegroundColorSpan(Color.GREEN);
         ForegroundColorSpan wrongColor = new ForegroundColorSpan(Color.RED);
         int start;
    
         for(int i = 0; i < quoteWords.length; i++) {
              start = fullStyledSentence.length(); //get length of current SpannableString
              fullStyledSentence.append(quoteWords[i]);
    
              if (quoteWords[i].equals(resultWords[i])) { //color each word using its length
                    fullStyledSentence.setSpan(correctColor, start, start + quoteWords[i].length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                    Log.i("AzureSpeechRecognition", "word number " + i + "is correct");
                    } else {
                       fullStyledSentence.setSpan(wrongColor, start, start + quoteWords[i].length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                       Log.i("AzureSpeechRecognition", "word number " + i + "is wrong");
                    }
    
                       mQuoteBodyTextView.setText(null); //to delete repeatedly appended text
                       mQuoteBodyTextView.append(fullStyledSentence + " ");
              }
                        
     }

但结果文本没有着色，它们被粘在一起，没有空格。

Answer 1

看来ForegroundColorSpan/BackgroundColorSpan不可重用，每次我们都应该实例化一个新的。无论如何，我认为使用 SpannableString 写它更有意义。像下面这样:

public class MainActivity extends AppCompatActivity {

    // replacing all whitespaces with single space
    private String quote = "I want to color the correct word with green".replaceAll("\\s+", " ");
    private String result = "I want to color the right word with blue".replaceAll("\\s+", " ");

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

        String[] quoteWords = quote.split("\\s");
        String[] resultWords = result.split("\\s");

        SpannableString spannableQuote = new SpannableString(quote);

        if (quoteWords.length == resultWords.length) {
            int index = 0;
            for (int i = 0; i < quoteWords.length; i++) {
                spannableQuote.setSpan(
                    new BackgroundColorSpan(quoteWords[i].equals(resultWords[i]) ? Color.GREEN : Color.RED),
                    index,
                    index + quoteWords[i].length(),
                    SpannableString.SPAN_INCLUSIVE_INCLUSIVE
                );
                index += quoteWords[i].length() + 1; // 1 for the space between words
            }
        }

        ((TextView) findViewById(R.id.textView1)).setText(result);
        ((TextView) findViewById(R.id.textView2)).setText(spannableQuote);
    }
}

结果: