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我在尝试根据第一个字符在每行上设置不同的颜色时遇到问题。这是我目前拥有的。文本视图中没有任何内容。

TextView output=(TextView) findViewById(R.id.textView1);
    File file = new File("/sdcard/file.txt");
    StringBuilder text = new StringBuilder();
    try {
        BufferedReader br = new BufferedReader(new FileReader(file));
        String line;
        while ((line = br.readLine()) != null) {
            if (line.substring(0,1).equals("r")) {
                appendColoredText(output, line, Color.RED);
            } else if (line.substring(0,1).equals("y")) {
                appendColoredText(output, line, Color.YELLOW);
            } else if (line.substring(0,1).equals("c")) {
                appendColoredText(output, line, Color.CYAN);
            } else {
                appendColoredText(output, line, Color.BLACK);
            }
            //text.append('\n');
        }
        output.setText(text);
    }
    catch (IOException e) {
        Toast.makeText(getApplicationContext(),"Error reading file!",Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }

public static void appendColoredText(TextView tv, String text, int color) {
    int start = tv.getText().length();
    tv.append(text);
    int end = tv.getText().length();

    Spannable spannableText = (Spannable) tv.getText();
    spannableText.setSpan(new ForegroundColorSpan(color), start, end, 0);
}
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1 回答 1

2 
public void displayOutput()
{
    TextView output=(TextView) findViewById(R.id.textView1);
    output.setMaxLines(20000);
    //File sdcard = Environment.getExternalStorageDirectory();
    File file = new File("/sdcard/file.txt");
    try {
        BufferedReader br = new BufferedReader(new FileReader(file));
        String line;
        while ((line = br.readLine()) != null) {
            if (line.substring(0,1).equals("R")) {
                appendColoredText(output, line, Color.RED);
            } else if (line.substring(0,1).equals("Y")) {
                appendColoredText(output, line, Color.YELLOW);
            } else if (line.substring(0,1).equals("C")) {
                appendColoredText(output, line, Color.CYAN);
            } else {
                appendColoredText(output, line, Color.WHITE);
            }   
        }
    }
    catch (IOException e) {
        Toast.makeText(getApplicationContext(),"Error reading file!",Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }
}

public static void appendColoredText(TextView tv, String text, int color) {
    int start = tv.getText().length();
    tv.append(text);
    int end = tv.getText().length();
    Spannable spannableText = (Spannable) tv.getText();
    spannableText.setSpan(new ForegroundColorSpan(color), start, end, 0);
    tv.append("\n");
}

这是最终为我工作的代码

我的目标是逐行读取文本文件，并根据该行的第一个字符在 textview 中为该行分配一种颜色。我对原始代码的问题是文本视图中没有任何颜色出现。

于 2014-01-16T00:01:09.797 回答