在 Android 中对齐文本

Question

我需要证明一些文本 (RTL)，它是S1来自服务器的字符串 ( )。但是 aTextView不能对齐文本，所以我必须使用 a WebView，现在我必须创建一个 HTML 文件，其中将显示S1. 然后我将该 html 文件的地址存储在数据库中，然后显示该 html 文件。我之前在 SO 上看到过这个问题，很多人建议使用 3rd 方库，我尝试了所有这些方法都无济于事（它们在 90% 的情况下都有效，但并不完全可靠）。

我觉得这种方法看起来很复杂，我想知道是否有更好的方法？

Answer 1

我使用以下代码回答非常需要这个主题的人，我创建了在每个显示中都支持的公式。

    public class TextJustify {

final static String SYSTEM_NEWLINE = "\n";
final static float COMPLEXITY = 5.12f; // Reducing this will increase
                                        // efficiency but will decrease
                                        // effectiveness
final static Paint p = new Paint();

/* @author Mathew Kurian */

public static void run(final TextView tv, float origWidth, int paddingLeft, int paddingRight, int marginLeft, int marginRight) {


    origWidth-= paddingRight+marginRight+paddingLeft+marginLeft;
    String s = tv.getText().toString();
    p.setTypeface(tv.getTypeface());
    String[] splits = s.split(SYSTEM_NEWLINE);
    float width = origWidth - 5;
    for (int x = 0; x < splits.length; x++)
        if (p.measureText(splits[x]) > width) {
            splits[x] = wrap(splits[x], width, p);
            String[] microSplits = splits[x].split(SYSTEM_NEWLINE);
            for (int y = 0; y < microSplits.length - 1; y++)
                microSplits[y] = justify(removeLast(microSplits[y], " "),
                        width, p);
            StringBuilder smb_internal = new StringBuilder();
            for (int z = 0; z < microSplits.length; z++)
                smb_internal.append(microSplits[z]
                        + ((z + 1 < microSplits.length) ? SYSTEM_NEWLINE
                                : ""));
            splits[x] = smb_internal.toString();
        }
    final StringBuilder smb = new StringBuilder();
    for (String cleaned : splits)
        smb.append(cleaned + SYSTEM_NEWLINE);
    tv.setGravity(Gravity.RIGHT);
    tv.setText(smb);
}

private static String wrap(String s, float width, Paint p) {
    String[] str = s.split("\\s"); // regex
    StringBuilder smb = new StringBuilder(); // save memory
    smb.append(SYSTEM_NEWLINE);
    for (int x = 0; x < str.length; x++) {
        float length = p.measureText(str[x]);
        String[] pieces = smb.toString().split(SYSTEM_NEWLINE);
        try {
            if (p.measureText(pieces[pieces.length - 1]) + length > width)
                smb.append(SYSTEM_NEWLINE);
        } catch (Exception e) {
        }
        smb.append(str[x] + " ");
    }
    return smb.toString().replaceFirst(SYSTEM_NEWLINE, "");
}

private static String removeLast(String s, String g) {
    if (s.contains(g)) {
        int index = s.lastIndexOf(g);
        int indexEnd = index + g.length();
        if (index == 0)
            return s.substring(1);
        else if (index == s.length() - 1)
            return s.substring(0, index);
        else
            return s.substring(0, index) + s.substring(indexEnd);
    }
    return s;
}

private static String justifyOperation(String s, float width, Paint p) {
    float holder = (float) (COMPLEXITY * Math.random());
    while (s.contains(Float.toString(holder)))
        holder = (float) (COMPLEXITY * Math.random());
    String holder_string = Float.toString(holder);
    float lessThan = width;
    int timeOut = 100;
    int current = 0;
    while (p.measureText(s) < lessThan && current < timeOut) {
        s = s.replaceFirst(" ([^" + holder_string + "])", " "
                + holder_string + "$1");
        lessThan = p.measureText(holder_string) + lessThan
                - p.measureText(" ");
        current++;
    }
    String cleaned = s.replaceAll(holder_string, " ");
    return cleaned;
}

private static String justify(String s, float width, Paint p) {
    while (p.measureText(s) < width) {
        s = justifyOperation(s, width, p);
    }
    return s;
}
  }

为了调用它，您必须使用以下代码，我测试了波斯语，并且在每个显示器和设备上都运行良好。

     public static final int FinallwidthDp  = 320 ;
     public static final int widthJustify  = 223 ;

     DisplayMetrics metrics = new DisplayMetrics();
     getWindowManager().getDefaultDisplay().getMetrics(metrics);
     int widthPixels = metrics.widthPixels;

     float scaleFactor = metrics.density;
     float widthDp = widthPixels / scaleFactor;

     TextView tv = (TextView) findViewById(R.id.textView1);
     ViewGroup.MarginLayoutParams lp1 = (ViewGroup.MarginLayoutParams) tv.getLayoutParams();

     tv.setText(text);
     TextJustify.run(tv,widthDp / FinallwidthDp * widthJustify , tv.getPaddingLeft(),tv.getPaddingRight() , lp1.leftMargin, lp1.rightMargin);

该算法在各种设备上进行了测试，在正常活动（不是对话框）和wrap-content宽度中工作正常TextView，并且适用于每个填充和边距。如果不适合您，您可以更改widthJustify直到对您好看，我希望这有用。对于新更新，请参阅此