Android实现TextView两端对齐的方法

package com.wedroid.framework.module.ui;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.text.TextPaint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.ViewGroup.MarginLayoutParams;
import android.view.ViewTreeObserver.OnPreDrawListener;
import android.widget.TextView;

public class WeDroidAlignTextView extends TextView {

  private boolean first = true;

  public WeDroidAlignTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
      @Override
      public boolean onPreDraw() {
        initTextInfo();
        return true;
      }
    });
  }

  public WeDroidAlignTextView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
  }

  public WeDroidAlignTextView(Context context) {
    this(context, null, 0);
  }

  private float textSize;
  private float textLineHeight;
  private int top;
  private int y;
  private int lines;
  private int bottom;
  private int right;
  private int left;
  private int lineDrawWords;
  private char[] textCharArray;
  private float singleWordWidth;

  private float lineSpacingExtra;

  public void initTextInfo() {
    textSize = getTextSize();
    textLineHeight = getLineHeight();
    left = 0;
    right = getRight();
    y = getTop();
    // 要画的宽度
    int drawTotalWidth = right - left;
    String text = getText().toString();
    if (!TextUtils.isEmpty(text) && first) {
      textCharArray = text.toCharArray();
      TextPaint mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
      mTextPaint.density = getResources().getDisplayMetrics().density;
      mTextPaint.setTextSize(textSize);
      // 一个单词的的宽度
      singleWordWidth = mTextPaint.measureText("一") + lineSpacingExtra;
      // 一行可以放多少个字符
      lineDrawWords = (int) (drawTotalWidth / singleWordWidth);
      int length = textCharArray.length;
      lines = length / lineDrawWords;
      if ((length % lineDrawWords) > 0) {
        lines = lines + 1;
      }
      first = false;
      MarginLayoutParams layoutParams = (MarginLayoutParams) getLayoutParams();
      int totalHeight = (int) (lines*textLineHeight+textLineHeight*2 + getPaddingBottom()+getPaddingTop()+layoutParams.bottomMargin+layoutParams.topMargin);
      setHeight(totalHeight);
    }
  }

  @Override
  protected void onDraw(Canvas canvas) {
    bottom = getBottom();
    int drawTotalLine = lines;

    if(maxLine!=0&&drawTotalLine>maxLine){
      drawTotalLine = maxLine;
    }

    for (int i = 0; i  length) {
          endTextIndex = length;
          y += textLineHeight;
        } else {
          y += textLineHeight;
        }
        for (; startIndex = 0x4e00) && (c <= 0x9FA5)) { 
        flag = true; 
      } 
    } 
    return flag; 
  }


  public static String ToDBC(String input) {
    // 导致TextView异常换行的原因：安卓默认数字、字母不能为第一行以后每行的开头字符，因为数字、字母为半角字符
    // 所以我们只需要将半角字符转换为全角字符即可
    char c[] = input.toCharArray();
    for (int i = 0; i