android textView 排版显示参差不齐的解决方法

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.widget.TextView;

public class JustifyTextView extends TextView {
private int mLineY;
private int mViewWidth;
public static final String TWO_CHINESE_BLANK = "  ";

public JustifyTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right,int bottom){
super.onLayout(changed, left, top, right, bottom);
}
@Override	protected void onDraw(Canvas canvas) {
TextPaint paint = getPaint();
paint.setColor(getCurrentTextColor());
paint.drawableState = getDrawableState();
mViewWidth = getMeasuredWidth();
String text = getText().toString();
mLineY = 0;
mLineY += getTextSize();
Layout layout = getLayout();

if (layout == null) {
return;
}
Paint.FontMetrics fm = paint.getFontMetrics();
int textHeight = (int) (Math.ceil(fm.descent - fm.ascent));
textHeight = (int) (textHeight * layout.getSpacingMultiplier() + layout.getSpacingAdd());
for (int i = 0; i < layout.getLineCount(); i++) {
int lineStart = layout.getLineStart(i);
int lineEnd = layout.getLineEnd(i);
float width = StaticLayout.getDesiredWidth(text, lineStart,
lineEnd, getPaint());
String line = text.substring(lineStart, lineEnd);
if(i < layout.getLineCount() - 1) {
if (needScale(line)) {
drawScaledText(canvas, lineStart, line, width);
} else {
canvas.drawText(line, 0, mLineY, paint);
}
} else {
canvas.drawText(line, 0, mLineY, paint);
}			mLineY += textHeight;
}
}
private void drawScaledText(Canvas canvas, int lineStart, String line,float lineWidth) {
float x = 0;
if (isFirstLineOfParagraph(lineStart, line)) {
String blanks = "  ";
canvas.drawText(blanks, x, mLineY, getPaint());
float bw = StaticLayout.getDesiredWidth(blanks, getPaint());
x += bw;
line = line.substring(3);
}
int gapCount = line.length() - 1;
int i = 0;
if (line.length() > 2 && line.charAt(0) == 12288
&& line.charAt(1) == 12288) {
String substring = line.substring(0, 2);
float cw = StaticLayout.getDesiredWidth(substring, getPaint());
canvas.drawText(substring, x, mLineY, getPaint());
x += cw;
i += 2;
}
float d = (mViewWidth - lineWidth) / gapCount;
for (; i < line.length(); i++) {
String c = String.valueOf(line.charAt(i));
float cw = StaticLayout.getDesiredWidth(c, getPaint());
canvas.drawText(c, x, mLineY, getPaint());
x += cw + d;
}
}

private boolean isFirstLineOfParagraph(int lineStart, String line) {
return line.length() > 3 && line.charAt(0) == ' '
&& line.charAt(1) == ' ';
}

private boolean needScale(String line) {
if (line == null || line.length() == 0) {
return false;
} else {
return line.charAt(line.length() - 1) != '\n';
}
}

}