Android TextView去掉paddingTop和paddingBottom

最近项目中需要用libgdx渲染一个Android的TextView， 但是绘制出来的TextView总是默认带有paddingTop和paddingBottom， 如下图所示：



网上有很多解决方案，例如在xml中设置如下属性：

android:lineSpacingMultiplier="0.8"
android:includeFontPadding="false"

或者设置margin为负值等等。 但是以上方法在6.0之后都没什么卵用。只有一种方法可以做到，就是自定义TextView

package com.ef.smallstar.common.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.support.annotation.NonNull;
import android.util.AttributeSet;

/**
* Created by Danny on 17/8/28.
*
* this is a Android TextView without padding top & padding bottom
*/

public class TextViewWithoutPadding extends android.support.v7.widget.AppCompatTextView {

private final Paint mPaint = new Paint();

private final Rect mBounds = new Rect();

public TextViewWithoutPadding(Context context) {
super(context);
}

public TextViewWithoutPadding(Context context, AttributeSet attrs) {
super(context, attrs);
}

public TextViewWithoutPadding(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

@Override
protected void onDraw(@NonNull Canvas canvas) {
final String text = calculateTextParams();

final int left = mBounds.left;
final int bottom = mBounds.bottom;
mBounds.offset(-mBounds.left, -mBounds.top);
mPaint.setAntiAlias(true);
mPaint.setColor(getCurrentTextColor());
canvas.drawText(text, -left, mBounds.bottom - bottom, mPaint);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
calculateTextParams();
setMeasuredDimension(mBounds.width() + 1, -mBounds.top + 1);
}

private String calculateTextParams() {
final String text = getText().toString();
final int textLength = text.length();
mPaint.setTextSize(getTextSize());
mPaint.getTextBounds(text, 0, textLength, mBounds);
if (textLength == 0) {
mBounds.right = mBounds.left;
}
return text;
}
}