package com.francis.underlinetextviewtest;

import android.content.Context;

import android.content.res.Resources;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.util.Log;

import android.util.TypedValue;

import android.widget.TextView;

/**

 * Created by Francis on 14-10-13.

 */

public class UnderlineTextView extends TextView {

    private final Paint mPaint = new Paint();

    private int mUnderlineHeight = 0;

    public UnderlineTextView(Context context) {

        this(context, null);

    }

    public UnderlineTextView(Context context, AttributeSet attrs) {

        this(context, attrs, 0);

    }

    public UnderlineTextView(Context context, AttributeSet attrs, int defStyle) {

        super(context, attrs, defStyle);

        init(context, attrs);

    }

    private void init(Context context, AttributeSet attrs) {

        Resources r = getResources();

        // mUnderlineHeight == 6

        mUnderlineHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 2, r.getDisplayMetrics());

    }

    @Override

    public void setPadding(int left, int top, int right, int bottom) {

        super.setPadding(left, top, right, bottom + mUnderlineHeight);

    }

    @Override

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        // Draw the underline the same color as the text

        mPaint.setColor(getTextColors().getDefaultColor());

        // 对角线上的两点。

canvas.drawRect(0, getHeight() - mUnderlineHeight, getWidth(), getHeight(), mPaint);

    }

}

加入布局文件：

<com.francis.underlinetextviewtest.UnderlineTextView

        android:text="@string/hello_world"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textStyle="bold"

        android:textColor="#FFDDDDDD"/>