TextView加边框，自定义，上下左右四条线 颜色，想用哪个用哪个

1.这是一个自定义的TextView ，看吧，底下就是代码，应该都可以看懂，这里就不多说了

package com.example.admin.myutilsborder;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.TextView;


/**
* Created by admin on 2017/3/7.
*/

public class BorderTextView extends TextView {
private boolean top_border ;
private boolean bottom_border;
private boolean left_border ;
private boolean right_border ;

public BorderTextView(Context context) {
super(context);
}
public BorderTextView(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.BorderTextView);
top_border =ta.getBoolean(R.styleable.BorderTextView_top_border,false);
bottom_border= ta.getBoolean(R.styleable.BorderTextView_bottom_border,false);
left_border= ta.getBoolean(R.styleable.BorderTextView_left_border,false);
right_border= ta.getBoolean(R.styleable.BorderTextView_right_border,false);
}
private int sroke_width = 1;

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint = new Paint();
// 将边框设为黑色
//paint.setColor(android.graphics.Color.RED);
paint.setColor(Color.GREEN);
// paint.setColor(Color.BLUE);
//paint.setColor(android.graphics.Color.alpha(717171));

// 画TextView的4个边
//drawLine方法参数顺序 左 上左
if(left_border){
canvas.drawLine(0, 0, 0, this.getHeight() - sroke_width, paint);
}
if(top_border){
canvas.drawLine(0, 0, this.getWidth() - sroke_width, 0, paint);
}
if(right_border){
canvas.drawLine(this.getWidth() - sroke_width, 0, this.getWidth() - sroke_width, this.getHeight() - sroke_width, paint);
}
if(bottom_border) {
canvas.drawLine(0, this.getHeight() - sroke_width, this.getWidth() - sroke_width, this.getHeight() - sroke_width, paint);
}

//上
//canvas.drawLine(0, 0, this.getWidth() - sroke_width, 0, paint);
//左
//canvas.drawLine(0, 0, 0, this.getHeight() - sroke_width, paint);
//右
// canvas.drawLine(this.getWidth() - sroke_width, 0, this.getWidth() - sroke_width, this.getHeight() - sroke_width, paint);
//下
//canvas.drawLine(0, this.getHeight() - sroke_width, this.getWidth() - sroke_width, this.getHeight() - sroke_width, paint);
//super.onDraw(canvas);
}

}

2.报错了，是不是，别急

在valus目录下新建一个attrs文件夹，注意：我这里使用Studio开发

 

<resources>


    <declare-styleable name="BorderTextView">
        <attr name="left_border"  format = "string"  />
        <attr name="right_border" format = "string"  />
        <attr name="top_border" format = "string"  />
        <attr name="bottom_border"  format = "string" />
        <attr name="mTextColor" format="color" />
        <attr name="mTextSize" format="dimension" />
    </declare-styleable>


</resources>

 

3.剩下的就是使用了，在XMl文件中

 

<com.example.admin.myutilsborder.BorderTextView    
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:top_border="true"
    app:bottom_border="true"
    app:left_border="true"
    app:right_border="true"
    android:text="Hello World!" />

<!--上面这里就是自定义的边框，需要上下左右哪个方向的线条就把它设置成true，不需要，直接删掉就好-->
4.最后一步，在Xml文件中

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
注意，多加了下面这条语句
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

完了，就这样简单的搞定了，简单的自定义，我这里就不过多的解释了，在碰见几个TextView放在一起，如果都设置边框的话，会让一部分线条变粗，当然，背景图也完全可以解决，但是搞技术嘛，简单的写写