我找到了一种更好的方法来在TextView周围添加边框。

使用九块图像作为背景。它非常简单，SDK附带了一个制作9补丁图像的工具，而且它绝对不需要编码。

链接是http://developer.android.com/guide/topics/graphics/2d-graphics.html#nine-补丁。

试试看：

<shape>
    <solid android:color="@color/txt_white"/>
    <stroke android:width="1dip" android:color="@color/border_black"/>
</shape>

简单的方法是为TextView添加视图。底部边框线示例：

<LinearLayout android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:text="@string/title"
        android:id="@+id/title_label"
        android:gravity="center_vertical"/>
    <View
        android:layout_width="fill_parent"
        android:layout_height="0.2dp"
        android:id="@+id/separator"
        android:visibility="visible"
        android:background="@android:color/darker_gray"/>

</LinearLayout>

对于其他方向的边框，请调整分隔符视图的位置。

我通过扩展文本视图并手动绘制边框解决了这个问题。我甚至添加了这样的选项，您可以选择边框是虚线还是虚线。

public class BorderedTextView extends TextView {
        private Paint paint = new Paint();
        public static final int BORDER_TOP = 0x00000001;
        public static final int BORDER_RIGHT = 0x00000002;
        public static final int BORDER_BOTTOM = 0x00000004;
        public static final int BORDER_LEFT = 0x00000008;

        private Border[] borders;

        public BorderedTextView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
            init();
        }

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

        public BorderedTextView(Context context) {
            super(context);
            init();
        }
        private void init(){
            paint.setStyle(Paint.Style.STROKE);
            paint.setColor(Color.BLACK);
            paint.setStrokeWidth(4);        
        }
        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            if(borders == null) return;

            for(Border border : borders){
                paint.setColor(border.getColor());
                paint.setStrokeWidth(border.getWidth());

                if(border.getStyle() == BORDER_TOP){
                    canvas.drawLine(0, 0, getWidth(), 0, paint);                
                } else
                if(border.getStyle() == BORDER_RIGHT){
                    canvas.drawLine(getWidth(), 0, getWidth(), getHeight(), paint);
                } else
                if(border.getStyle() == BORDER_BOTTOM){
                    canvas.drawLine(0, getHeight(), getWidth(), getHeight(), paint);
                } else
                if(border.getStyle() == BORDER_LEFT){
                    canvas.drawLine(0, 0, 0, getHeight(), paint);
                }
            }
        }

        public Border[] getBorders() {
            return borders;
        }

        public void setBorders(Border[] borders) {
            this.borders = borders;
        }
}

边框类：

public class Border {
    private int orientation;
    private int width;
    private int color = Color.BLACK;
    private int style;
    public int getWidth() {
        return width;
    }
    public void setWidth(int width) {
        this.width = width;
    }
    public int getColor() {
        return color;
    }
    public void setColor(int color) {
        this.color = color;
    }
    public int getStyle() {
        return style;
    }
    public void setStyle(int style) {
        this.style = style;
    }
    public int getOrientation() {
        return orientation;
    }
    public void setOrientation(int orientation) {
        this.orientation = orientation;
    }
    public Border(int Style) {
        this.style = Style;
    }
}

希望这对某人有所帮助：）

可以将可绘制的形状（矩形）设置为视图的背景。

<TextView android:text="Some text" android:background="@drawable/back"/>

和矩形drawable back.xml（放入res/drawable文件夹）：

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
   <solid android:color="@android:color/white" />
   <stroke android:width="1dip" android:color="#4fa5d5"/>
</shape>

您可以使用@android:color/transparent作为纯色，使其具有透明的背景。您还可以使用填充将文本与边框分开。有关详细信息，请参阅：http://developer.android.com/guide/topics/resources/drawable-resource.html

使用材质组件库，可以使用MaterialShapeDrawable。

    <TextView
        android:id="@+id/textview"
        .../>

然后可以通过编程方式应用MaterialShapeDrawable：

    TextView textView = findViewById(R.id.textview);
    MaterialShapeDrawable shapeDrawable = new MaterialShapeDrawable();
    shapeDrawable.setFillColor(ContextCompat.getColorStateList(this,android.R.color.transparent));
    shapeDrawable.setStroke(1.0f, ContextCompat.getColor(this,R.color....));
    ViewCompat.setBackground(textView,shapeDrawable);