android 自定义 按钮, 实现不同角的圆角 ,添加边框

布局中写法

<ZTButton
            android:layout_width="300dp"
            android:layout_height="100dp"
            android:layout_gravity="center"
            android:layout_margin="20dp"
            android:text="圆角按钮"
            android:textColor="#ffffff"
            android:textSize="30sp"
            zt_btn:bgColor="@color/colorPrimaryDark"
            zt_btn:borderColor="#ff0000"
            zt_btn:borderWidth="5dp"
            zt_btn:bottom_left_radius="0"
            zt_btn:bottom_right_radius="100"
            zt_btn:radius="20"
            zt_btn:shape="rectangle"
            zt_btn:top_left_radius="100"
            zt_btn:top_right_radius="0" />

attrs.xml 文件中添加如下代码

 <declare-styleable name="ZTButton">
        <attr name="bgColor" format="color" /><!--背景颜色-->
        <attr name="borderWidth" format="dimension" /><!--边框宽度-->
        <attr name="borderColor" format="color" /><!--边框颜色-->
        <attr name="radius" format="float" /><!--圆角-->
        <attr name="top_left_radius" format="float" /><!--圆角左上-->
        <attr name="top_right_radius" format="float" /><!--圆角右上-->
        <attr name="bottom_left_radius" format="float" /><!--圆角左下-->
        <attr name="bottom_right_radius" format="float" /><!--圆角右下-->
        <attr name="shape">
            <enum name="rectangle" value="0" /><!--矩形（圆角矩形）-->
            <enum name="oval" value="1" /><!--椭圆，圆-->
            <enum name="line" value="2" /><!--线-->
            <enum name="ring" value="3" /><!--圆环-->
        </attr>
    </declare-styleable>

控件代码

/**
 * 作者:zt
 * 时间:on 18/12/26
 * 说明: 自定义 按钮, 实现不同角的圆角 ,添加边框
 */
public class ZTButton extends android.support.v7.widget.AppCompatButton {
    //形状 图
    private GradientDrawable shapeDrawable;

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

    public ZTButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ZTButton);
        if (a != null) {
            //背景颜色
            int bgColor = a.getColor(R.styleable.ZTButton_bgColor, 0);
            setBgColor(bgColor);
            //获取形状
            int shape = a.getInteger(R.styleable.ZTButton_shape, 0);
            setShape(shape);
            //获取圆角
            float radius = a.getFloat(R.styleable.ZTButton_radius, 0);
            setRadius(radius);
            //获取左上圆角
            float topLeftRadius = a.getFloat(R.styleable.ZTButton_top_left_radius, 0);
            //获取右上圆角
            float topRightRadius = a.getFloat(R.styleable.ZTButton_top_right_radius, 0);
            //获取左下圆角
            float bottomLeftRadius = a.getFloat(R.styleable.ZTButton_bottom_left_radius, 0);
            //获取右下圆角
            float bottomRightRadius = a.getFloat(R.styleable.ZTButton_bottom_right_radius, 0);
            if (topLeftRadius != 0 || bottomLeftRadius != 0 || topRightRadius != 0 || bottomRightRadius != 0) {
                setRadius(topLeftRadius, topRightRadius, bottomLeftRadius, bottomRightRadius);
            }
            //边框宽度
            int borderWidth = (int) a.getDimension(R.styleable.ZTButton_borderWidth, 0);
            //边框颜色
            int borderColor = a.getColor(R.styleable.ZTButton_borderColor, bgColor);
            setBorder(borderWidth, borderColor);
        }
    }

    /**
     * 设置边框
     *
     * @param borderColor 边框颜色
     * @param borderWidth 边框宽度
     */
    private void setBorder(int borderWidth, @ColorInt int borderColor) {
        getGradientDrawable();
        shapeDrawable.setStroke(borderWidth, borderColor);
        setDrawable(shapeDrawable);
    }

    /**
     * 设置背景颜色
     *
     * @param bgColor
     */
    private void setBgColor(@ColorInt int bgColor) {
        getGradientDrawable();
        shapeDrawable.setColor(bgColor);
        setDrawable(shapeDrawable);
    }


    /**
     * 设置圆角
     *
     * @param radius 角度
     */
    private void setRadius(float radius) {
        getGradientDrawable();
        shapeDrawable.setCornerRadius(radius);
        setDrawable(shapeDrawable);
    }


    /**
     * 设置圆角
     *
     * @param topLeftRadius     左上
     * @param topRightRadius    右上
     * @param bottomLeftRadius  左下
     * @param bottomRightRadius 右下
     */
    private void setRadius(float topLeftRadius, float topRightRadius, float bottomLeftRadius, float bottomRightRadius) {
        getGradientDrawable();
        shapeDrawable.setCornerRadii(new float[]{
                topLeftRadius, topLeftRadius,
                topRightRadius, topRightRadius,
                bottomRightRadius, bottomRightRadius,
                bottomLeftRadius, bottomLeftRadius
        });
        setDrawable(shapeDrawable);
    }


    /**
     * 设置图形类型
     *
     * @param shape 形状
     */
    private void setShape(int shape) {
        getGradientDrawable();
        shapeDrawable.setShape(shape);
        setDrawable(shapeDrawable);
    }


    /**
     * 设置背景
     *
     * @param drawable 背景
     */
    private void setDrawable(Drawable drawable) {
        setBackgroundDrawable(drawable);
    }

    /**
     * 获取需要设置到背景的图片
     */
    private void getGradientDrawable() {
        if (shapeDrawable == null) {
            shapeDrawable = new GradientDrawable();
        }
    }

}