将笔划添加到按钮后如何删除笔划答案

【问题标题】：how to remove stroke after adding it to a button将笔划添加到按钮后如何删除笔划
【发布时间】：2018-02-28 11:37:02
【问题描述】：

我试图在按下按钮时为其添加边框（笔触），然后在按下另一个按钮时删除笔触。问题是按钮保持按钮+笔画的大小，而不是回到原始大小（没有笔画）

我尝试的代码如下所示：

front.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent event) {

            ShapeDrawable shapeDrawable = new ShapeDrawable();
            shapeDrawable.getPaint().setColor(Color.RED);
            shapeDrawable.getPaint().setStrokeWidth(30f);
            shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
            front.setBackgroundDrawable(shapeDrawable);

            return false;
        }
    });

    back.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent event) {

            ShapeDrawable shapeDrawable = new ShapeDrawable();
            shapeDrawable.getPaint().setColor(Color.GRAY);
            shapeDrawable.getPaint().setStrokeWidth(0f);
            shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
            front.setBackgroundDrawable(shapeDrawable);

            return false;
        }
    });

【问题讨论】：

标签： android android-button

【解决方案1】：

我发现解决此问题的最佳方法是将背景颜色设置为所需的颜色，而不是使可绘制对象为空。对于上面的代码示例，我放置了以下代码，以便能够将按钮恢复为灰色：

front.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent event) {

        ShapeDrawable shapeDrawable = new ShapeDrawable();
        shapeDrawable.getPaint().setColor(Color.RED);
        shapeDrawable.getPaint().setStrokeWidth(30f);
        shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
        front.setBackgroundDrawable(shapeDrawable);
        back.setBackgroundColor(Color.GRAY);

        return false;
    }
});

back.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent event) {

        ShapeDrawable shapeDrawable = new ShapeDrawable();
        shapeDrawable.getPaint().setColor(Color.GRAY);
        shapeDrawable.getPaint().setStrokeWidth(0f);
        shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
        back.setBackgroundDrawable(shapeDrawable);
        front.setBackgroundColor(Color.GRAY);

        return false;
    }
});

【讨论】：

【解决方案2】：

尝试将另一个按钮的背景可绘制对象设置为空。另外，请注意您在第二种方法中遇到了错误 - 您使用的是 front.setBackgroundDrawable(shapeDrawable); 而不是 back.setBackgroundDrawable(shapeDrawable);。供您使用的工作代码：

front.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent event) {

        ShapeDrawable shapeDrawable = new ShapeDrawable();
        shapeDrawable.getPaint().setColor(Color.RED);
        shapeDrawable.getPaint().setStrokeWidth(30f);
        shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
        front.setBackgroundDrawable(shapeDrawable);
        back.setBackgroundDrawable(null);

        return false;
    }
});

back.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent event) {

        ShapeDrawable shapeDrawable = new ShapeDrawable();
        shapeDrawable.getPaint().setColor(Color.GRAY);
        shapeDrawable.getPaint().setStrokeWidth(0f);
        shapeDrawable.getPaint().setStyle(Paint.Style.STROKE);
        back.setBackgroundDrawable(shapeDrawable);
        front.setBackgroundDrawable(null);

        return false;
    }
});

【讨论】：

将背景可绘制对象设置为 null 完全摆脱了按钮，只留下按钮上的文本。有没有办法将drawable设置为null但保留按钮的填充颜色？