在Android中，ShapeDrawable的烦人行为

Question

我正在使用ShapeDrawable作为LinearLayout的背景。由于需要根据条件动态分配颜色，因此形状是通过编码生成的。 这是我的自定义形状：

public class CustomShapeDrawable extends ShapeDrawable {
    private final Paint fillpaint, strokepaint, linePaint = new Paint();
    private int strokeWidth = 3;
    private final boolean disableBottomBorder;

    public CustomShapeDrawable(Shape s, int fill, int stroke, int strokewidth, boolean disablebottomborder) {
        super(s);
        fillpaint = new Paint(this.getPaint());
        fillpaint.setColor(fill);
        strokepaint = new Paint(fillpaint);
        strokepaint.setStyle(Paint.Style.STROKE);
        strokepaint.setStrokeWidth(strokewidth);
        strokepaint.setColor(stroke);
        linePaint.setStyle(Paint.Style.STROKE);
        linePaint.setStrokeWidth(strokewidth + 1);
        linePaint.setColor(fill);
        strokeWidth = strokewidth;
        disableBottomBorder = disablebottomborder;

    }

    public CustomShapeDrawable(Shape s, int fill, int stroke, boolean disablebottomborder) {
        super(s);
        fillpaint = new Paint(this.getPaint());
        fillpaint.setColor(fill);
        strokepaint = new Paint(fillpaint);
        strokepaint.setStyle(Paint.Style.STROKE);
        strokepaint.setStrokeWidth(strokeWidth);
        strokepaint.setColor(stroke);
        linePaint.setStyle(Paint.Style.STROKE);
        linePaint.setStrokeWidth(strokeWidth + 1);
        linePaint.setColor(fill);
        disableBottomBorder = disablebottomborder;
    }

    @Override
    protected void onDraw(Shape shape, Canvas canvas, Paint paint) {
        shape.resize(canvas.getClipBounds().right, canvas.getClipBounds().bottom);
        shape.draw(canvas, fillpaint);

        Matrix matrix = new Matrix();
        matrix.setRectToRect(new RectF(0, 0, canvas.getClipBounds().right, canvas.getClipBounds().bottom), new RectF(strokeWidth / 2, strokeWidth / 2, canvas.getClipBounds().right - strokeWidth / 2,
                canvas.getClipBounds().bottom - strokeWidth / 2), Matrix.ScaleToFit.FILL);
        canvas.concat(matrix);

        shape.draw(canvas, strokepaint);

        if (disableBottomBorder) {
            canvas.drawLine(0 + strokeWidth/2, shape.getHeight(), shape.getWidth() - strokeWidth/2, shape.getHeight(), linePaint);
        }
    }

这个CustomShapeDrawable被用作我布局的StateListDrawable，如下所示：

        RoundRectShape shapeTopCorners = new RoundRectShape(new float[] { 10, 10, 10, 10, 0, 0, 0, 0 }, null, null);
        ShapeDrawable shapeTopCornersNormal =
                new CustomShapeDrawable(shapeTopCorners, Global.getFleet().getSkins().getBackgroundcolour(), context.getResources().getColor(R.color.item_line), true);
        ShapeDrawable shapeTopCornersPressed =
                new CustomShapeDrawable(shapeTopCorners, context.getResources().getColor(R.color.menu_grey), context.getResources().getColor(R.color.item_line), true);

        StateListDrawable stateTopCornersRounded = new StateListDrawable();
        stateTopCornersRounded.addState(new int[] { android.R.attr.state_focused }, shapeTopCornersPressed);
        stateTopCornersRounded.addState(new int[] { android.R.attr.state_pressed }, shapeTopCornersPressed);
        stateTopCornersRounded.addState(new int[] {}, shapeTopCornersNormal);

一切看起来都很好，布局形状和我想要的颜色相同。但当屏幕上出现另一个元素，如键盘或AlertDialog时，丑陋的事情发生了。当我的应用再次获得焦点时，布局就会出现随机的线条和残留物。这就是我的意思：

图片链接: https://istack.dev59.com/KGUwh.webp 我该怎么做才能防止或修复这些残留物呢？它们看起来很丑陋。我不知道为什么会出现这种情况。谢谢你提供的任何帮助。

- Alin

Answer 1

目前没有任何建议，现在唯一能解决问题的方法是： - 我在我的活动中创建了一个名为invalidate()的方法，在我想要刷新所有布局的情况下，我添加了layoutId.invalidate() - 每当显示警报对话框时，调用invalidate() - 对于所有EditTexts onFocusChanged或onTextChanged，调用invalidate()

这不是一个很符合人体工程学的解决方案，但目前似乎可以工作。

- Alin