动态绘制背景不同弧度的TextView

先上实现代码：

/**
 * @desc 带有角度的 textview
 * @createtime: 2021/3/25
 */
public class CornerTextView extends AppCompatTextView {
    private String tag = "CornerTextView";
    private int mBackgroundColor = -1;
    private Paint bgPaint;

    private int leftTop;
    private int leftBottom;
    private  int rightTop;
    private int rightBottom;

    private Path path = new Path();
    private  RectF rect = new RectF();

    public CornerTextView(@NonNull Context context) {
        this(context, null);
    }

    public CornerTextView(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, -1);
    }

    public CornerTextView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        //初始化 画笔
        bgPaint = new Paint();
        bgPaint.setAntiAlias(true);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //需要提前绘制背景色，要不然是覆盖在文字上面了
        drawCornerBg(canvas);
        super.onDraw(canvas);

    }

    //绘制带有角度的背景色
    private void drawCornerBg(Canvas canvas) {
        if (mBackgroundColor == -1) {
            return;
        }
        if (leftTop == 0 && leftBottom == 0 && rightBottom == 0 && rightTop == 0) {
            //只需要设置背景色即可
            setBackgroundColor(mBackgroundColor);
            return;
        }
        float[] outerR = new float[]{leftTop, leftTop, rightTop, rightTop, rightBottom, rightBottom, leftBottom, leftBottom};//左上，右上，右下，左下
        rect.left = 0;
        rect.right = getWidth();
        rect.top = 0;
        rect.bottom = getHeight();
        path.addRoundRect(rect, outerR, Path.Direction.CW);
        canvas.drawPath(path, bgPaint);
    }

    public void setCorner(int corner) {
        this.leftTop = corner;
        this.rightTop = corner;
        this.leftBottom = corner;
        this.rightBottom = corner;
    }

    public void setCorner(int leftTop, int rightTop, int leftBottom, int rightBottom) {
        this.leftTop = leftTop;
        this.rightTop = rightTop;
        this.leftBottom = leftBottom;
        this.rightBottom = rightBottom;
    }

    public void setBgBackGround(@ColorInt int color) {
        bgPaint.setColor(color);
        mBackgroundColor = color;
    }

    //动态设置好背景色和弧度后，调用刷新，重新绘制
    public void afterOkInvalidate() {
        invalidate();
    }
}

主要实现代码就一块：

根据角度，确认path路径，添加到绘制页面绘制即可，省却了通过shape 固定定义图形的尴尬

    //绘制带有角度的背景色
    private void drawCornerBg(Canvas canvas) {
        if (mBackgroundColor == -1) {
            return;
        }
        if (leftTop == 0 && leftBottom == 0 && rightBottom == 0 && rightTop == 0) {
            //只需要设置背景色即可
            setBackgroundColor(mBackgroundColor);
            return;
        }
        float[] outerR = new float[]{leftTop, leftTop, rightTop, rightTop, rightBottom, rightBottom, leftBottom, leftBottom};//左上，右上，右下，左下
        rect.left = 0;
        rect.right = getWidth();
        rect.top = 0;
        rect.bottom = getHeight();
        path.addRoundRect(rect, outerR, Path.Direction.CW);
        canvas.drawPath(path, bgPaint);
    }

若是想通过xml布局定义好背景色和弧度，可以自定义控件属性来现实。

代码使用示例：

        LinearLayout ll_container = findViewById(R.id.ll_container);

        CornerTextView cornerTextView = new CornerTextView(this);

        cornerTextView.setPadding(15,8,18,8);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        params.bottomMargin=50;
        ll_container.addView(cornerTextView,params);


        cornerTextView.setText("感觉到很干净回到家");
        cornerTextView.setTextSize(16);
        cornerTextView.setTextColor(Color.parseColor("#00ff00"));
        cornerTextView.setBgBackGround(Color.parseColor("#ffff00"));
        cornerTextView.setCorner(35,10,10,35);
        cornerTextView.afterOkInvalidate();

示例图片：

image.png