Android--SearchView效果

SearchView.gif

首先初始化一些参数

    //线的颜色
    private int strokeColor;
    private Paint mPaint = new Paint();
    //扇形圆的中心和要画的角度,圆的半径
    private float centerX, centerY, angle, radius;
    //记录动画进度
    private float radtio;
    //下划线长度
    private float lineWidth;

    public void init() {
        mPaint.setAntiAlias(true);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setColor(strokeColor);
        mPaint.setStrokeWidth(10);
        mPaint.setStrokeCap(Paint.Cap.ROUND);

        radius = 50;
        angle = 360;
        lineWidth = 500;
    }

在onDraw方法中做处理，要注意的是，我们要利用画布的旋转来画图形，可以免去很多计算

   @Override
    protected void onDraw(Canvas canvas) {
        centerX = canvas.getWidth() / 3.0f * 2;
        centerY = canvas.getHeight() / 3.0f;

        canvas.save();
        canvas.rotate(45, centerX, centerY);
        //画搜索图标的圆，在动画0-0.5内角度变为0，圆心平移radius
        if (radtio <= 0.5f) {
            RectF rectF = new RectF(centerX - radius + radius * radtio * 2, centerY - radius, centerX + radius + radius * radtio * 2, centerY + radius);
            canvas.drawArc(rectF, 0, angle * (1 - radtio * 2), false, mPaint);
        }
        //画搜索图标的线,在动画0-1内长度变为0
        Path path = new Path();
        path.moveTo(centerX + radius + radius * radtio * 2, centerY);
        path.lineTo(centerX + radius * 3, centerY);
        canvas.drawPath(path, mPaint);

        canvas.save();
        canvas.rotate(-45, centerX + radius * 3, centerY);
        //画搜索图标的下划线
        Path bootomPath = new Path();
        bootomPath.moveTo(centerX + radius * 3, centerY);
        bootomPath.lineTo(centerX + radius * 3 - lineWidth * radtio, centerY);
        canvas.drawPath(bootomPath, mPaint);

        canvas.restore();
        canvas.restore();

    }

项目地址：https://gitee.com/aruba/CanvasApplication.git