android开发仿IOS滑动开关

请尊重他人的劳动成果，转载请注明出处：http://blog.csdn.net/sw950729/article/details/52574050
抱歉，最近一直在玩~，博客也不知道写点什么好。落下了点，后期会更上。

android与ios相比，ios好多控件都是自带的，而android需要使用自定义来实现。今天说的是ios的滑动开关，我层看到好多博客都是通过自定义ToggleButton实现的。这里我通过自定义view来实现他的效果。
首先在onsizechange里把2个半圆和一个矩形绘制出来。

        width = w;        height = h;        left = top = 0;        right = width;        bottom = height * 0.8f;        cx = (right + left) / 2;        cy = (bottom + top) / 2;        RectF rectF = new RectF(left, top, bottom, bottom);        path.arcTo(rectF, 90, 180);        rectF.left = right - bottom;        rectF.right = right;        path.arcTo(rectF, 270, 180);        path.close();        circle_left = 0;        circle_right = bottom;        circle_width = circle_right - circle_left;        float circle_height = (bottom - top) / 2;        radius = circle_height * 0.9f;        borderwidth = (int) (2 * (circle_height - radius));        circle_cx = width - circle_height;

剩下的就是ondraw方法来绘制颜色，以及切换的效果。

 protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        paint.setStyle(Style.FILL);        paint.setAntiAlias(true);        canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG));        if (isChoose) {            paint.setColor(onColor);        } else {            paint.setColor(offColor);        }        canvas.drawPath(path, paint);        isAnimation = isAnimation - 0.1f > 0 ? isAnimation - 0.1f : 0;        //缩放大小参数随isAnimation变化而变化        final float scale = 0.98f * (isChoose ? isAnimation : 1 - isAnimation);        //保存canvas状态        canvas.save();        canvas.scale(scale, scale, circle_cx, cy);        paint.setColor(offColor);        canvas.drawPath(path, paint);        canvas.restore();        paint.reset();        float bTranslateX = width - circle_width;        final float translate = bTranslateX * (isChoose ? 1 - isAnimation : isAnimation);        canvas.translate(translate, 0);        if (isAnimation > 0) {            invalidate();        }        canvas.save();        paint.setStyle(Style.FILL);        paint.setColor(offColor);        canvas.drawCircle(circle_width / 2, circle_width / 2, radius, paint); // 按钮白底        paint.setStyle(Style.STROKE);        paint.setColor(borderColor);        paint.setStrokeWidth(borderwidth);        canvas.drawCircle(circle_width / 2, circle_width / 2, radius, paint); // 按钮灰边        canvas.restore();    }

最后我们在ontouch里面去改变他的状态：

    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()) {            case MotionEvent.ACTION_DOWN:                return true;            case MotionEvent.ACTION_CANCEL:                return true;            case MotionEvent.ACTION_UP:                    isAnimation = 1;                    isChoose = !isChoose;                    listener.onStateChanged(isChoose);                    invalidate();                break;        }        return super.onTouchEvent(event);    }

好了一个简单的ToggleButton就实现了，我的android交流群：232748032。欢迎进入。