陷入自定义view的坑越陷越深，励志要把自定义view撸给遍，今天给大家介绍一下自定义view————开关button，这个在很多app中都能用的，废话不多说，先来给动图。
分析一下上面的效果：四个状态：关闭状态、关闭->打开过程、打开状态、打开->关闭过程，结合ValueAnimator动效实现这个过程
关闭状态
绘制一个圆角矩形(drawRoundRect()方法)，再画一个圆(drawCircle())，默认关闭就画好了
RectF rectF = new RectF(padding, padding, mwidth - padding, mheight - padding);
//先画背景
canvas.drawRoundRect(rectF, backgroundRadius, backgroundRadius, closePaint);
//再画圆
canvas.drawCircle(closecenterX, closecenterY, circleRadius, circlePaint);复制代码打开状态
绘制了关闭状态，再绘制打开状态，，最后绘制关闭->打开状态，打开->关闭状态，其实这里和关闭状态类似的，只是画圆的x、y的位置不一样而已
RectF rectF = new RectF(padding, padding, mwidth - padding, mheight - padding);
//先画背景
canvas.drawRoundRect(rectF, backgroundRadius, backgroundRadius, closePaint);
RectF rectFAnimation = new RectF(padding, padding, o2cright, o2cbottom);
//先画背景
canvas.drawRoundRect(rectFAnimation, backgroundRadius, backgroundRadius, openPaint);
//再画圆
canvas.drawCircle(o2ccenterX, o2ccenterY, circleRadius, circlePaint);复制代码关闭->打开状态
ValueAnimator动效中的addUpdateListener()的回调通过valueAnimator.getAnimatedValue();来重新绘制过程，计算圆在状态变化时的x,y及其圆角矩形的right,bottom值来动态改变然后重新绘制。
记录动态的变化值
close2OpengvalueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
mclose2OpenAnimatorValue = (float) valueAnimator.getAnimatedValue();
//圆在状态变化时的x,y
c2ocenterX = closecenterX + closeOpenX * mclose2OpenAnimatorValue;
c2ocenterY = backgroundRadius + padding;
//背景的右下标=关闭状态的位置（2*backgroundRadius+padding）+差值*变化
c2oright = 2 * backgroundRadius + padding + closeOpenRight * mclose2OpenAnimatorValue;
//背景的底下标=关闭状态的位置（2*backgroundRadius+padding）+差值*变化
c2obottom = 2 * backgroundRadius + padding + closeOpenBottom * mclose2OpenAnimatorValue;
invalidate();
}
});
close2OpengvalueAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {
}
@Override
public void onAnimationEnd(Animator animator) {
setOpen();
invalidate();
}
@Override
public void onAnimationCancel(Animator animator) {
}
@Override
public void onAnimationRepeat(Animator animator) {
}
});复制代码根据变化值重新绘制
RectF rectF = new RectF(padding, padding, mwidth - padding, mheight - padding);
//先画背景
canvas.drawRoundRect(rectF, backgroundRadius, backgroundRadius, closePaint);
RectF rectFAnimation = new RectF(padding, padding, c2oright, c2obottom);
//先画背景
canvas.drawRoundRect(rectFAnimation, backgroundRadius, backgroundRadius, openPaint);
//再画圆
canvas.drawCircle(c2ocenterX, c2ocenterY, circleRadius, circlePaint);复制代码打开->关闭状态
这个动画状态和上面的动画状态同理
记录变化值
openg2ClosevalueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
mopeng2CloseAnimatorValue = (float) valueAnimator.getAnimatedValue();
//圆在状态变化时的x,y
o2ccenterX = closecenterX+closeOpenX * mopeng2CloseAnimatorValue;
o2ccenterY = backgroundRadius + padding;
//背景的右下标=关闭状态的位置（2*backgroundRadius+padding）+差值*变化
o2cright = 2 * backgroundRadius + padding + closeOpenRight * mopeng2CloseAnimatorValue;
//背景的底下标=关闭状态的位置（2*backgroundRadius+padding）+差值*变化
o2cbottom = 2 * backgroundRadius + padding + closeOpenBottom * mopeng2CloseAnimatorValue;
invalidate();
}
});
openg2ClosevalueAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {
}
@Override
public void onAnimationEnd(Animator animator) {
setClose();
invalidate();
}
@Override
public void onAnimationCancel(Animator animator) {
}
@Override
public void onAnimationRepeat(Animator animator) {
}
});复制代码根据变化值重新绘制
RectF rectF = new RectF(padding, padding, mwidth - padding, mheight - padding);
//先画背景
canvas.drawRoundRect(rectF, backgroundRadius, backgroundRadius, closePaint);
RectF rectFAnimation = new RectF(padding, padding, o2cright, o2cbottom);
//先画背景
canvas.drawRoundRect(rectFAnimation, backgroundRadius, backgroundRadius, openPaint);
//再画圆
canvas.drawCircle(o2ccenterX, o2ccenterY, circleRadius, circlePaint);复制代码上面的四种状态介绍完毕了,大致功能就实现了，接下来介绍一些属性的设置、四种状态设置的方法、点击事件等
四种状态的设置
/***
* 关闭
*/
private void setClose() {
mcurrentState = State.CLOSE;
invalidate();
}
/***
* 打开
*/
private void setOpen() {
mcurrentState = State.OPEN;
invalidate();
}
/***
* 关闭到打开
*/
private void setClose2Open() {
mcurrentState = State.CLOSE2OPEN;
openg2ClosevalueAnimator.removeAllUpdateListeners();
addCloseToOpenAnimator();
close2OpengvalueAnimator.start();
}
/***
* 打开到关闭
*/
private void setOpen2Close() {
mcurrentState = State.OPEN2CLOSE;
close2OpengvalueAnimator.removeAllUpdateListeners();
addOpenToCloseAnimator();
openg2ClosevalueAnimator.start();
}复制代码点击事件执行打开关闭
/***
* 控件点击执行该方法 改变状态
*/
public void onclick(){
if(mcurrentState==State.CLOSE){
setClose2Open();
}else if(mcurrentState==State.OPEN){
setOpen2Close();
}
}复制代码属性的设置
xml设置
attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="SwitchButton">
<attr name="backgroudColor" format="color"/>
<attr name="closeColor" format="color"/>
<attr name="openColor" format="color"/>
<attr name="circleColor" format="color"/>
<attr name="animatorTime" format="integer"/>
<attr name="padding" format="integer"/>
</declare-styleable>
</resources>复制代码 private void initTypeArray(Context context, AttributeSet attrs) {
TypedArray typedArray=context.obtainStyledAttributes(attrs,R.styleable.SwitchButton);
backgroudColor=typedArray.getColor(R.styleable.SwitchButton_backgroudColor,Color.WHITE);
closeColor=typedArray.getColor(R.styleable.SwitchButton_closeColor,Color.GRAY);
openColor=typedArray.getColor(R.styleable.SwitchButton_openColor,Color.GREEN);
circleColor=typedArray.getColor(R.styleable.SwitchButton_circleColor,Color.WHITE);
padding=typedArray.getInteger(R.styleable.SwitchButton_padding,1);
animatorTime=typedArray.getInteger(R.styleable.SwitchButton_animatorTime,500);
typedArray.recycle();
}复制代码xml中设置
<com.switchbutton.SwitchButton
android:id="@+id/btn1"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_marginTop="20dp"
app:closeColor="@color/colorAccent"
app:openColor="@android:color/holo_green_light"
app:padding="6"
app:animatorTime="1000"
/>复制代码代码设置
/**
* 设置背景颜色
* @param backgroudColor
*/
public void setBackgroudColor(int backgroudColor) {
this.backgroudColor = backgroudColor;
}
/**
* 关闭状态颜色
* @param closeColor
*/
public void setCloseColor(int closeColor) {
this.closeColor = closeColor;
closePaint.setColor(closeColor);
}
/**
* 打开状态颜色
* @param openColor
*/
public void setOpenColor(int openColor) {
this.openColor = openColor;
openPaint.setColor(openColor);
}
/**
* 圆的颜色
* @param circleColor
*/
public void setCircleColor(int circleColor) {
this.circleColor = circleColor;
circlePaint.setColor(circleColor);
}
/**
* 间距
* @param padding
*/
public void setPadding(int padding) {
this.padding = padding;
}
/**
* 动画时间
* @param animatorTime
*/
public void setAnimatorTime(int animatorTime) {
this.animatorTime = animatorTime;
}复制代码考虑实践应用中，需要获取相关状态，上传至服务器／根据状态设置相关设置等
/**
* 获取当前的状态 用于使用时的需求
* @return
*/
public State getMcurrentState() {
return mcurrentState;
}复制代码其他方法也可以实现，根据自己的需求去做相应的更改