效果图：
定义一个类，取名为MySwitch.java，此类去继承View，为何是继承View而不是去继承ViewGroup呢，是因为自定义开关没有子控件，之需要操作自身绘制即可
package custom.view.upgrade.my_switch; import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View; import custom.view.R; public class MySwitch extends View implements View.OnClickListener { private static String TAG = MySwitch.class.getSimpleName(); private Paint mPaint; /**
* 让布局中来指定实例化，得到属性集合AttributeSet
* @param context
* @param attrs
*/
public MySwitch(Context context, @Nullable AttributeSet attrs) {
super(context, attrs); initView(context, attrs);
initListener();
} // 定义按钮背景图片
private Bitmap bmSwitchBackground; // 定义按钮拖动的图片
private Bitmap bmSwitchDrag; // 定义开关的状态 true || false , 默认是关闭状态
private boolean switchStatus; // 定义开关的临时记录状态
private boolean tempSwitchStatus; // 定义按钮拖动距离左边的距离
private int dragLife = -1; /**
* 初始化工作
*/
private void initView(Context context, AttributeSet attrs) {
mPaint = new Paint();
mPaint.setAntiAlias(true); // 抗锯齿 // 获取属性
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MySwitch);
bmSwitchBackground = ((BitmapDrawable) typedArray.getDrawable(R.styleable.MySwitch_switch_background)).getBitmap();
bmSwitchDrag = ((BitmapDrawable) typedArray.getDrawable(R.styleable.MySwitch_switch_drag)).getBitmap();
switchStatus = typedArray.getBoolean(R.styleable.MySwitch_switch_status, false);
} public void setBmSwitchBackground(int switchBackground) {
this.bmSwitchBackground = BitmapFactory.decodeResource(getResources() ,switchBackground);
} public void setBmSwitchDrag(int switchDrag) {
this.bmSwitchDrag = BitmapFactory.decodeResource(getResources(), switchDrag);
} public void setSwitChStatus(boolean switchStatus) {
this.switchStatus = switchStatus;
dragLife = -1;
} /**
* 初始化事件
*/
private void initListener() {
setOnClickListener(this);
} @Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec); // 宽度是：按钮背景的宽度
// 高度是：按钮背景的高度
// 测量自身View
setMeasuredDimension(bmSwitchBackground.getWidth(), bmSwitchBackground.getHeight());
} @Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas); // 绘制按钮背景
canvas.drawBitmap(bmSwitchBackground, 0, 0, mPaint); if (dragLife != -1) {
canvas.drawBitmap(bmSwitchDrag, dragLife, 0 , mPaint);
} else if (dragLife == -1) {
if (switchStatus) {
// 打开状态
// 滑动点向右就是开启状态
int openDragLife = getLifeDragMaxValue();
canvas.drawBitmap(bmSwitchDrag, openDragLife, 0, mPaint);
moveEndX = openDragLife;
} else {
// 关闭状态
canvas.drawBitmap(bmSwitchDrag, 0, 0, mPaint);
moveEndX = 0;
} // 当开关的状态发生变化后，回调方法告诉用户，开关改变了
if (null != onSwitchChangeListener && switchStatusChange) {
if (tempSwitchStatus != switchStatus) {
onSwitchChangeListener.onSwitchChange(switchStatus);
}
}
}
} private float downX;
private int moveEndX; private float clickDown;
private float clickMove; // 开关状态是否发送了改变
private boolean switchStatusChange; @Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event); // 必须要调用此方法，onClick点击事件方法才会生效
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
downX = event.getX();
isClick = true;
clickDown = event.getX();
switchStatusChange = false;
tempSwitchStatus = switchStatus;
break;
case MotionEvent.ACTION_MOVE:
// Log.d(TAG, ">>>>>不加等于：" + (int) (event.getX() - downX));
moveEndX += (int) (event.getX() - downX);
Log.d(TAG,">>>>>>加等于：" + moveEndX); if (moveEndX > getLifeDragMaxValue()) {
moveEndX = getLifeDragMaxValue();
} else if (moveEndX < 0){
moveEndX = 0;
} dragLife = moveEndX;
invalidate(); downX = event.getX(); clickMove = downX;
if (Math.abs(clickMove - clickDown) > 5) {
isClick = false;
} break;
case MotionEvent.ACTION_UP:
if (dragLife > (getLifeDragMaxValue() / 2)) {
dragLife = -1;
switchStatus = true;
switchStatusChange = true;
} else if (dragLife >= 0){
dragLife = -1;
switchStatus = false;
switchStatusChange = true;
} else {
switchStatusChange = false;
}
invalidate();
// upX = (int) event.getX();
break;
default:
break;
}
return true;
} private int getLifeDragMaxValue() {
return bmSwitchBackground.getWidth() - bmSwitchDrag.getWidth();
} /*@Override
protected void onFinishInflate() {
super.onFinishInflate(); if (switchStatus) {
moveEndX = getLifeDragMaxValue();
Log.d(TAG, ">>>>>>>>>>>>>>>>>onFinishInflate()............ getLifeDragMaxValue():" + getLifeDragMaxValue());
}
}*/ /**
* 定义点击事件状态
*/
private boolean isClick = true; @Override
public void onClick(View v) {
Log.d(TAG, "onClick() isClick:" + isClick);
if (isClick) {
if (switchStatus) {
switchStatus = false;
switchStatusChange = true;
} else {
switchStatus = true;
switchStatusChange = true;
}
// switchStatus = (switchStatus==true?false:true);
dragLife = -1;
invalidate();
}
} private OnSwitchChangeListener onSwitchChangeListener; /**
* 用户设置的 状态监听
* @param onSwitchChangeListener
*/
public void setOnSwitchChangeListener(OnSwitchChangeListener onSwitchChangeListener) {
this.onSwitchChangeListener = onSwitchChangeListener;
}
}
布局文件中去引用写好的自定义开关类
并设置自定义属性：
myswitch:switch_background="@mipmap/switch_background"
myswitch:switch_drag="@mipmap/switch_drag"
myswitch:switch_status="true"
<!-- 自定义开关升级版 -->
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:myswitch="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".upgrade.MainActivity"> <!-- 使用wrap_content，是因为不知道按钮的背景有多大，更加按钮图片的改变而变化 -->
<custom.view.upgrade.my_switch.MySwitch
android:id="@+id/custom_myswitch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
myswitch:switch_background="@mipmap/switch_background"
myswitch:switch_drag="@mipmap/switch_drag"
myswitch:switch_status="true"
/> </RelativeLayout>
自定义规则arrts.xml文件声明：
<?xml version="1.0" encoding="utf-8"?>
<resources> <declare-styleable name="MySwitch"> <attr name="switch_status" format="boolean" /> <attr name="switch_background" format="reference" /> <attr name="switch_drag" format="reference" /> </declare-styleable> </resources>
模拟用户来使用：
MySwitch mySwitch = findViewById(R.id.custom_myswitch);
// 设置开关的背景图片
mySwitch.setBmSwitchBackground(R.mipmap.switch_background);
// 设置开关拖动的图片
mySwitch.setBmSwitchDrag(R.mipmap.switch_drag);
// 设置开关的状态，打开、关闭
mySwitch.setSwitChStatus(false);
mySwitch.setOnSwitchChangeListener(new OnSwitchChangeListener() {
@Override
public void onSwitchChange(boolean switchChangeStatus) {
String result;
if (switchChangeStatus) {
result = "打开";
} else {
result = "关闭";
}
Toast.makeText(MainActivity.this, "开关已" + result, Toast.LENGTH_SHORT).show();
}
});