前奏:

在你的手机更多设置或者高级设置中，我们会发现有个无障碍的功能，很多人不知道这个功能具体是干嘛的，其实这个功能是为了增强用户界面以帮助残障人士，或者可能暂时无法与设备充分交互的人们

image.png

它的具体实现是通过AccessibilityService服务运行在后台中，通过AccessibilityEvent接收指定事件的回调。
例如：焦点改变了，一个按钮被点击，等等。这样的服务可以选择请求活动窗口的内容的能力。简单的说AccessibilityService就是一个后台监控服务，当你监控的内容发生改变时，就会调用后台服务的回调方法

AccessibilityService使用

1.1创建服务类

编写自己的Service类，重写onServiceConnected()方法、onAccessibilityEvent()方法和onInterrupt()方法

/**
 * Created by zxn on 2019/4/29.
 */
public class PlugAccessibilityService extends AccessibilityService {

    /**
     * 当启动服务的时候就会被调用,系统成功绑定该服务时被触发，也就是当你在设置中开启相应的服务，
     * 系统成功的绑定了该服务时会触发，通常我们可以在这里做一些初始化操作
     */
    @Override
    protected void onServiceConnected() {
        super.onServiceConnected();
    }

    /**
     * 通过系统监听窗口变化的回调,sendAccessibiliyEvent()不断的发送AccessibilityEvent到此处
     *
     * @param event
     */
    @Override
    public void onAccessibilityEvent(AccessibilityEvent event) {
        int eventType = event.getEventType();
        //根据时间回调类型进行处理.
    }

    /**
     * 中断服务时的回调.
     */
    @Override
    public void onInterrupt() {

    }

    /**
     * 查找拥有特定焦点类型的控件
     *
     * @param focus
     * @return
     */
    @Override
    public AccessibilityNodeInfo findFocus(int focus) {
        return super.findFocus(focus);
    }

    /**
     * 如果配置能够获取窗口内容,则会返回当前活动窗口的根结点
     *
     * @return
     */
    @Override
    public AccessibilityNodeInfo getRootInActiveWindow() {
        return super.getRootInActiveWindow();
    }


    /**
     * 获取系统服务
     *
     * @param name
     * @return
     */
    @Override
    public Object getSystemService(String name) {
        return super.getSystemService(name);
    }

    /**
     * 如果允许服务监听按键操作，该方法是按键事件的回调，需要注意，这个过程发生了系统处理按键事件之前
     *
     * @param event
     * @return
     */
    @Override
    protected boolean onKeyEvent(KeyEvent event) {
        return super.onKeyEvent(event);
    }
}

1.1.1AccessibilityService中常用的方法的介绍

• findFocus(int focus)
  查找拥有特定焦点类型的控件

• getRootInActiveWindow()
  如果配置能够获取窗口内容,则会返回当前活动窗口的根结点

• final void disableSelf()
  禁用当前服务，也就是在服务可以通过该方法停止运行

• final AccessibilityServiceInfo getServiceInfo()
  获取当前服务的配置信息

• onAccessibilityEvent(AccessibilityEvent event)
  有关AccessibilityEvent事件的回调函数，系统通过sendAccessibiliyEvent()不断的发送AccessibilityEvent到此处

• performGlobalAction(int action)
  执行全局操作，比如返回，回到主页，打开最近等操作

• setServiceInfo(AccessibilityServiceInfo info)
  设置当前服务的配置信息

• getSystemService(String name)
  获取系统服务

• onKeyEvent(KeyEvent event)
  如果允许服务监听按键操作，该方法是按键事件的回调，需要注意，这个过程发生了系统处理按键事件之前

• onServiceConnected()
  系统成功绑定该服务时被触发，也就是当你在设置中开启相应的服务，系统成功的绑定了该服务时会触发，通常我们可以在这里做一些初始化操作

• onInterrupt()
  服务中断时的回调

1.2 声明服务

在manifests中配置该服务信息

<service
    android:name=".PlugAccessibilityService"
    android:enabled="true"
    android:exported="true"
    android:label="@string/plug_name"
    android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
    <intent-filter>
        <action android:name="android.intent.action.RESPOND_VIA_MESSAGE" />
    </intent-filter>
</service>

注意：任何一个信息配置错误，都会使该服务无反应

• android:label：在无障碍列表中显示该服务的名字

  
  image.png

• android:permission：需要指定BIND_ACCESSIBILITY_SERVICE权限，这是4.0以上的系统要求的
• intent-filter：这个name是固定不变的

1.3 配置服务参数

配置服务参数是指：配置用来接受指定类型的事件，监听指定package，检索窗口内容，获取事件类型的时间等等。其配置服务参数有两种方法：

• 方法一：安卓4.0之后可以通过meta-data标签指定xml文件进行配置

• 方法二：通过代码动态配置参数

1.3.1 方法一

在原先的manifests中增加meta-data标签指定xml文件

<service
    android:name=".PlugAccessibilityService"
    android:enabled="true"
    android:exported="true"
    android:label="@string/plug_name"
    android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
    <intent-filter>
        <action android:name="android.intent.action.RESPOND_VIA_MESSAGE" />
    </intent-filter>

    <meta-data
        android:name="android.accessibilityservice"
        android:resource="@xml/accessibility_service_config"
        />
</service>

接下来是accessibility_service_config文件的配置

<?xml version="1.0" encoding="utf-8"?>
<accessibility-service xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:accessibilityEventTypes="typeAllMask"
    android:accessibilityFeedbackType="feedbackAllMask"
    android:accessibilityFlags="flagRequestFilterKeyEvents"
    android:canRequestFilterKeyEvents="true"
    android:canRetrieveWindowContent="true"
    android:notificationTimeout="100" />

下面是对xml参数的介绍
accessibilityEventTypes：表示该服务对界面中的哪些变化感兴趣，即哪些事件通知，比如窗口打开，滑动，焦点变化，长按等。具体的值可以在AccessibilityEvent类中查到，如typeAllMask表示接受所有的事件通知

accessibilityFeedbackType：表示反馈方式，比如是语音播放，还是震动

canRetrieveWindowContent：表示该服务能否访问活动窗口中的内容。也就是如果你希望在服务中获取窗体内容，则需要设置其值为true

description：对该无障碍功能的描述，具体体现在下图
notificationTimeout：接受事件的时间间隔，通常将其设置为100即可

packageNames：表示对该服务是用来监听哪个包的产生的事件

1.3.2 方法二

通过代码为我们的AccessibilityService配置AccessibilityServiceInfo信息

public void setAccessibilityServiceInfo() {
    String[] packageNames = {"com.tencent.mm"};
    AccessibilityServiceInfo accessibilityServiceInfo = new AccessibilityServiceInfo();
    //相应时间的类型,(长安,点击,滑动)
    accessibilityServiceInfo.eventTypes = AccessibilityEvent.TYPES_ALL_MASK;
    //反馈给用户的类型,这里是语音
    accessibilityServiceInfo.feedbackType = AccessibilityServiceInfo.FEEDBACK_SPOKEN;

    //过滤的包名
    accessibilityServiceInfo.packageNames = packageNames;
    setServiceInfo(accessibilityServiceInfo);
}

在这里涉及到了AccessibilityServiceInfo类，AccessibilityServiceInfo类被用于配置AccessibilityService信息，该类中包含了大量用于配置的常量字段及用来xml属性，常见的有：accessibilityEventTypes，canRequestFilterKeyEvents，packageNames等等

1.4 启动服务

这里我们需要在无障碍功能里面手动打开该项功能，否则无法继续进行，通过

下面代码可以打开系统的无障碍功能列表

Intent intent = new Intent(Settings.ACTION_ACCESSIBILITY_SETTINGS);
startActivity(intent);

1.5 处理事件信息

由于我们监听了事件的通知栏和界面等信息，当我们指定packageNames的通知栏或者界面发生变化时，会通过onAccessibilityEvent回调我们的事件，接着进行事件的处理

@Override
public void onAccessibilityEvent(AccessibilityEvent event) {
    int eventType = event.getEventType();
    //根据时间回调类型进行处理.
    switch (eventType) {
        //通知栏变化时
        case AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED:
            break;
        case AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED:
            //当窗口状态发生改变时.
            break;
    }
}

当我们微信收到通知时，状态栏会有一条推送信息到达，这个时候就会被TYPE_NOTIFICATION_STATE_CHANGED监听，执行里面的内容，当我们切换微信界面时，或者使用微信时，这个时候就会被TYPE_WINDOW_STATE_CHANGED监听，执行里面的内容

AccessibilityEvent的方法

getEventType()：事件类型

getSource()：获取事件源对应的结点信息

getClassName()：获取事件源对应类的类型，比如点击事件是有某个Button产生的，那么此时获取的就是Button的完整类名

getText()：获取事件源的文本信息，比如事件是有TextView发出的,此时获取的就是TextView的text属性。如果该事件源是树结构，那么此时获取的是这个树上所有具有text属性的值的集合

isEnabled()：事件源(对应的界面控件)是否处在可用状态

getItemCount()：如果事件源是树结构，将返回该树根节点下子节点的数量

1.6 获取节点信息

AccessibilityNodeInfo nodeInfo = getRootInActiveWindow();

1.6.2 获取指定子节点（控件节点）

//通过文本找到对应节点集合.
AccessibilityNodeInfo nodeInfo = getRootInActiveWindow();

List<AccessibilityNodeInfo> textList = nodeInfo.findAccessibilityNodeInfosByText("");

//通过空间id找到对应的节点集合.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
    List<AccessibilityNodeInfo> textIdList = nodeInfo.findAccessibilityNodeInfosByViewId("000");
}

1.7 模拟节点点击

当我们获取了节点信息之后，对控件节点进行模拟点击、长按等操作，AccessibilityNodeInfo类提供了performAction()方法让我们执行模拟操作，具体操作可看官方文档介绍，这里列举常用的操作

//模拟点击
nodeInfo.performAction(AccessibilityNodeInfo.ACTION_CLICK);
//模拟长安
nodeInfo.performAction(AccessibilityNodeInfo.ACTION_LONG_CLICK);
//模拟获取焦点
nodeInfo.performAction(AccessibilityNodeInfo.ACTION_FOCUS);
//模拟粘贴.
nodeInfo.performAction(AccessibilityNodeInfo.ACTION_PASTE);

监听控件插件实现

2.1 原理分析

2.2 注意事项

1,每个版本的按钮ID都是不一样的，在我们的程序中是需要去修改按钮ID，以达到版本的适配
2,在获取控件ID的时候，注意其布局是否可点击，否则获取不可点击的控件，会使程序无反应

2.3 获取控件ID

当我们手机接入USB线时，在Android Device Monitor中的选择设备并开启Dump View Hierarchy for UI Automator工具，通过它可以获取控件信息
monitor的安装目录.
C:\ZxnProgram\Android\Sdk\tools\monitor.bat

image.png

2.4 代码实现

科迈赢钱

包名:
com.pos.kmretailpos.mini
id:

com.pos.kmretailpos.mini:id/tv_waipay
com.pos.kmretailpos.mini:id/et_ys

科迈赢钱

包名:
com.pos.kmretailpos.mini
id:

com.pos.kmretailpos.mini:id/tv_waipay
com.pos.kmretailpos.mini:id/et_ys

AccessibilityEvent时间类型:

 /**
 * View被点击--->1
 * Represents the event of clicking on a {@link android.view.View} like
 * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.
 */
public static final int TYPE_VIEW_CLICKED = 0x00000001;

/**
 * View被长按
 * Represents the event of long clicking on a {@link android.view.View} like
 * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.
 */
public static final int TYPE_VIEW_LONG_CLICKED = 0x00000002;

/**
 * View被选中
 * Represents the event of selecting an item usually in the context of an
 * {@link android.widget.AdapterView}.
 */
public static final int TYPE_VIEW_SELECTED = 0x00000004;

/**
 * View获得焦点
 * Represents the event of setting input focus of a {@link android.view.View}.
 */
public static final int TYPE_VIEW_FOCUSED = 0x00000008;

/**
 * View文本变化
 * Represents the event of changing the text of an {@link android.widget.EditText}.
 */
public static final int TYPE_VIEW_TEXT_CHANGED = 0x00000010;

/**
 * 监听窗口状态变化，比如打开一个popupWindow，dialog，Activity切换等等.打开了一个PopupWindow，Menu或Dialog(--->32)
 * Represents the event of a change to a visually distinct section of the user interface.
 * These events should only be dispatched from {@link android.view.View}s that have
 * accessibility pane titles, and replaces {@link #TYPE_WINDOW_CONTENT_CHANGED} for those
 * sources. Details about the change are available from {@link #getContentChangeTypes()}.
 */
public static final int TYPE_WINDOW_STATE_CHANGED = 0x00000020;

/**
 * Notification通知变化
 * Represents the event showing a {@link android.app.Notification}.
 */
public static final int TYPE_NOTIFICATION_STATE_CHANGED = 0x00000040;

/**
 * 一个View进入悬停
 * Represents the event of a hover enter over a {@link android.view.View}.
 */
public static final int TYPE_VIEW_HOVER_ENTER = 0x00000080;

/**
 *  一个View退出悬停
 * Represents the event of a hover exit over a {@link android.view.View}.
 */
public static final int TYPE_VIEW_HOVER_EXIT = 0x00000100;

/**
 * 触摸浏览事件开始
 * Represents the event of starting a touch exploration gesture.
 */
public static final int TYPE_TOUCH_EXPLORATION_GESTURE_START = 0x00000200;

/**
 * 触摸浏览事件完成
 * Represents the event of ending a touch exploration gesture.
 */
public static final int TYPE_TOUCH_EXPLORATION_GESTURE_END = 0x00000400;

/**
 * 窗口的内容发生变化，或子树根布局发生变化(--->2048)
 * Represents the event of changing the content of a window and more
 * specifically the sub-tree rooted at the event's source.
 */
public static final int TYPE_WINDOW_CONTENT_CHANGED = 0x00000800;

/**
 *  View滚动
 * Represents the event of scrolling a view. This event type is generally not sent directly.
 * @see View#onScrollChanged(int, int, int, int)
 */
public static final int TYPE_VIEW_SCROLLED = 0x00001000;

/**
 *  Edittext文字选中发生改变事件
 * Represents the event of changing the selection in an {@link android.widget.EditText}.
 */
public static final int TYPE_VIEW_TEXT_SELECTION_CHANGED = 0x00002000;

/**
 * 应用产生一个通知事件
 * Represents the event of an application making an announcement.
 */
public static final int TYPE_ANNOUNCEMENT = 0x00004000;

/**
 * 获得无障碍焦点事件
 * Represents the event of gaining accessibility focus.
 */
public static final int TYPE_VIEW_ACCESSIBILITY_FOCUSED = 0x00008000;

/**
 * 无障碍焦点事件清除
 * Represents the event of clearing accessibility focus.
 */
public static final int TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED = 0x00010000;

/**
 *  在给定的移动粒度下遍历视图文本的事件
 * Represents the event of traversing the text of a view at a given movement granularity.
 */
public static final int TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY = 0x00020000;

/**
 *  开始手势监测
 * Represents the event of beginning gesture detection.
 */
public static final int TYPE_GESTURE_DETECTION_START = 0x00040000;

/**
 * 结束手势监测
 * Represents the event of ending gesture detection.
 */
public static final int TYPE_GESTURE_DETECTION_END = 0x00080000;

/**
 *  触摸屏幕事件开始
 * Represents the event of the user starting to touch the screen.
 */
public static final int TYPE_TOUCH_INTERACTION_START = 0x00100000;

/**
 * 触摸屏幕事件结束
 * Represents the event of the user ending to touch the screen.
 */
public static final int TYPE_TOUCH_INTERACTION_END = 0x00200000;

/**
 * 屏幕上的窗口变化事件，需要API 21+
 * Represents the event change in the system windows shown on the screen. This event type should
 * only be dispatched by the system.
 */
public static final int TYPE_WINDOWS_CHANGED = 0x00400000;

/**
 * View中的上下文点击事件
 * Represents the event of a context click on a {@link android.view.View}.
 */
public static final int TYPE_VIEW_CONTEXT_CLICKED = 0x00800000;

/**
 * 辅助用户读取当前屏幕事件
 * Represents the event of the assistant currently reading the users screen context.
 */
public static final int TYPE_ASSIST_READING_CONTEXT = 0x01000000;

/**
 * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
 * The type of change is not defined.
 */
public static final int CONTENT_CHANGE_TYPE_UNDEFINED = 0x00000000;

/**
 * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
 * One or more content changes occurred in the the subtree rooted at the source node,
 * or the subtree's structure changed when a node was added or removed.
 */
public static final int CONTENT_CHANGE_TYPE_SUBTREE = 0x00000001;

/**
 * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
 * The node's text changed.
 */
public static final int CONTENT_CHANGE_TYPE_TEXT = 0x00000002;

/**
 * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
 * The node's content description changed.
 */
public static final int CONTENT_CHANGE_TYPE_CONTENT_DESCRIPTION = 0x00000004;

/**
 * Change type for {@link #TYPE_WINDOW_STATE_CHANGED} event:
 * The node's pane title changed.
 */
public static final int CONTENT_CHANGE_TYPE_PANE_TITLE = 0x00000008;

/**
 * Change type for {@link #TYPE_WINDOW_STATE_CHANGED} event:
 * The node has a pane title, and either just appeared or just was assigned a title when it
 * had none before.
 */
public static final int CONTENT_CHANGE_TYPE_PANE_APPEARED = 0x00000010;

/**
 *
 * Change type for {@link #TYPE_WINDOW_STATE_CHANGED} event:
 * Can mean one of two slightly different things. The primary meaning is that the node has
 * a pane title, and was removed from the node hierarchy. It will also be sent if the pane
 * title is set to {@code null} after it contained a title.
 * No source will be returned if the node is no longer on the screen. To make the change more
 * clear for the user, the first entry in {@link #getText()} will return the value that would
 * have been returned by {@code getSource().getPaneTitle()}.
 */
public static final int CONTENT_CHANGE_TYPE_PANE_DISAPPEARED = 0x00000020;

/**
 * 一个窗口被添加了
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window was added.
 */
public static final int WINDOWS_CHANGE_ADDED = 0x00000001;

/**
 * 一个被窗口移除了.
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * A window was removed.
 */
public static final int WINDOWS_CHANGE_REMOVED = 0x00000002;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's title changed.
 */
public static final int WINDOWS_CHANGE_TITLE = 0x00000004;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's bounds changed.
 */
public static final int WINDOWS_CHANGE_BOUNDS = 0x00000008;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's layer changed.
 */
public static final int WINDOWS_CHANGE_LAYER = 0x00000010;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's {@link AccessibilityWindowInfo#isActive()} changed.
 */
public static final int WINDOWS_CHANGE_ACTIVE = 0x00000020;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's {@link AccessibilityWindowInfo#isFocused()} changed.
 */
public static final int WINDOWS_CHANGE_FOCUSED = 0x00000040;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's {@link AccessibilityWindowInfo#isAccessibilityFocused()} changed.
 */
public static final int WINDOWS_CHANGE_ACCESSIBILITY_FOCUSED = 0x00000080;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's parent changed.
 */
public static final int WINDOWS_CHANGE_PARENT = 0x00000100;

/**
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window's children changed.
 */
public static final int WINDOWS_CHANGE_CHILDREN = 0x00000200;

/**
 *
 * Change type for {@link #TYPE_WINDOWS_CHANGED} event:
 * The window either entered or exited picture-in-picture mode.
 */
public static final int WINDOWS_CHANGE_PIP = 0x00000400;