Android開發中AccessibilityService的使用

AccessibilityService在官網上的介紹如下：

An accessibility service runs in the background and receives callbacks by the system when AccessibilityEvents are fired. Such events denote some state transition in the user interface, for example, the focus has changed, a button has been clicked, etc. Such a service can optionally request the capability for querying the content of the active window. Development of an accessibility service requires extending this class and implementing its abstract methods.

大致的意思是它是一個運行在後臺的服務，並且能夠接受到系統和用戶之間的交互信息，如按鈕的點擊，焦點變化等，它的主要功能如下：

一、獲取當前UI信息

二、監聽event（用戶的操作）

三、響應控件

我個人覺得以上三點其實和uiautomator非常像，一和三這兩點其實就是一個腳本工具的基本功能了，當然，uiautomator的會簡單而且容易上手，但AccessibilityService的速度也要比uiautomator，而且功能也更全，比如用AccessibilityService去寫搶紅包就會比uiautomator更合適。

好了，廢話不多說，這篇先說說AccessibilityService的使用。

1、聲明

需要在 AndroidManifest.xml 中聲明一個Service, 但是需要配置intent-filter爲android.accessibilityservice.AccessibilityService，還需要添加BIND_ACCESSIBILTY_SERVICE的權限

<service
            android:name=".MyAccessibilityService"
            android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
            <intent-filter>
                <action android:name="android.accessibilityservice.AccessibilityService" />
            </intent-filter>
            <meta-data
                android:name="android.accessibilityservice"
                android:resource="@xml/accessibility" />
        </service>

2、配置

用來指定輔助事件的類型，以及監聽包名等。

有兩種方式，一種是通過xml來指定，這種方式需要在Service中添加meta-data屬性

<?xml version="1.0" encoding="UTF-8"?>
<accessibility-service xmlns:android="http://schemas.android.com/apk/res/android"
    android:accessibilityEventTypes="typeViewClicked|typeViewFocused"
    android:accessibilityFeedbackType="feedbackSpoken"
    android:canRetrieveWindowContent="true"
    android:notificationTimeout="100" />

還有一種方式是通過setServiceInfo方法去配置，一般都會在onServiceConneted（在服務連接成功的時候調用）方法中去調用它。如：

<pre name="code" class="java">@Override
    protected void onServiceConnected() {
        Log.i(TAG, "config success!");
        AccessibilityServiceInfo accessibilityServiceInfo = new AccessibilityServiceInfo();
        //指定包名
        accessibilityServiceInfo.packageNames = PACKAGES;
        //指定事件類型
        accessibilityServiceInfo.eventTypes = AccessibilityEvent.TYPES_ALL_MASK;
        accessibilityServiceInfo.feedbackType = AccessibilityServiceInfo.FEEDBACK_SPOKEN;
        accessibilityServiceInfo.notificationTimeout = 1000;
        setServiceInfo(accessibilityServiceInfo);
    }

3、編寫輔助Service

import android.accessibilityservice.AccessibilityService;
import android.accessibilityservice.AccessibilityServiceInfo;
import android.util.Log;
import android.view.accessibility.AccessibilityEvent;

public class MyAccessibilityService extends AccessibilityService {
    private static final String TAG = MyAccessibilityService.class.getName();
    private String[] PACKAGES = {"com.android.mms"};

    public MyAccessibilityService() {
    }

    @Override
    protected void onServiceConnected() {
        Log.i(TAG, "config success!");
        AccessibilityServiceInfo accessibilityServiceInfo = new AccessibilityServiceInfo();
        //指定包名
        accessibilityServiceInfo.packageNames = PACKAGES;
        //指定事件類型
        accessibilityServiceInfo.eventTypes = AccessibilityEvent.TYPES_ALL_MASK;
        accessibilityServiceInfo.feedbackType = AccessibilityServiceInfo.FEEDBACK_SPOKEN;
        accessibilityServiceInfo.notificationTimeout = 1000;
        setServiceInfo(accessibilityServiceInfo);
    }

    @Override
    public void onAccessibilityEvent(AccessibilityEvent event) {
        int eventType = event.getEventType();
        String eventText = "";
        Log.i(TAG, "==============Start====================");
        switch (eventType) {
            case AccessibilityEvent.TYPE_VIEW_CLICKED:
                eventText = "TYPE_VIEW_CLICKED";
                break;
            case AccessibilityEvent.TYPE_VIEW_FOCUSED:
                eventText = "TYPE_VIEW_FOCUSED";
                break;
            case AccessibilityEvent.TYPE_VIEW_LONG_CLICKED:
                eventText = "TYPE_VIEW_LONG_CLICKED";
                break;
            case AccessibilityEvent.TYPE_VIEW_SELECTED:
                eventText = "TYPE_VIEW_SELECTED";
                break;
            case AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED:
                eventText = "TYPE_VIEW_TEXT_CHANGED";
                break;
            case AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED:
                eventText = "TYPE_WINDOW_STATE_CHANGED";
                break;
            case AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED:
                eventText = "TYPE_NOTIFICATION_STATE_CHANGED";
                break;
            case AccessibilityEvent.TYPE_TOUCH_EXPLORATION_GESTURE_END:
                eventText = "TYPE_TOUCH_EXPLORATION_GESTURE_END";
                break;
            case AccessibilityEvent.TYPE_ANNOUNCEMENT:
                eventText = "TYPE_ANNOUNCEMENT";
                break;
            case AccessibilityEvent.TYPE_TOUCH_EXPLORATION_GESTURE_START:
                eventText = "TYPE_TOUCH_EXPLORATION_GESTURE_START";
                break;
            case AccessibilityEvent.TYPE_VIEW_HOVER_ENTER:
                eventText = "TYPE_VIEW_HOVER_ENTER";
                break;
            case AccessibilityEvent.TYPE_VIEW_HOVER_EXIT:
                eventText = "TYPE_VIEW_HOVER_EXIT";
                break;
            case AccessibilityEvent.TYPE_VIEW_SCROLLED:
                eventText = "TYPE_VIEW_SCROLLED";
                break;
            case AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED:
                eventText = "TYPE_VIEW_TEXT_SELECTION_CHANGED";
                break;
            case AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED:
                eventText = "TYPE_WINDOW_CONTENT_CHANGED";
                break;
        }
        eventText = eventText + ":" + eventType;
        Log.i(TAG, eventText);
        Log.i(TAG, "=============END=====================");
    }

    @Override
    public void onInterrupt() {

    }


}

最後，在設置--輔助功能中 將對應的service開啓即可，這個例子是用來監聽信息應用的。