通过whatsapp以编程方式发送消息

您可以使用这个想法很简单，您实际上将使Android执行Whatsapp的发送按钮的点击.

The idea is quite simple, you'll actually make Android perform the click on Whatsapp's send button.

因此流程将是:

1. 发送常规消息(具有您当前正在使用的意图)，并在消息内容的末尾添加后缀，例如"Sent by MY_APP".
2. 在此处输入文字后，将通知您的辅助功能服务whatsapp的EditText已填充.
3. 如果whatsapp的EditText上存在后缀，则您的可访问性服务将单击发送"按钮. (这是为了避免在用户自然键入常规消息时执行操作).

1. Send a regular message (with the intent you're currently using) with a suffix at the end of your message content such as "Sent by MY_APP".
2. Once the text there, your accessibility service will be notified that the EditText of whatsapp is filled.
3. If the suffix is present on the EditText of whatsapp, Your accessibility service will click on the send button. (this is to avoid performing actions as the user types in naturally a regular message).

这是一个示例(如果您想使其更具限制性，您将对其进行调整):

Here's an example (which you'll have tweak if you wanna make it more restrictive):

public class WhatsappAccessibilityService extends AccessibilityService {

    @Override
    public void onAccessibilityEvent (AccessibilityEvent event) {
        if (getRootInActiveWindow () == null) {
            return;
        }

        AccessibilityNodeInfoCompat rootInActiveWindow = AccessibilityNodeInfoCompat.wrap (getRootInActiveWindow ());

        // Whatsapp Message EditText id
        List<AccessibilityNodeInfoCompat> messageNodeList = rootInActiveWindow.findAccessibilityNodeInfosByViewId ("com.whatsapp:id/entry");
        if (messageNodeList == null || messageNodeList.isEmpty ()) {
            return;
        }

        // check if the whatsapp message EditText field is filled with text and ending with your suffix (explanation above)
        AccessibilityNodeInfoCompat messageField = messageNodeList.get (0);
        if (messageField.getText () == null || messageField.getText ().length () == 0 
            || !messageField.getText ().toString ().endsWith (getApplicationContext ().getString (R.string.whatsapp_suffix))) { // So your service doesn't process any message, but the ones ending your apps suffix
            return;
        }

        // Whatsapp send button id
        List<AccessibilityNodeInfoCompat> sendMessageNodeInfoList = rootInActiveWindow.findAccessibilityNodeInfosByViewId ("com.whatsapp:id/send");
        if (sendMessageNodeInfoList == null || sendMessageNodeInfoList.isEmpty ()) {
            return;
        }

        AccessibilityNodeInfoCompat sendMessageButton = sendMessageNodeInfoList.get (0);
        if (!sendMessageButton.isVisibleToUser ()) {
            return;
        }

        // Now fire a click on the send button
        sendMessageButton.performAction (AccessibilityNodeInfo.ACTION_CLICK);

        // Now go back to your app by clicking on the Android back button twice: 
        // First one to leave the conversation screen 
        // Second one to leave whatsapp
        try {
            Thread.sleep (500); // hack for certain devices in which the immediate back click is too fast to handle
            performGlobalAction (GLOBAL_ACTION_BACK);
            Thread.sleep (500);  // same hack as above
        } catch (InterruptedException ignored) {}
        performGlobalAction (GLOBAL_ACTION_BACK);
    }
}

然后在res -> xml -> whatsapp_service.xml中创建其定义:

<?xml version="1.0" encoding="utf-8"?>
<accessibility-service
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:accessibilityEventTypes="typeWindowContentChanged"
    android:packageNames="com.whatsapp"
    android:accessibilityFeedbackType="feedbackSpoken"
    android:notificationTimeout="100"
    android:canRetrieveWindowContent="true"/>

然后在清单中声明它:

<service
    android:name=".services.WhatsappAccessibilityService"
    android:label="Accessibility Service"
   android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
    <meta-data
        android:name="android.accessibilityservice"
        android:resource="@xml/whatsapp_service"/>

    <intent-filter>
        <action android:name="android.accessibilityservice.AccessibilityService"/>
    </intent-filter>
</service>

最后一件事是检查是否为您的应用程序启用了辅助功能，如果没有，则将用户重定向到设置:

And last thing, is to check if the accessibility services are enabled for your app or not, and redirect the user to the settings if not:

private boolean isAccessibilityOn (Context context, Class<? extends AccessibilityService> clazz) {
    int accessibilityEnabled = 0;
    final String service = context.getPackageName () + "/" + clazz.getCanonicalName ();
    try {
        accessibilityEnabled = Settings.Secure.getInt (context.getApplicationContext ().getContentResolver (), Settings.Secure.ACCESSIBILITY_ENABLED);
    } catch (Settings.SettingNotFoundException ignored) {  }

    TextUtils.SimpleStringSplitter colonSplitter = new TextUtils.SimpleStringSplitter (":");

    if (accessibilityEnabled == 1) {
        String settingValue = Settings.Secure.getString (context.getApplicationContext ().getContentResolver (), Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES);
        if (settingValue != null) {
            colonSplitter.setString (settingValue);
            while (colonSplitter.hasNext ()) {
                String accessibilityService = colonSplitter.next ();

                if (accessibilityService.equalsIgnoreCase (service)) {
                    return true;
                }
            }
        }
    }

    return false;
}

您将使用的呼叫方式:

if (!isAccessibilityOn (context, WhatsappAccessibilityService.class)) {
    Intent intent = new Intent (Settings.ACTION_ACCESSIBILITY_SETTINGS);
    context.startActivity (intent);
}

这纯粹是在解决方案的技术方面.

This is purely on the technical aspect of the solution.

现在，您应该这样做吗?" 的道德问题，我相信答案很明确:

Now, the ethical question of "should you do that?", I believe the answer is quite clear:

除非您以残疾人为对象(这是Accessibility API的目的)，否则您应该不这样做.

Except if you are targeting people with disabilities (which is the very purpose of the Accessibility API), you should probably NOT do that.