Question

在我的应用中，我有两个activities，它们看起来像两个不同的应用程序（主屏幕上的单独图标）给用户。现在他们都有一个intent-filter监听插入的USB设备。问题是，当我在Activity A并且我将USB设备插入平板电脑时，会自动启动Activity B。我想要实现的是：

Activity A -> insert USB -> stay in Activity A and do something with the USB
Activity B -> insert USB -> stay in Activity B and do something else with the USB

这是我的清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="mypackage.myapp"
    android:versionCode="100"
    android:versionName="1.0.0-dev" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="19" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/my_icon"
        android:theme="@style/AppTheme" >
        <activity
            android:name="mypackage.ActivityA"
            android:icon="@drawable/my_icon"
            android:label="@string/ActivityA"
            android:launchMode="singleTask"
            android:screenOrientation="landscape" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />

            </intent-filter>
            <meta-data
                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/lib_device_filter" />

        </activity>
        <activity
            android:name="mypackage.ActivityB"
            android:icon="@drawable/another_icon"
            android:label="@string/ActivityB"
            android:launchMode="singleTask"
            android:screenOrientation="landscape" >

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
            </intent-filter>
            <meta-data
                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/lib_device_filter" />

        </activity>
    </application>
</manifest>

Answer 1

我在项目中发现了同样的问题，我想与大家分享一下实施解决方案

首先，我做了一个名为DumpActivity的活动。此活动只是实现了意图过滤器，以便在USB插入时进行监听，这就是全部。当活动启动时，立即完成以返回上一个活动。此时，上一个活动（示例中的活动A或B）可以与USB进行交互。

/**
 * This activity have the intent filters of the USB (see AndroidManifest.xml).
 *
 * When it is the first time that the USB microphones are plugged, this activity is launched.
 * This is a solution to disable the popup dialog when a USB device is connected.
 *
 * When this activity is launched, immediately it is destroyed to return to the previous
 * activity
 */

public class DumpActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    protected void onStart() {
        super.onStart();
        if (getIntent().getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
            finish();
        }
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        if (intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
            finish();
        }
    }
 }

然后，在清单中：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="mypackage.myapp"
    android:versionCode="100"
    android:versionName="1.0.0-dev" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="19" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

    <uses-permission android:name="android.permission.USB_PERMISSION" />
    <uses-feature android:name="android.hardware.usb.host" />
    <uses-feature android:name="android.hardware.usb.accessory" />
    <uses-feature android:name="android.hardware.usb.device" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/my_icon"
        android:theme="@style/AppTheme" >
        <activity
            android:name="mypackage.DumpActivity"
            android:label="@string/app_name"
            android:launchMode="singleTask"
            android:screenOrientation="landscape"
            android:theme="@android:style/Theme.Black.NoTitleBar" >
            <intent-filter>
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
                <action android:name="android.hardware.usb.action.USB_DEVICE_DETTACHED" />
            </intent-filter>
            <meta-data
                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/lib_device_filter">
            </meta-data>
            <meta-data
                android:name="android.hardware.usb.action.USB_DEVICE_DETTACHED"
                android:resource="@xml/lib_device_filter">
            </meta-data>
        </activity>
        <activity
            android:name="mypackage.ActivityA"
            android:icon="@drawable/my_icon"
            android:label="@string/ActivityA"
            android:launchMode="singleTask"
            android:screenOrientation="landscape" >
        </activity>
        <activity
            android:name="mypackage.ActivityB"
            android:icon="@drawable/another_icon"
            android:label="@string/ActivityB"
            android:launchMode="singleTask"
            android:screenOrientation="landscape" >
        </activity>
    </application>
</manifest>

注意1：意图过滤器必须仅在此活动中！

注意2：如果您需要在不同的活动中与USB进行交互，并且每次插入USB时都不想看到弹出对话框，此解决方案非常有用。

Marc G。

针对不同的活动处理相同的intent-filter

1 个答案: