Android 小部件启动应用程序并检测到应用程序未找到

Question

我需要一个简单的主页小部件来启动外部应用程序（例如：whatsapp）。

在我的 MainActivity extends AppWidgetProvider (onUpdate) 中，我使用此代码创建一个挂起的意图，如果安装了该应用程序，它会很好地工作。

Intent intent = new Intent();
ComponentName cn = new ComponentName("com.whatsapp", "com.whatsapp.Main");
intent.setComponent(cn);

PendingIntent pending = PendingIntent.getActivity(context, 0, intent, 0);

RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.activity_main);
views.setOnClickPendingIntent(R.id.imageView, pending);

appWidgetManager.updateAppWidget(currentWidgetId, views);

在 (onReceive) 部分，我使用此代码检测应用程序是否已安装

 PackageManager pm = context.getPackageManager();

        List<ApplicationInfo> list = pm.getInstalledApplications(0);

        for (int aa = 0; aa < list.size(); aa++) {         
            if(list.get(aa).packageName.equals("com.whatsapp")){  
                 //app istalled
                noapp = 0;
            }
            else{
                //app not istalled
                noapp1 = 1;         
            }
        }         
    if(noapp1==1){
    Toast.makeText(context, "Whatsapp not installed", Toast.LENGTH_SHORT).show();
  }

我的问题是：此代码检测应用程序是否未安装并显示 Toast 消息，但仅在小部件第一次位于家中时显示。如果未安装应用程序，我需要在触摸图像视图时随时显示消息。请帮忙！

Karakuri 我试着应用你的建议。这是我在主要 activity 中的代码，用于将意图附加到 imageView：

public class MainActivity extends AppWidgetProvider{

public void onUpdate(Context context, AppWidgetManager appWidgetManager,
        int[] appWidgetIds) {
    for(int i=0; i<appWidgetIds.length; i++){
        int currentWidgetId = appWidgetIds[i];

        Intent intent = new Intent(LaunchExternalAppReceiver.ACTION);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0);

        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.activity_main);
        views.setOnClickPendingIntent(R.id.imageView, pendingIntent); 
        // Tell the AppWidgetManager to perform an update on the current App Widget
        appWidgetManager.updateAppWidget(currentWidgetId, views);

    }      
  }   
}

这是带有 BroadcastReceiver 的新 class（我将简单代码放入我的简单代码中以检查应用程序是否已安装，仅用于测试）：

public class LaunchExternalAppReceiver extends BroadcastReceiver {
public static final String ACTION = "control";

@Override
public void onReceive(Context context, Intent intent) {

    PackageManager pm = context.getPackageManager();

    List<ApplicationInfo> list = pm.getInstalledApplications(0);

    for (int aa = 0; aa < list.size(); aa++) {  

        if(list.get(aa).packageName.equals("com.whatsapp")){  
            //app istalled

        }
        else{
            //app not istalled             
            Toast.makeText(context, "Whatsapp not installed", Toast.LENGTH_SHORT).show();
        }
    }             
  }
}

这是我的清单：

 <uses-sdk
    android:minSdkVersion="11"
    android:targetSdkVersion="19" /><application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <receiver android:name=".MainActivity" >
        <intent-filter>
            <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
        </intent-filter>

        <meta-data
            android:name="android.appwidget.provider"
            android:resource="@xml/mywidget" />
    </receiver>
    <receiver android:name=".LaunchExternalAppReceiver" >
        <intent-filter>
            <action android:name="control" >
            </action>
        </intent-filter>
    </receiver>
</application>

非常感谢您的帮助。

Answer 1

点击 ImageView 向应用程序中的接收器发送广播（使用 PendingIntent.getBroadcast()）。在该接收器中，您可以检查是否安装了外部应用程序并从那里启动它。

编辑

创建一个新的 BroadcastReceiver。

public class LaunchExternalAppReceiver extends BroadcastRecevier {
    public static final String ACTION = "some-unique-string-here";

    @Override
    public void onReceive(Context context, Intent intent) {
        // check if the external app is installed and launch it
        PackageManager pm = context.getPackageManager();
        try {
            pm.getApplicationInfo("com.whatsapp", 0); // throws if not found
            Intent intent = pm.getLaunchIntentForPackage("com.whatsapp");
            if (intent != null) {
                context.startActivity(intent);
            }
        } catch (NameNotFoundException e) {
            // package not found, you can show the Toast here
        }
    }
}

将其添加到您的 AndroidManifest。确保 intent 过滤器操作与上面的 ACTION 匹配。

<receiver android:name=".LaunchExternalAppReceiver">
    <intent-filter>
        <action android:name="some-unique-string-here">
    </intent-filter>
</receiver>

使用此操作让您的 ImageView 发送广播，而不是尝试启动外部应用程序。

Intent intent = new Intent(LaunchExternalAppReceiver.ACTION);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
remoteViews.setOnClickPendingIntent(R.id.imageView, pendingIntent);

Answer 2

我找到了替代解决方案。工作迎接但有一个恼人的小问题。我在主 activity 的 imageView 上附加了一个意图，以在这个 class 中启动一个新的 class "control" 我检查是否安装了该应用程序并启动她或发送消息并提供下载按钮。问题是...如果安装了应用程序，控件 class 会启动她，但会在应用程序打开前出现 activity（控件）屏幕一秒钟。很烦人。有人可以帮助我进行最终修复吗？谢谢

在onUpdate（主要activity）中：

    Intent controlIntent = new Intent(context, Control.class);          
    PendingIntent pendingc1 = PendingIntent.getActivity(context, 0, controlIntent, 0);
    RemoteViews views1 = new RemoteViews(context.getPackageName(), R.layout.activity_main);
    views1.setOnClickPendingIntent(R.id.imageView, pendingc1);
    appWidgetManager.updateAppWidget(currentWidgetId, views1);

我的新class（对照）：

public class Control extends Activity {
private TextView testo;

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

    PackageManager pm = this.getPackageManager();

    List<ApplicationInfo> list = pm.getInstalledApplications(0);

    for (int aa = 0; aa < list.size(); aa++) {

        if (list.get(aa).packageName.equals("com.whatsapp")) {
            // app istalled

            Intent launchIntent = getPackageManager()
                    .getLaunchIntentForPackage("com.whatsapp");
            startActivity(launchIntent);
            Control.this.finish();

        } else {
            setContentView(R.layout.control);
            // app not istalled
            testo = (TextView) findViewById(R.id.message);
            String text = "WhatsApp is Not Installed\nPlease Download Whatsapp from Play Store";
            testo.setText(text);

            Button button = (Button) findViewById(R.id.exit);
            button.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {
                    Control.this.finish();
                }
            });

            Button button2 = (Button) findViewById(R.id.download);
            button2.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {
                    startActivity(new Intent(Intent.ACTION_VIEW, Uri
                            .parse("market://details?id=" + "com.whatsapp")));
                    Control.this.finish();
                }
            });

        }
    }
  }
}

Android 小部件启动应用程序并检测到应用程序未找到

Android widget launch App and detect App Not found

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