Android小部件启动应用程序和检测应用程序未找到

Question

我需要一个简单的家庭Widget来启动一个外部应用程序(例如: whatsapp)。

在我的MainActivity扩展AppWidgetProvider (onUpdate)中，我使用这段代码创建一个挂起的意图，如果安装了该应用程序，它的工作效果很好。

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)部分中，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:这段代码检测应用程序是否未安装并显示Toast消息，但只在小部件第一次定位在家中时才显示。如果没有安装App，我需要在触摸图像视图时显示消息。请帮帮忙！

卡拉库里我试着采纳你的建议。这是我在主要活动中的代码，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);

    }      
  }   
}

这是一个带有BroadcastReceiver的新类(我把简单的代码放在里面，以检查应用程序是否已经安装，只是为了测试)：

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();
        }
    }             
  }
}

这是我的宣言：

 <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>

非常感谢你的帮助。

Answer 1

我找到了另一种解决办法。工作打招呼，但有一个恼人的小问题。在我的主要活动中，我向imageView附加了一个意图，在这个类中启动一个新的类“控件”，我检查应用程序是否已经安装并启动她，或者发送消息并提供一个下载按钮。问题，is...if，应用程序安装，控制类，启动她，但第二次出现活动(控制)屏幕之前，应用程序打开。很烦人。有人能帮我做最后的修正吗？谢谢。

在onUpdate (主要活动)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); 

我的新班级(控制室)：

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();
                }
            });

        }
    }
  }
}

Answer 2

让ImageView点击将广播发送到应用程序中的接收器(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

做一个新的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AndroidManifest中。确保意图筛选器操作与上面的操作匹配。

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

让你的ImageView用这个动作发送广播，而不是试图启动外部应用程序。

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