清單文件必須添加

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
      ...
     <queries>
        <package android:name="com.whatsapp" />
        <package android:name="com.facebook.katana" />
        <package android:name="org.telegram.messenger" />
    </queries>
</manifest>

判斷App是否安裝

public static boolean isAppInstalled(Context context, String packageName) {
        PackageInfo packageInfo;
        try {
            packageInfo = context.getPackageManager().getPackageInfo(packageName, 0);
        } catch (PackageManager.NameNotFoundException e) {
            packageInfo = null;
            e.printStackTrace();
        }
        return packageInfo != null;
    }