從packageName獲取ApplicationName

Question

我試圖插入應用程序的名稱作為首選項的摘要。 我寫了這段代碼，但是它不起作用，因為當我運行應用程序時，在此行中出現NullPointerException崩潰

name.setSummary(Pm.getApplicationLabel(nameApp));

代碼是

    value2 = getIntent().getStringExtra("ApplicationName");

    PackageManager Pm = getPackageManager();

    ApplicationInfo nameApp = Pm.getApplicationInfo(value2, 0);

    name.setSummary(Pm.getApplicationLabel(nameApp));

Value2是一個變量的名稱，該變量取自前一個Activity的包的名稱，並且此步驟運行良好，因為包的名稱已正確傳遞和恢復

Answer 1

嘗試這個..

    PackageManager packageManager=this.getPackageManager();
    List<ApplicationInfo applist=packageManager.getInstalledApplications(0);


    Iterator<ApplicationInfo> it=applist.iterator();
    while(it.hasNext()){
        ApplicationInfo pk=(ApplicationInfo)it.next();

        String appname = packageManager.getApplicationLabel(pk).toString();
        System.out.println("Application name : "+appname);
    }

或特定包名稱

final PackageManager pm = getApplicationContext().getPackageManager();
ApplicationInfo ai;
try {
    ai = pm.getApplicationInfo(PackageName, 0);
} catch (final NameNotFoundException e) {
    ai = null;
}
final String applicationName = (String) (ai != null ? pm.getApplicationLabel(ai) : "(unknown)");
System.out.println("Application name : "+applicationName);

Answer 2

嘗試使用此方法，用於包

Resources appR = ctx.getResources();
CharSequence txt = appR.getText(appR.getIdentifier("app_name",
"string", ctx.getPackageName()));

對於應用程序名稱，使用PackageManager#getApplicationInfo()