NullPointerExcpetion on findViewById

NullPointerExcpetion on findViewById

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NullPointerExcpetion on findViewById
Tag : java , By : MK.
Date : November 24 2020, 09:00 AM

will help you selectLesson selectLesson = new selectLesson(); is not a proper way to instantiate an Activity in Android. Read more about it here: http://developer.android.com/training/basics/firstapp/starting-activity.html
BUT, in your case you might actually want to move the logic from selectLesson class into MainActivity and just call the nextlesson() method from there.

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Java arrays - Keep getting NullPointerExcpetion

Tag : java , By : Anthony Eden
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further You never instantiate your array enemy.
At some point, before you use enemy, you'll need something like: enemy = new Enemy[numEnemies];. You can do it in the declaration:
// use a constant for the number of enemies:
public static final int NUM_ENEMIES = 20; 
Enemy enemy[] = new Enemy[NUM_ENEMIES];

Fabric For Android Studio threw an unchaught NullPointerExcpetion

Tag : android , By : user105769
Date : March 29 2020, 07:55 AM
This might help you I'm using Fabric with both Android Studio and Eclipse, and the plugin was really an easy tool, From a couple of weeks the Plugin for Android Studio is not working any more, I have tried to install/uninstall several times with no success, this mainly happened after the plugin is moved into Repositories. Every time on the start up of Android Studio there is a floating message says , I have contacted Fabric support and that was their reply

NullPointerExcpetion when updating database

Tag : android , By : orneka
Date : March 29 2020, 07:55 AM
With these it helps so i have this app i'm trying to make that requires updating the database it's using, but it keeps giving me this error:
SQLiteDatabase db = this.getWritableDatabase();
    final String COLUMN_NAME = "Enyes";
    final String WHERE_CLAUSE = "_id = '" + id + "'";
    ContentValues values = new ContentValues();
    values.put(COLUNM_NAME, num);
    db.update(TABLE_NAME, values, WHERE_CLAUSE, null);

    Cusror cursor = db.rawQuery("SELECT " + COLUMN_NAME + " FROM " + TABLE_NAME + "WHERE _id ='" + id "'");

    Log.e(COLUMN_NAME, cursor.getString(0));

findViewById in RecyclerView ViewHolder throws NullPointerExcpetion

Tag : java , By : Vinicios
Date : March 29 2020, 07:55 AM
hop of those help? You need to initialize views in your ItemViewHolder before using them. Right now frag_name.findViewById(R.id.recycler_name) will throw NullPointerException cause your trying to use wrong view to findViewById().
Use this code:
public ItemViewHolder(@NonNull View itemView) {
        frag_name = itemView.findViewById(R.id.recycler_name);
        frag_price = itemView.findViewById(R.id.recycler_price);
        frag_date = itemView.findViewById(R.id.recycler_date);

Is it equivalent to call getActivity().findViewById instead of <any_inflated_layout>.findViewById in a fragment?

Tag : android , By : Juice
Date : March 29 2020, 07:55 AM
I wish this helpful for you In my fragment's onCreateView method, I used to store the inflated layout in a variable and then pass the latter to my other functions that called findViewById on this inflated View. ,
In terms of RAM or CPU consumption
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