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Questions tagged [findviewbyid]

findViewById(int id) is a method of the View and Activity classes. This method will take a resource Id usually in the form of R.id.mView and will return to you a View object that is a reference to that View. Note that the returned object will nearly always need to be cast to the correct type of View before you can start interacting with it. If a View by the given ID does not exist within the current activity or parent View then you will receive null.

563 questions
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findViewById in Fragment

I am trying to create an ImageView in a Fragment which will refer to the ImageView element which I have created in the XML for the Fragment. However, the findViewById method only works if I extend an Activity class. Is there anyway of which I can…
simplified.
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How can I assign an ID to a view programmatically?

In an XML file, we can assign an ID to a view like android:id="@+id/something" and then call findViewById(), but when creating a view programmatically, how do I assign an ID? I think setId() is not the same as default assignment. setId() is…
DuyguK
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No need to cast the result of findViewById?

Recently I found that AndroidStudio reminds me to remove some class cast. I remember that in the old time, we have to cast the result of findViewById, but now it's not necessary. The result of findViewById is still View, so i want to know why we…
Eric Zhao
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Null pointer Exception - findViewById()

Can anyone help me to find out what can be the issue with this program. In the onCreate() method the findViewById() returns null for all ids and this causes a null pointer exception later. I can not figure out why the findViewById() can not find the…
user2629828
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using findviewbyid in a class that does NOT extend Activity in android

I have a class that is currently extending Activity and I have methods like findViewById, ArrayAdapter etc. I want to turn it into an independent class but all the above methods become undefined. What is the problem? Shouldn't importing the classes…
Namratha
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How to use view binding in Android

I have been using findViewById and then ButterKnife to bind views. Recently, I came across this article and am not quite sure how to use it. I tried doing it but it does not seem to work in Android Studio 3.4.2 val binding =…
siera
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Kotlin Android View Binding: findViewById vs Butterknife vs Kotlin Android Extension

I'm trying to figure out the best way to do Android View Binding in Kotlin. It seems like there are a few of options out there: findViewById val button: Button by lazy { findViewById
triad
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Can not resolve method 'findViewById(int)'

I'm having a trouble with findViewByid but I can't find where the problem is. Here's my FirstFragment class code: import android.app.Fragment; import android.os.Bundle; import android.support.annotation.Nullable; import…
Ferhat
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NoSuchFieldError on findViewById()

There's two android projects I want to merge, one is Main and the other is linked as Library. But I have some troubles on this line: Button modificarC; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); …
Mauricio Zárate
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Access Fragment View from Activity's onCreate

I am in the process of making my first app for Android, and I have a Fragment that gets added to my Activity in the Activity's onCreate() method. The problem I am facing is that I am unable to find any of the views contained within the Fragment from…
Dan
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Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference

When my SplashActivity opens the LoginActivity my app crashes. The following is my SplashActivity.java: package com.example.android.appName; import android.content.Intent; import android.os.Bundle; import…
user5404864
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findViewById within fragment

Is there any way to find a view by id within the scope of a fragment? I'm using a series of fragments to render a specialized list. The fragments are loaded from a layout, so their widgets all have the same ids. I suppose I can figure out a way to…
Peri Hartman
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Class cast exception to same class on Android

I'm having a strange problem with ClassCastException on Android. One class cannot be casted to the same class: java.lang.RuntimeException: Unable to start activity ComponentInfo: java.lang.ClassCastException: com.example.model.BadeWrapper cannot be…
rwojcik
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Android findViewById() in Custom View

I've written my custom View and i want to update some other views after interacting with my custom view. Main Layout:
Jilberta
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FindViewById where ID is dynamic string

I have a table of 40 squares and each has an ID. When I'm passing Bundle from another activity I need to extract Note, Color and ID from that bundle. And then the app will change/add text and change background of the square specified by extracted…
user1926837
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