findviewbyid

Cast result findViewById android method

由 喜你入骨 提交于 2019-11-27 14:33:01
Why do we always have to cast the value returned by the method findViewById(id) ? The method already returns a view, as I've seen in google reference : http://developer.android.com/reference/android/view/View.html#findViewById(int) Then is it possible to cast to another thing apart form a view ? For example, do this : ImageView image = (ImageView) findViewById(R.id.image) ? The method findViewById() returns an instance of the class that is actually used to define that view in your XML file. The method signature returns a View to make it generic and usable for all classes that inherit for View

findViewById within fragment

由 感情迁移 提交于 2019-11-27 11:36:44
问题 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 give each widget a custom id during (or right after) creation. However, it would be a lot nicer if I could somehow limit the findViewById to the scope of the fragment. 回答1: private View myFragmentView; @Override public View onCreateView

using findviewbyid in a class that does NOT extend Activity in android

由 对着背影说爱祢 提交于 2019-11-27 11:07:18
问题 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 be enough? For eg, I import android.view.View for findViewById but it still makes no difference. Please advise. 回答1: you should pass the instance of your Activity to your Second Class on the constructor like this : In your Activity Instanciate your

How do I “findViewById” with fragments?

由 我是研究僧i 提交于 2019-11-27 09:08:20
I recently moved my project to Android Studio from Eclipse. I am trying to get the email functionality working, however I receive errors by "findViewById". I also receive errors by "Toast.makeText". Could you please assist on both errors. The code in my class is as follows: package com.example.ishonours.witsbusapp; import android.app.Activity; import android.net.Uri; import android.os.Bundle; import android.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.content.Intent; import android.widget.Button; import android.widget

Android: findViewById returns Null even if is after setContentView

由 做~自己de王妃 提交于 2019-11-27 08:26:24
问题 Here's my code in LoginActivity: @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login); if (savedInstanceState == null) { getSupportFragmentManager().beginTransaction() .add(R.id.container, new PlaceholderFragment()).commit(); } loginButton = (Button)findViewById(R.id.loginButton); loginButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { onLoginButtonClicked(); } });

Class cast exception to same class on Android

由 帅比萌擦擦* 提交于 2019-11-27 01:50:43
问题 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 cast to com.example.model.BadgeWrapper java.lang.ClassCastException: com.example.events.widgets.TouchyWebView cannot be cast to com.example.events.widgets.TouchyWebView java.lang.ClassCastException: com.example.friends.widgets.FriendsTabView cannot

Access Fragment View from Activity's onCreate

由 落花浮王杯 提交于 2019-11-27 00:28:07
问题 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 the Activity 's onCreate() method. Other threads have suggested that this is because the Fragment has not yet been inflated, so findViewById() will return null for any views contained within the Fragment . Here is what I mean: Activity: @Override

findViewById() returns null for Views in a Dialog

由 随声附和 提交于 2019-11-26 22:58:50
The problem is, no matter where or how I call for this layout's components, they always return null. setView(inflater.inflate(R.layout.search_layout, null)) This works fine. It displays the layout inside the Dialog , yet, the children are always returned as null by findViewById(R.id.some_search_layout_children) . I've tried cleaning my project multiple times, tried to implement another class for my Dialog , called findViewById() as a member of my main Activity , inside the initSearch() method, and inside an anonymous implementation of OnClickListener for the Dialog , but all with the same

How do I “findViewById” with fragments?

由 冷暖自知 提交于 2019-11-26 17:47:33
问题 I recently moved my project to Android Studio from Eclipse. I am trying to get the email functionality working, however I receive errors by "findViewById". I also receive errors by "Toast.makeText". Could you please assist on both errors. The code in my class is as follows: package com.example.ishonours.witsbusapp; import android.app.Activity; import android.net.Uri; import android.os.Bundle; import android.app.Fragment; import android.view.LayoutInflater; import android.view.View; import

Cast result findViewById android method

由 六月ゝ 毕业季﹏ 提交于 2019-11-26 16:48:27
问题 Why do we always have to cast the value returned by the method findViewById(id) ? The method already returns a view, as I've seen in google reference : http://developer.android.com/reference/android/view/View.html#findViewById(int) Then is it possible to cast to another thing apart form a view ? For example, do this : ImageView image = (ImageView) findViewById(R.id.image) ? 回答1: The method findViewById() returns an instance of the class that is actually used to define that view in your XML
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