如何更改导航抽屉标题中的 TextView 文本？

我想要更改导航抽屉标题内的 TextView 文本，但是我得到了这个错误:

NullPointerException: 尝试调用虚方法‘ void 在 null 上的 android.widget. TextView.setText (java.lang. CharSequence)’ 对象引用

Activity _ main. xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">


<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">


<include
layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="wrap_content" />


<FrameLayout
android:id="@+id/frame_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />


</LinearLayout>


<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_main_drawer" />


</android.support.v4.widget.DrawerLayout>

Nav _ header _ main

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/nav_header_height"
android:background="@drawable/slide_nav_bar"
android:gravity="bottom"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:theme="@style/ThemeOverlay.AppCompat.Dark">


<ImageView
android:id="@+id/tvHeaderIcon"
android:layout_width="60dp"
android:layout_height="60dp"
android:paddingTop="@dimen/nav_header_vertical_spacing"
android:src="@android:drawable/sym_def_app_icon" />


<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/nav_header_vertical_spacing"
android:text="@string/app_name"
android:textAppearance="@style/TextAppearance.AppCompat.Body1" />


<TextView
android:id="@+id/tvHeaderName"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />


</LinearLayout>

MainActivity.java

TextView tvHeaderName;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


tvHeaderName= (TextView) findViewById(R.id.tvHeaderName);
tvHeaderName.setText("Saly");
}

我怎么能这么做？

99407 次浏览
小开

You should inflate your Header layout from NavigationView first...

navHeaderView= navigationView.inflateHeaderView(R.layout.nav_header_main);
tvHeaderName= (TextView) navHeaderView.findViewById(R.id.tvHeaderName);
tvHeaderName.setText("Saly");
小开
最佳答案

Use function getHeaderView on your navigationView:

NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
View headerView = navigationView.getHeaderView(0);
TextView navUsername = (TextView) headerView.findViewById(R.id.navUsername);
navUsername.setText("Your Text Here");
小开

You can also use this as of 23.1.1 design support library

View header = navigationView.getHeaderView(0)
TextView text = (TextView) header.findViewById(R.id.textView);

Reference: https://stackoverflow.com/a/33692431/2761923

小开

What worked for me? its this:- 

 View linearLayout=navigationView.inflateHeaderView(R.layout.nav_header_main);
TextView name =  linearLayout.findViewById(R.id.welcomenametext);

But remember to remove this from your xml file i.e from NavigationView :-app:headerLayout="@layout/nav_header_main"

Ok apart from this above answer..over months i now figured there's a better way of doing it if you are advanced enough in android development!!Just put frame layout there and load fragment in it inside which we have Recyclerview and header section. With Recyclerview You can setup the header as you like with textviews,image,and many more as you like. The recent application I am working on just did that.Dynamically passed data into Recyclerview from fragmentactivity with out icons and also put a relative layout(inside textviews and imageview) which acts as header on top of Recyclerview.

小开

Use this to get the navigation header

View hview = navigationView.getHeaderView(0);

then use the hview to get the different views of navigation header and do whatever you want

else using navHeaderView= navigationView.inflateHeaderView(R.layout.nav_header_main); this is creating a new header at index 1.

小开

Intially, we have to get the instance of navigation view by inflating the navigation view in a view varible, later you can get the textView instance to edit the textview

小开

  1. You need to get NavigationView id in your Activity like this

    NavigationView navigationView = (NavigationView) findViewById(R.id.navigationView );

  2. Now get HeaderView Layout using Navigationview id like this

    View headerView = navigationView.getHeaderView(0);

  3. Now you can get Any view id and perform action what you want example

    TextView navUsername = (TextView) headerView.findViewById(R.id.navUsername);
navUsername.setText("Your Text Here");
小开

This worked for me:

NavigationView navigationView = findViewById(R.id.nav_view);
View headerView = navigationView.getHeaderView(0);
TextView title = headerView.findViewById(R.id.nav_title);
TextView subTitle = headerView.findViewById(R.id.nav_sub_title);
小开

Here is the Kotlin version of the code, hope it helps someone out there. 

val navigationView : NavigationView  = findViewById(R.id.nav_view)
val headerView : View = navigationView.getHeaderView(0)
val navUsername : TextView = headerView.findViewById(R.id.txtUserName)
val navUserEmail : TextView = headerView.findViewById(R.id.txtEmail)


navUsername.text = username.toString()
navUserEmail.text = email.toString()
小开 
val navigationView = findViewById<View>(R.id.nav_view_home) as NavigationView
val headerView = navigationView.getHeaderView(0)
val tvUserName = headerView.findViewById<View>(R.id.tvUserName) as TextView
tvUserName.text=(Preference.getInstance("your text")
小开

I have same problem, but both given solutions didn't work for me

java.lang.IllegalStateException: Required view 'nav_header_username' with ID 2131296646 for field 'username' was not found. If this view is optional add '@Nullable' (fields) or '@Optional' (methods) annotation.

I have almost same code as posted above:

NavigationView navigationView = (NavigationView)findViewById(R.id.navigation_content);
View headerView = navigationView.inflateHeaderView(R.layout.nav_header);
TextView navUsername = (TextView) headerView.findViewById(R.id.nav_header_username);
navUsername.setText("Hello, "+mUserSession.getLoggedUserData().getmFirstName());

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