您好我试图找到每个解决方案,但没有解决方案正在解决我的问题。我在android中制作导航画,但是这部分的头部显示零点异常我怎么能解决这个问题
活动代码是
navigationView = findViewById(R.id.nav_view);
headerView = getLayoutInflater().from(this).inflate(R.layout.nav_header_main, null);
navigationView.addHeaderView(headerView);
profile = headerView.findViewById(R.id.img_profile);
name = headerView.findViewById(R.id.name);
companyname = headerView.findViewById(R.id.companyname);
这是Actitvty的xml,我宣布了android的导航程序
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
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.design.widget.NavigationView>
这是标题xml
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:orientation="horizontal"
android:padding="@dimen/_16sdp">
<ImageView
android:id="@+id/img_profile"
android:layout_width="@dimen/_90sdp"
android:layout_height="@dimen/_90sdp"
android:layout_marginRight="@dimen/_10sdp"
android:padding="@dimen/_2sdp"
android:paddingTop="@dimen/_16sdp"
android:src="@drawable/companylogo" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="@dimen/_10sdp"
android:layout_marginTop="@dimen/_12sdp"
android:orientation="vertical">
<TextView
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="@dimen/_1sdp"
android:text="Welcome!"
android:textAppearance="@style/TextAppearance.AppCompat.Body1"
android:textColor="@color/second_color"
android:textStyle="bold" />
<TextView
android:id="@+id/companyname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="@dimen/_10sdp"
android:text="Mr Salesman"
android:textAppearance="@style/TextAppearance.AppCompat.Body1"
android:textColor="@color/second_color"
android:textStyle="bold" />
<TextView
android:id="@+id/website"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="GLINT LOGIC"
android:textColor="@color/second_color"
android:textStyle="bold" />
</LinearLayout>
这是导致XML的错误,我的应用程序被Android
杀死Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.support.design.widget.NavigationView.inflateHeaderView(int)' on a null object reference
at com.example.aka.gism.all_activity.MainActivity.onCreate(MainActivity.java:85)
at android.app.Activity.performCreate(Activity.java:6964)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2752)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2870)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1573)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6605)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:999)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:889)
答案 0 :(得分:0)
您不需要在导航视图中夸大布局标题,而不是此
headerView = getLayoutInflater().from(this).inflate(R.layout.nav_header_main, null);
navigationView.addHeaderView(headerView);
使用
headerView = navigationView.getHeaderView(0) // 0 is first header
profile = headerView.findViewById(R.id.imageProfile);
答案 1 :(得分:0)
试试这个,
navigationView = findViewById(R.id.nav_view);
View header=navigationView.getHeaderView(0);
profile = header.findViewById(R.id.img_profile);
name = header.findViewById(R.id.name);
companyname = header.findViewById(R.id.companyname);