我有两个抽屉导航，一个带有 ListView，第二个带有布局。第一个 Navigationdrawer 工作正常，但第二个无法通过单击按钮打开它。
这是 MainActivity xml 代码:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:layout_gravity="right"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/orange"
android:id="@+id/toolbar"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:navigationIcon="@drawable/arrow"
app:title="MyGames"
>
<Button
android:id="@+id/rigthMenu"
android:background="@drawable/compose"
android:layout_width="36dp"
android:layout_height="36dp"
android:layout_marginRight="5dp"
android:layout_gravity="right" />
</android.support.v7.widget.Toolbar>
</RelativeLayout>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollIndicators="bottom">
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</FrameLayout>
<ListView
android:id="@+id/left_drawer"
android:layout_width="300dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="2dp"
android:background="#ffffff"
android:scrollbars="vertical"/>
<include
android:id="@+id/layRigth"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="end"
layout="@layout/rigth_menu" />
</android.support.v4.widget.DrawerLayout>
这是 rigthMenu 布局 xml 代码:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:gravity="left">
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New CheckBox"
android:id="@+id/checkBox2"
android:layout_gravity="center_horizontal" />
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New CheckBox"
android:id="@+id/checkBox"
android:layout_gravity="center_horizontal" />
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New CheckBox"
android:id="@+id/checkBox4"
android:layout_gravity="center" />
这是 MainActivity OnCreate 代码:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// mDrawerLayout2 = (DrawerLayout)findViewById(R.id.layRigth);
android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onIcon = !onIcon;
if (onIcon == true) {
mDrawerLayout.openDrawer(mDrawerList);
} else {
mDrawerLayout.closeDrawer(mDrawerList);
}
}
});
Button rigthMenu = (Button)findViewById(R.id.rigthMenu);
rigthMenu.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final LayoutInflater factory = getLayoutInflater();
final View text = factory.inflate(R.layout.rigth_menu, null);
mDrawerLayout2 = (DrawerLayout)text.findViewById(R.id.layRigth);
mDrawerLayout2.openDrawer(mDrawerLayout2);
}
});
Drawable x = toolbar.getNavigationIcon();
getDefaultSettings("Image", this);
// mNavigationView = (NavigationView) findViewById(R.id.shitstuff) ;
mFragmentManager = getSupportFragmentManager();
mFragmentTransaction = mFragmentManager.beginTransaction();
mFragmentTransaction.replace(R.id.content_frame,new TabFragment()).commit();
// Initializing
dataList = new ArrayList<DrawerItem>();
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
// Add Drawer Item to dataList
dataList.add(new DrawerItem(R.mipmap.ps4miniatura, GREEN, 1));
dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));
dataList.add(new DrawerItem(0, " ", 2));
adapter = new CustomDrawerAdapter(this, R.layout.custom_drawer_item, adapter,
dataList);
// addItem.giveAdapter(adapter);
mDrawerList.setAdapter(adapter);
mDrawerList.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
if (savedInstanceState == null) {
SelectItem(1);
}
}
Logcat 错误:
12-08 08:40:52.936 15587-15587/com.tutecentral.navigationdrawer E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.tutecentral.navigationdrawer, PID: 15587
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.widget.DrawerLayout.openDrawer(android.view.View)' on a null object reference
at com.tutecentral.navigationdrawer.MainActivity$2.onClick(MainActivity.java:75)
at android.view.View.performClick(View.java:4820)
at android.view.View$PerformClick.run(View.java:20157)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5578)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:955)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:750)
我有一个 nullPointException。如何获取布局 rigthMenu 的 View ？
最佳答案
rigthMenu 的 OnClickListener 中存在一些错误。首先，没有必要在那里膨胀 rigth_menu 布局。您已将其包含在主布局中，因此它已经膨胀。此外，rigth_menu 不包含任何 ID 为 layRigth 的 View，因此 text.findViewById(R.id.layRigth) 返回 null，并导致 NullPointerException。而且，您已经获得了对 DrawerLayout - mDrawerLayout 的引用 - 因此您不需要再次找到它。
rigthMenu.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(mDrawerLayout.isDrawerOpen(GravityCompat.END)) {
mDrawerLayout.closeDrawer(GravityCompat.END);
}
else {
mDrawerLayout.openDrawer(GravityCompat.END);
}
}
});
关于java - 单击事件打开带布局的抽屉导航，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34150332/