我正在尝试在navigationView edittext中添加addtextchangedlistener事件。
我想添加它，所以每当我在文本框中输入字符时，它会自动捕获文本，然后使用提供的文本过滤我的菜单。
当我运行应用程序时会发生什么，它会抛出一个空指针异常 addTextChangedListener。如何修复此问题以允许它检测输入并从那里控制它？
这是我的xml和类文件：
nav_header_home.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="@dimen/nav_header_height"
android:background="#e3e4e5"
android:theme="@style/ThemeOverlay.AppCompat.Dark" android:orientation="vertical" >
<EditText
android:layout_width="match_parent"
android:layout_height="@dimen/search_bar_layout_height"
android:id="@+id/editTextSearchBar"
android:background="@drawable/rounded_edittext"
android:hint="Search"
android:textColorHint="@color/colorSearchBarHint"
android:textAlignment="center"
android:drawableLeft="@drawable/ic_menu_search"
android:textColor="@color/colorProfileName"
/>
</LinearLayout>
<LinearLayout
activity_home.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">
<include layout="@layout/app_bar_home" android:layout_width="match_parent"
android:layout_height="match_parent" />
<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_home" app:menu="@menu/activity_home_drawer" />
</android.support.v4.widget.DrawerLayout>
我的HomeActivity类：
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;
import android.widget.ListView;
import com.app.test.R;
public class HomeActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
int mProfileMenuCtr = 0;
String [] mValues = {"Inbox","News","My Profile"};
EditText mSearchBar;
String mTempText;
int [] mTempCtr;
int mTempCtr2;
MenuItem mItem;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mSearchBar = (EditText)findViewById(R.id.editTextSearchBar);
mSearchBar.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
mSearchBar.setError(null);
}
@Override
public void afterTextChanged(Editable s) {
mTempText = mSearchBar.toString();
mTempCtr2 = 0;
for(int o = 0;o <mValues.length;o++){
boolean containerContainsContent = mValues[o].toLowerCase().contains(mTempText.toLowerCase());
if(containerContainsContent)
{
mTempCtr2++;
mTempCtr [mTempCtr2] = o;
}
}
invalidateOptionsMenu();
}
});
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
}
@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_home_drawer, menu);
return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu){
getMenuInflater().inflate(R.menu.activity_home_drawer, menu);
hideMenuItems(menu, false);
return super.onPrepareOptionsMenu(menu);
}
private void hideMenuItems(Menu menu, boolean visible)
{
for(int i = 0; i < menu.size(); i++){
menu.getItem(i).setVisible(visible);
}
for(int ii = 0; ii < mTempCtr.length;ii++){
menu.getItem(ii).setVisible(true);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_inbox) {
} else if (id == R.id.nav_news) {
} else if (id == R.id.nav_my_profile) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
答案 0 :(得分：1)
回答为时已晚，但这是我的回答
查找导航标题，然后找到EditText
View header = navigationView.getHeaderView(0);
mSearchBar = (EditText) header.findViewById(R.id. editTextSearchBar);
然后在EditText