Question

布局

<?xml version="1.0" encoding="utf-8"?>

 <LinearLayout 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:layout_width="wrap_content"
android:layout_height="match_parent"
android:id="@+id/llist"
tools:context="com.android.parteek.contentprovider.Main2Activity">

<android.support.v7.widget.SearchView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/serch">
</android.support.v7.widget.SearchView>

<ListView
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.android.parteek.contentprovider.Main2Activity">

</ListView>

</LinearLayout>

代码

package com.android.parteek.contentprovider;

import android.content.ContentResolver;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.SearchView;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class Main2Activity extends AppCompatActivity implements AdapterView.OnItemLongClickListener, SearchView.OnQueryTextListener {
ListView l;
ArrayList<Bean> arrayList;
UserAdapterr userAdapterr;
ContentResolver contentResolver;
SearchView searchView;
Bean b,b1;
int pos;
void views(){
    l=(ListView)findViewById(R.id.list);
    searchView=(SearchView)findViewById(R.id.serch);

}
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    views();
    contentResolver=getContentResolver();
    retrieve();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.searchmenu,menu);
    searchView=(SearchView)menu.findItem(R.id.search).getActionView();
   searchView.setIconifiedByDefault(true);
   searchView.setOnQueryTextListener(this);
   searchView.setQueryHint("search.....");

    return super.onCreateOptionsMenu(menu);
}


@Override
public boolean onQueryTextSubmit(String query) {
    return false;
}

@Override
public boolean onQueryTextChange(String newText) {
    return false;
}
}

错误

 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.SearchView.setIconifiedByDefault(boolean)' on a null object reference
                                                                                         at com.android.parteek.contentprovider.Main2Activity.onCreateOptionsMenu(Main2Activity.java:147)

Answer 1

如果您想在操作栏中使用它，请将其从活动中删除。将其添加到searchmenu.xml。

您的错误与这些行相关，因此请修复您正在膨胀的xml文件

getMenuInflater().inflate(R.menu.searchmenu,menu);
searchView=(SearchView)menu.findItem(R.id.search).getActionView();
searchView.setIconifiedByDefault(true);

您可以有效删除此搜索视图

void views(){
    l=(ListView)findViewById(R.id.list);
    // searchView=(SearchView)findViewById(R.id.serch);

}

将SearchView放在ActionBar上

1 个答案: