java - Android Studio searchiew 图标没有出现

问题描述

我对android studio很陌生。我试图为我当前的项目提出一个搜索视图。

我希望搜索图标保留在应用程序的顶部。但是，当我运行模拟器时，它不会出现。

我在网上搜索了解决方案，将 ListView Height 更改为离散 dp 而不是“match_parent”，将菜单项 app:ShowAsAction 更改为“ifRoom|collapseActionView”和“always”。它不会改变任何东西。我对此感到非常困惑，希望有人能帮助我解决这个问题。

这是我的 mainactivity.xml 代码

    <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@android:color/black"
        android:dividerHeight="2dp"
        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="0dp"
        tools:listitem="@android:layout/simple_list_item_1" />


</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity java 文件

package com.example.test;

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.view.MenuItemCompat;

import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    //initialise variable
    ListView listView;
    ArrayList<String> carparkList = new ArrayList<>();
    ArrayAdapter<String> adapter;

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

        //Assign variable
        listView = findViewById(R.id.list_view);

        //Add item in array list
        for (int i = 1; i <20; i++) {
            carparkList.add("Carpark" + i);
        }

        //Initialise adapter
        adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1,carparkList);

        //Set adapter on list view
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //Display click item position in toast
                Toast.makeText(getApplicationContext(), adapter.getItem(position), Toast.LENGTH_SHORT).show();
            }
        });
    }

    public boolean onCreateOptionMenu(Menu menu) {
        //Initialise menu inflator
        MenuInflater menuInflater = getMenuInflater();
        //Inflate menu
        menuInflater.inflate(R.menu.menu_search, menu);
        //initialise menu item
        MenuItem menuItem = menu.findItem(R.id.search_view);
        //Initialise searchview
        SearchView searchView = (SearchView) menuItem.getActionView();

        searchView.setQueryHint("Type your destination");

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                //filter array list
                adapter.getFilter().filter(newText);
                return false;
            }
        });
        return super.onCreateOptionsMenu(menu);
    }
}

和 menu_search.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/search_view"
        android:title="Search"
        app:showAsAction="ifRoom|collapseActionView"
        android:icon="@drawable/ic_search"
        app:actionViewClass="androidx.appcompat.widget.SearchView"/>
</menu>

标签： javaandroid

java - Android Studio searchiew 图标没有出现

问题描述

解决方案

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