寫在前面

由于本人初學(xué)階段，寫這篇博客是總結(jié)所學(xué)的知識點阔拳，為后面的進階打好基礎(chǔ)

有任何關(guān)于代碼和表述問題，歡迎評論區(qū)指出

樓主近期在學(xué)習(xí)關(guān)于安卓中Fragment和ListView中的知識宾濒，按照老師的要求模仿一下QQ界面 要求功能

• 有登錄界面
  • 密碼不對提示密碼不對
  • 賬號密碼任一為空提示用戶不能為空
  • 登錄成功提示登錄成功
  • 可以實現(xiàn)賬號密碼記住功能
• 有三個界面可以點擊底部按鈕實現(xiàn)頁面的切換
  • 實現(xiàn)按鈕選中狀態(tài)和未選中狀態(tài)不一樣
  • 聯(lián)系人界面
  • 信息界面
  • 狀態(tài)界面
• 發(fā)送信息功能
  • 點擊信息界面中的任意消息可以進入發(fā)消息界面
  • 可以實現(xiàn)點擊發(fā)送按鈕將所輸入的文字顯示在屏幕中

提示：本人用的IDE開發(fā)環(huán)境是Android Studio API是30

目錄結(jié)構(gòu)一覽

2MmRG6.png

res中的文件

2MmfxO.png

1. 登錄界面

• 登錄界面的布局文件

activity_main.xml

所用圖標(biāo)都可以在阿里巴巴圖標(biāo)網(wǎng)找到iconfont-阿里巴巴矢量圖標(biāo)庫

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:orientation="vertical"
        tools:ignore="UselessParent">
        <TextView
            android:drawableLeft="@drawable/qq"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dp"
            android:layout_marginLeft="120dp"
            android:gravity="center"
            android:text="QQ"
            android:textColor="#000000"
            android:textSize="35sp"
            app:drawableStartCompat="@drawable/qq"
            android:drawableStart="@drawable/qq"
            tools:ignore="UseCompatTextViewDrawableXml"
            android:layout_marginStart="120dp">
        </TextView>
        <EditText
            android:id="@+id/userNameEditText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="100dp"
            android:hint="請輸入用戶名/賬號/手機號"
            android:inputType="text"
            android:padding="5dp">
        </EditText>
        <EditText
            android:id="@+id/passwordEditText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:hint="請輸入密碼"
            android:inputType="textPassword"
            android:padding="5dp">
        </EditText>
        <ImageButton
            android:id="@+id/loginButton"
            android:layout_marginTop="60dp"
            android:layout_gravity="center"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:src="@drawable/login"
            android:background="#fff">
        </ImageButton>
    </LinearLayout>

</RelativeLayout>

所對應(yīng)的MainActivity

• 其中的判斷通過if語句判斷用戶是否輸入和輸入正確
• 提示 通過Toast的方式提示

package com.czie.qq;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private Context context;
    private EditText userNameEditText, passwordEditText;
    private ImageButton loginButton;
    private ShareHelper shareHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context=this;
        shareHelper=new ShareHelper(context);
        initview();
    }

    private void initview() {
        userNameEditText = findViewById(R.id.userNameEditText);
        passwordEditText = findViewById(R.id.passwordEditText);
        loginButton = findViewById(R.id.loginButton);
        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //進行登錄頁面的處理
                String username = userNameEditText.getText().toString();
                String password = passwordEditText.getText().toString();
                if (username.length() > 0) {
                    if (username.equals("zk")) {
                        if (password.length() > 0) {
                            if (password.equals("123")) {
                                // 對賬號和密碼進行保存
                                shareHelper.save("username",username);
                                shareHelper.save("password",password);
                                startActivity(new Intent(MainActivity.this, HomeActivity.class));
                                Toast.makeText(MainActivity.this, "登錄成功", Toast.LENGTH_SHORT).show();
                            } else {
                                Toast.makeText(MainActivity.this, "密碼不正確", Toast.LENGTH_LONG).show();
                            }
                        } else {
                            Toast.makeText(MainActivity.this,"請?zhí)顚懨艽a",Toast.LENGTH_LONG).show();
                        }
                    } else {
                        Toast.makeText(MainActivity.this,"用戶名不正確",Toast.LENGTH_LONG).show();
                    }
                } else {
                    Toast.makeText(MainActivity.this,"請?zhí)顚懹脩裘?,Toast.LENGTH_LONG).show();
                }
            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();
        userNameEditText.setText(shareHelper.read("username"));
        passwordEditText.setText(shareHelper.read("password"));

    }
}

2. 記住密碼功能

• 實現(xiàn)第一次登錄成功后欣簇，再次登錄會記住賬號和密碼的功能

這個功能我們用SharedPreferences

簡單了解下什么是SharedPreferences

• SharedPreferences是Android平臺上一個輕量級的存儲輔助類，用來保存應(yīng)用的一些常用配置翘狱，它提供了string秘案，set，int潦匈，long阱高，float，boolean六種數(shù)據(jù)類型茬缩。最終數(shù)據(jù)是以xml形式進行存儲赤惊。在應(yīng)用中通常做一些簡單數(shù)據(jù)的持久化緩存。

package com.czie.qq;

import android.content.Context;
import android.content.SharedPreferences;

public class ShareHelper {
    //兩個功能 保存凰锡，讀取
    Context context;

    public ShareHelper() {
    }

    public ShareHelper(Context context) {
        this.context = context;
    }

    //保存
    public void save(String key, String value) {
        SharedPreferences sharedPreferences = context.getSharedPreferences("iot1921", Context.MODE_PRIVATE);
        //創(chuàng)建一個輸入值
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(key, value);
        editor.commit();
    }

    //讀取數(shù)據(jù)
    public String read(String key) {
        SharedPreferences sharedPreferences = context.getSharedPreferences("iot1921", Context.MODE_PRIVATE);
        return sharedPreferences.getString(key, "");
    }
}

注意事項：

• 輸入值記得提交未舟，editor.commit();
• 在MainACtivity中記得在OnStart方法中使用ShareHelper.read傳入需要記住的值！

預(yù)覽一下成果掂为！

1

3. Fragment界面跳轉(zhuǎn)

這里有三個Fragment裕膀，所對應(yīng)需要三個fragment布局界面

• 首先要創(chuàng)建3個按鈕的切換xml

message.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/message_on" android:state_selected="true"/>
    <item android:drawable="@drawable/message_off" android:state_selected="false"/>
</selector>

people.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/people_on" android:state_selected="true"/>
    <item android:drawable="@drawable/people_off" android:state_selected="false"/>
</selector>

statue.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/statue_on" android:state_selected="true"/>
    <item android:drawable="@drawable/statue_off" android:state_selected="false"/>
</selector>

然后在布局界面中使用

activity_home.xml

這個界面的布局可以隨意發(fā)揮，本人做的比較簡單勇哗，見諒

• 3個ImageView和1個FrameLayout
• ImageView分別綁定點擊事件

<?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="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <ImageView
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:src="@drawable/basketball">
        </ImageView>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Upcoming">
        </TextView>
        
        <TextView
            android:layout_width="50dp"
            android:layout_marginLeft="250dp"
            android:layout_height="match_parent"
            android:text="+  -"
            android:textSize="25sp">
        </TextView>
    </LinearLayout>

    <FrameLayout
        android:layout_marginTop="10dp"
        android:id="@+id/frameLayout"
        android:layout_width="match_parent"
        android:layout_height="550dp">
    </FrameLayout>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:orientation="horizontal">
    <ImageView
        android:id="@+id/messageImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="60dp"
        android:background="@drawable/message"
        android:layout_weight="1"
        android:layout_marginStart="0dp">
    </ImageView>

    <ImageView
        android:id="@+id/peopleImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="150dp"
        android:background="@drawable/people"
        android:layout_weight="1"
        android:layout_marginStart="150dp"
        tools:ignore="ContentDescription">
    </ImageView>

        <ImageView
            android:id="@+id/statueImageView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="170dp"
            android:background="@drawable/statue"
            android:layout_weight="1"
            android:layout_marginStart="170dp"
            tools:ignore="ContentDescription">
        </ImageView>
    </LinearLayout>
</LinearLayout>

3.1 Fragement的界面編寫

item_listview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/backgrounds">

    <ListView
        android:id="@+id/messagelistView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ListView>

</LinearLayout>

fragment_message.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/backgrounds">

    <ListView
        android:id="@+id/messagelistView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ListView>

</LinearLayout>

fragment_people.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:textColor="#000000"
        android:text="這是聯(lián)系人頁面"
        tools:ignore="MissingConstraints">
    </TextView>

</LinearLayout>

fragment_statue.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:textColor="#000000"
        android:text="這是動態(tài)頁面"
        tools:ignore="MissingConstraints">
    </TextView>

</LinearLayout>

Fragment布局寫完就是重點如何在FrameLayout中加載

我們還需要創(chuàng)建布局所對應(yīng)的Fragment

每個Fragment要指定加載的布局和調(diào)用的方法

onCreateView()：每次創(chuàng)建昼扛、繪制該Fragment的View組件時回調(diào)該方法，F(xiàn)ragment將會顯示該方法返回的View組件欲诺。
onActivityCreated()：當(dāng)Fragment所在的Activity被啟動完成后回調(diào)該方法抄谐。

在這個文件中需要實現(xiàn)

• 點擊進入聊天界面
• 可以發(fā)送消息顯示在屏幕上

我們通過List集合中存放Map

Map中所存放的Key就是所創(chuàng)建的Names數(shù)組渺鹦，Value就是Images數(shù)組

通過創(chuàng)建SimpleAdapter對象來加載fragment_message

講下這三行關(guān)鍵的代碼

//加載在哪個布局界面
messagelistView= getActivity().findViewById(R.id.messagelistView);
//適配器中的參數(shù)
/**
context 上下文
dataList 集合中存放的值
R.layout.item_listview 加載的布局界面
new String[]{"Name","Image"} String數(shù)組 
new int[]{R.id.NameTextView,R.id.ImageView} int數(shù)組 獲取id
*/
        simpleAdapter=new SimpleAdapter(context,dataList,R.layout.item_listview,
                new String[]{"Name","Image"},
                new int[]{R.id.NameTextView,R.id.ImageView});
//加載適配器
        messagelistView.setAdapter(simpleAdapter);

一個獲取數(shù)據(jù)的方法getData()

 //list獲取數(shù)據(jù)
    public void getData(){
        //遍歷數(shù)組中的數(shù)據(jù) 添加到list中
        for (int i = 0; i < Names.length; i++) {
            //新建map 存放數(shù)組中的數(shù)據(jù) 最后存放在list中
            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("Name",Names[i]);
            map.put("Image",Images[i]);
            dataList.add(map);
        }
    }

MessageFragment

package com.czie.qq;

import android.app.Fragment;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MessageFragment extends Fragment {


    private Context context;
    private ListView messagelistView;


    List<Map<String,Object>> dataList=new ArrayList<Map<String,Object>>();
    String [] Names={"一號","二號","三號","四號","五號","六號","七號"};
    int [] Images={R.mipmap.kaochang,R.mipmap.kaojitui,R.mipmap.kaojichi,R.mipmap.kaoqiezi,R.mipmap.kaolajiao,R.mipmap.kaojinzhengu ,R.mipmap.kaonanguabing};

    //創(chuàng)建SimpleAdapter對象
    private SimpleAdapter simpleAdapter;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_message,container,false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        context=getActivity();
        initView();
    }
    private void initView() {
        messagelistView= getActivity().findViewById(R.id.messagelistView);
        getData();
        simpleAdapter=new SimpleAdapter(context,dataList,R.layout.item_listview,
                new String[]{"Name","Image"},
                new int[]{R.id.NameTextView,R.id.ImageView});
        messagelistView.setAdapter(simpleAdapter);
        //listView的項點擊監(jiān)聽事件
        messagelistView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                //獲取當(dāng)前項的數(shù)據(jù)
                String name=dataList.get(i).get("Name").toString();
                Intent intent=new Intent(getActivity(),TalkActivity.class);
                startActivity(new Intent(getActivity(), TalkActivity.class));
                intent.putExtra("name",name);
                Toast.makeText(context,"當(dāng)前點擊的選項名稱是"+name,Toast.LENGTH_SHORT).show();
            }
        });
    }

    //list獲取數(shù)據(jù)
    public void getData(){
        //遍歷數(shù)組中的數(shù)據(jù) 添加到list中
        for (int i = 0; i < Names.length; i++) {
            //新建map 存放數(shù)組中的數(shù)據(jù) 最后存放在list中
            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("Name",Names[i]);
            map.put("Image",Images[i]);
            dataList.add(map);
        }
    }
}

PeopleFragment

package com.czie.qq;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.Nullable;

public class PeopleFragment extends Fragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_people,container,false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }
}

StatueFragment

package com.czie.qq;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.Nullable;

public class StatueFragment extends Fragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_statue,container,false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }
}

最后在HomeActivity中使用

了解什么是FragmentTransaction

使用Fragment時，可以通過用戶交互來執(zhí)行一些動作蛹含，比如增加毅厚、移除、替換等浦箱。

所有這些改變構(gòu)成一個集合吸耿，這個集合被叫做一個transaction

HomeActivity

• 監(jiān)聽ImgaeView的點擊事件
• 初始化ImageView的選中狀態(tài)為false 通過方法傳入?yún)?shù)從而判斷哪個ImageView被點擊 將被點擊的狀態(tài)設(shè)為false
• showFragment(Fragment fragment)中通過隱藏Fragment，點擊ImageView時再判斷顯示哪個Fragment

package com.czie.qq;

import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

@SuppressWarnings({"all"})
public class HomeActivity extends Activity implements View.OnClickListener {
    private ImageView messageImageView, peopleImageView, statueImageView;
    private MessageFragment messageFragment;
    private PeopleFragment peopleFragment;
    private StatueFragment statueFragment;
    private final FragmentManager fragmentManager = getFragmentManager();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        initView();
        initFragment();
        showFragment(statueFragment);
    }

    private void initView() {
        messageImageView = findViewById(R.id.messageImageView);
        peopleImageView = findViewById(R.id.peopleImageView);
        statueImageView = findViewById(R.id.statueImageView);
        messageImageView.setOnClickListener(this);
        peopleImageView.setOnClickListener(this);
        statueImageView.setOnClickListener(this);
    }

    private void initFragment() {
        messageFragment = new MessageFragment();
        peopleFragment = new PeopleFragment();
        statueFragment = new StatueFragment();

        //展示
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.frameLayout, messageFragment);
        transaction.add(R.id.frameLayout, peopleFragment);
        transaction.add(R.id.frameLayout, statueFragment);
        transaction.commit();
    }


    @Override
    public void onClick(View view) {
        switch (view.getId()) {

            case R.id.messageImageView:
                init(messageImageView);
                showFragment(messageFragment);
                break;
            case R.id.peopleImageView:
                init(peopleImageView);
                showFragment(peopleFragment);
                //startActivity(new Intent(HomeActivity.this, ListViewActivity.class));
                break;
            case R.id.statueImageView:
                init(statueImageView);
                showFragment(statueFragment);
                break;
            default:
                break;

        }
    }

    public void init(ImageView imageView) {
        messageImageView.setSelected(false);
        peopleImageView.setSelected(false);
        statueImageView.setSelected(false);
        imageView.setSelected(true);
    }

    //展示指定的Fragment
    //定義當(dāng)前頁面
    private Fragment curFragment = new Fragment();

    public void showFragment(Fragment fragment) {
        //如果當(dāng)前的fragment與傳入的fragment是同一個憎茂，呢么將返回
        if (curFragment.equals(fragment)) {
            return;
        }
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.hide(messageFragment);
        transaction.hide(peopleFragment);
        transaction.hide(statueFragment);
        transaction.show(fragment);
        transaction.commit();
    }
}

注意事項

• 記得 transaction要commit

預(yù)覽一下成果!

2

4. 聊天界面

item_talking.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:padding="10dp"
    android:gravity="right">

    <TextView
        android:id="@+id/talkTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="300dp"
        android:text="烤腸"
        android:textSize="25sp"
        android:textColor="#000000"
        android:background="#cef"
        android:layout_marginStart="300dp">
    </TextView>

    <ImageView
        android:id="@+id/ImageView"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:background="@mipmap/kaochang">
    </ImageView>
</LinearLayout>

activity_talk.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textColor="#000000"
            android:text="康小莊"
            android:id="@+id/NameTextView"
            android:background="#44cef6">
        </TextView>
    <ListView
        android:id="@+id/listView2"
        android:layout_width="match_parent"
        android:layout_height="600dp"
        android:layout_weight="1"
        />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal"
            android:layout_gravity="bottom"
            >
            <EditText
                android:id="@+id/inputEditText"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1">
            </EditText>

            <Button
                android:id="@+id/sendButton"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="3"
                android:text="發(fā)送">
            </Button>
        </LinearLayout>
    </LinearLayout>
</RelativeLayout>

TalkActivity

• 通過Handler來實現(xiàn)消息發(fā)出去之后 對話框置為null
• 通過simpleAdapter實現(xiàn)加載到哪個布局界面的id

package com.czie.qq;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class TalkActivity extends Activity implements View.OnClickListener {
    private EditText inputEditText;
    private SimpleAdapter simpleAdapter;
    List<Map<String,String>> list=new ArrayList<Map<String,String>>();

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_talk);
        Context context = this;
        initView();
        TextView nameTextView = findViewById(R.id.NameTextView);
        Intent intent=getIntent();
        String name=intent.getStringExtra("name");
        nameTextView.setText(name);
    }

    private void initView() {
        inputEditText=findViewById(R.id.inputEditText);
        Button sendButton = findViewById(R.id.sendButton);
        ListView listView2 = findViewById(R.id.listView2);
        listView2.setDivider(null);
        simpleAdapter=new SimpleAdapter(this,list,R.layout.item_talking,new String[]{"message"},new int[]{R.id.talkTextView});
        listView2.setAdapter(simpleAdapter);
        sendButton.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {
        sendMessage();
        handler.sendEmptyMessage(0);
    }

    public void sendMessage(){
        String message=inputEditText.getText().toString();
        if (message.length()>0){
            HashMap<String, String> map = new HashMap<>();
            map.put("message",message);
            list.add(map);
            inputEditText.setText("");
        }
    }

    Handler handler=new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            simpleAdapter.notifyDataSetChanged();
        }
    };
}

3

總結(jié)：

• 學(xué)會了簡單的頁面跳轉(zhuǎn)功能珍语，提高思考的能力，學(xué)會如何用較少代碼實現(xiàn)功能
• 還有許多不足仍需努力

寫在最后：

• 有任何錯誤歡迎評論區(qū)指出竖幔，及時改正板乙！