【Android】【移动应用开发】APP案列

1. 通讯录功能实现

⚪页面布局代码如下：
activity_main.xml(主界面布局代码)

<?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="vertical">
<!--    打电话-->
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="35dp"
        android:background="#000">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="通讯录"
            android:textColor="#fff"
            android:textSize="20sp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tvadd"
            android:layout_alignParentRight="true"
            android:layout_marginRight="20dp"
            android:layout_marginTop="6dp"
            android:text="添加"
            android:textColor="#fff"
            android:textSize="18sp"/>

    </RelativeLayout>

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:dividerHeight="2dp"
        android:id="@+id/lv"/>

</LinearLayout>

activity_add_layout.xml(添加联系人界面布局代码)

<?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="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="35dp"
        android:background="#000">

        <ImageView
            android:layout_width="30dp"
            android:layout_height="25dp"
            android:layout_marginTop="5dp"
            android:id="@+id/imgreturn"
            android:layout_marginLeft="10dp"
            android:src="@mipmap/row_left"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_toRightOf="@+id/imgreturn"
            android:text="返回"
            android:textSize="20sp"
            android:textColor="#fff"/>
    </RelativeLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:orientation="vertical">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/edtName"
            android:hint="请输入姓名"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/edtTel"
            android:hint="请输入电话号码"/>
    </LinearLayout>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="120dp"
        android:layout_margin="10dp">

        <ImageView
            android:layout_width="40dp"
            android:layout_height="120dp"
            android:src="@mipmap/row_left"
            android:id="@+id/imgleft"/>

        <ImageView
            android:layout_width="120dp"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:id="@+id/img"
            android:src="@mipmap/liubei"/>

        <ImageView
            android:layout_width="40dp"
            android:layout_height="120dp"
            android:src="@mipmap/row_right"
            android:layout_alignParentRight="true"
            android:id="@+id/imgright"/>
    </RelativeLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal">

        <Button
            android:layout_width="80dp"
            android:layout_height="wrap_content"
            android:id="@+id/btnreset"
            android:text="重置"
            android:textSize="20sp"/>
        <Button
            android:layout_width="80dp"
            android:layout_height="wrap_content"
            android:id="@+id/btnok"
            android:text="添加"
            android:textSize="20sp"/>
    </LinearLayout>
</LinearLayout>

item.xml(模板布局代码)

<?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">

        <ImageView
            android:layout_width="60dp"
            android:layout_height="80dp"
            android:id="@+id/lxrimg"
            android:src="@mipmap/liubei"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/lxrname"
            android:layout_marginLeft="15dp"
            android:layout_marginTop="10dp"
            android:text="刘备"
            android:textSize="20sp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/lxrtel"
            android:layout_marginLeft="15dp"
            android:layout_marginTop="10dp"
            android:text="12345678"
            android:textSize="20sp"/>
    </LinearLayout>
</LinearLayout>

⚪Java代码如下：
Main_Activity.java(主界面功能实现代码)

package com.example.ceshi;


import androidx.appcompat.app.AppCompatActivity;
import androidx.collection.ArraySet;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.HashMap;

public class MainActivity extends AppCompatActivity {
   
    private ListView lv;
    private TextView add;
    private SimpleAdapter adapter = null;
    private ArrayList<Person> persons = new ArrayList<Person>();

    private boolean flag = false;
    private ArrayList<HashMap<String, Object>> lxrList = new ArrayList<HashMap<String, Object>>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
		
        Intent intent = this.getIntent();
        // 从add_layout的intent附加信息中取出添加的联系人信息
        persons = (ArrayList<Person>) intent.getSerializableExtra("persons");
        //标记已经通过add_layout界面添加了联系人信息，即persons不为空指针
        flag = intent.getBooleanExtra("flag", false);
        if (flag) {
   
            for (int i = 0; i < persons.size(); i++) {
   
                HashMap<String, Object> map = new HashMap<String, Object>();
                map.put("imgid", persons.get(i).getImgid());
                map.put("name", persons.get(i).getName());
                map.put("tel", persons.get(i).getTel());
                lxrList.add(map);
            }
            String[] from = {
   "imgid", "name", "tel"};
            int[] to = {
   R.id.lxrimg, R.id.lxrname, R.id.lxrtel};
            adapter = new SimpleAdapter(this, lxrList, R.layout.item, from, to);
            lv.setAdapter(adapter);
        }
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
   
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
   
                Intent itdail = new Intent(Intent.ACTION_CALL, Uri.parse("tel:"+persons.get(position).getTel()) );
                MainActivity.this.startActivity(itdail);
            }
        });
        // 添加监听事件
        add.setOnClickListener(new View.OnClickListener() {
   
            @Override
            public void onClick(View view) {
   
                Intent intent = new Intent(MainActivity.this, add_layout.class);
                startActivity(intent);
            }
        });
    }

    void initView() {
   
        lv = this.findViewById(R.id.lv);
        add = this.findViewById(R.id.tvadd);
    }
}

add_layout.java(添加联系人功能代码)

package com.example.ceshi;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.util.ArrayList;

public class add_layout extends AppCompatActivity {
   
    EditText edtName, edtTel;
    ImageView imgReturn, imgLeft, imgRight, img;
    int imgId[] = {
    R.mipmap.liubei,R.mipmap.caocao,R.mipmap