【Android Studio】图书管理系统——功能实现原理

概述使用框架采用了MVVM框架，即ModelViewViewModel模式Model：接收后端发送的实体数据ViewModel：处理Model的数据并发送给ViewView：展示处理好的数据   项目结构    具体实例逻辑层在ReaderClientApplication.kt文件中定义token以及一个全局contextclassReader 使用框架

采用了MVVM框架，即Model VIEw viewmodel模式

Model：接收后端发送的实体数据

viewmodel：处理Model的数据并发送给VIEw

VIEw：展示处理好的数据

 

 

 

项目结构

 

 

 

 

具体实例逻辑层

在ReaderClIEntApplication.kt文件中定义token以及一个全局context

class ReaderClIEntApplication: Application() {     var TOKEN = ""    companion object{        @Suppresslint("StaticFIEldLeak")        lateinit var context: Context    }    overrIDe fun onCreate() {        super.onCreate()        context = applicationContext        TOKEN = TOKEN    }}

　同时还需要在AndroIDManifest.xml中注册

<application        androID:name=".ReaderClIEntApplication"        androID:allowBackup="true"        androID:icon="@drawable/logo"        androID:label="@string/app_name"        androID:roundIcon="@mipmap/ic_launcher_round"        androID:supportsRtl="true"        androID:theme="@style/Apptheme">    .......</application>

　　

根据返回的Json格式，定义数据模型

model中的UserResponse.kt

data class UserResponse (val code: String, val data: UserData, val msg: String)data class UserData(val admin: Int, val borrowCount: Int, val major: String, val password: String, val sno: String, val username: String)data class User(val sno: String, val password: String)

　　

定义访问后端提供的API的接口

network中的BookService

interface BookService {    @POST("user/login")    fun loginValIDate(@Body user: User ): Call<UserResponse>......//其它接口}

　　

创建Retrofit构建器

network中的ServiceCreator

package com.example.readerclIEnt.logic.networkimport retrofit2.Retrofitimport retrofit2.converter.gson.GsonConverterFactoryobject ServiceCreator {    //后端服务基础地址    private const val BASE_URL = "http://172.27.183.4:8080/aissm_war_exploded/"    private val retrofit = Retrofit.Builder()        .baseUrl(BASE_URL)        .addConverterFactory(GsonConverterFactory.create())        .build()    fun<T> create(serviceClass: Class<T>): T = retrofit.create(serviceClass)    inline fun <reifIEd T> create(): T = create(T::class.java)}

 

定义统一网络数据源 访问入口

object ReaderClIEntNetwork {    private val BookService = ServiceCreator.create(BookService::class.java)    suspend fun loginValIDate(sno: String, password: String) = BookService.loginValIDate(User(sno, password)).await()......//其它方法    private suspend fun <T> Call<T>.await(): T{        return suspendCoroutine {                continuation -> enqueue(object : Callback<T> {            overrIDe fun onResponse(call: Call<T>, response: Response<T>) {                val body = response.body()                if(body != null) continuation.resume(body)                else continuation.resumeWithException(                    RuntimeException("response body is null")                )            }            overrIDe fun onFailure(call: Call<T>, t: Throwable) {                continuation.resumeWithException(t)            }        })        }    }}

　　

创建仓库层的统一封装入口

Repository单例类

object Repository {    fun loginValIDate(sno: String, password: String) = liveData(dispatchers.IO){        //var userResponse = UserResponse("", UserData(0, 0 ,"", "", "", ""), "")        val result = try{            val userResponse = ReaderClIEntNetwork.loginValIDate(sno, password)            if(userResponse.code == "0") {                Result.success(userResponse)            }else{                Result.failure(RuntimeException("Response status is ${userResponse.code}, msg: ${userResponse.msg}"))            }        }catch(e: Exception){            Result.failure<List<String>>(e)        }        //Log.d("userResponse code is:", result.toString())        //Log.d("userResponse code is:", userResponse.toString())        emit(result)    }......//其它方法}

　　

定义viewmodel层

ui/login中的Userviewmodel

class Userviewmodel: viewmodel() {    private val loginliveData = mutablelivedata<User>()    val userliveData = transformations.switchMap(loginliveData){        user -> Repository.loginValIDate(user.sno, user.password)    }    fun loginValIDate(sno: String, password: String){        loginliveData.value = User(sno, password)    }}

　　

UI层

创建activity_login.xml布局文件

<?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"    tools:context=".ui.login.LoginActivity">    <ImageVIEw        androID:ID="@+ID/imageVIEw"        androID:layout_wIDth="match_parent"        androID:layout_height="200dp"        androID:paddingtop="50dp"        androID:paddingBottom="50dp"        app:srcCompat="@drawable/logo" />    <linearLayout        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:orIEntation="horizontal">        <TextVIEw            androID:ID="@+ID/account"            androID:layout_wIDth="wrap_content"            androID:layout_height="wrap_content"            androID:text="账号" />        <EditText            androID:ID="@+ID/accountEdit"            androID:layout_wIDth="wrap_content"            androID:layout_height="wrap_content"            androID:layout_weight="1"            androID:ems="10"            androID:inputType="textPersonname" />    </linearLayout>    <linearLayout        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:orIEntation="horizontal">        <TextVIEw            androID:ID="@+ID/password"            androID:layout_wIDth="wrap_content"            androID:layout_height="wrap_content"            androID:text="密码" />        <EditText            androID:ID="@+ID/passwordEdit"            androID:layout_wIDth="wrap_content"            androID:layout_height="wrap_content"            androID:layout_weight="1"            androID:ems="10"            androID:inputType="textPassword" />    </linearLayout>    <button        androID:ID="@+ID/loginBtn"        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:text="登录" /></linearLayout>

 

创建LoginActivity文件

class LoginActivity : AppCompatActivity() {    overrIDe fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        setContentVIEw(R.layout.activity_login)        val viewmodel by lazy{ viewmodelProvIDers.of(this).get(Userviewmodel::class.java)}        val prefs = getSharedPreferences("data", Context.MODE_PRIVATE)        var today = Calendar.getInstance().get(Calendar.DAY_OF_YEAR);        var lastday = prefs.getInt("lastday", today)        var attempt = prefs.getInt("attempt", 0)        accountEdit.setText(prefs.getString("account", ""))        //Toast.makeText(this, "${today}   ${lastday}", Toast.LENGTH_SHORT).show()        //判断今日密码输入次数        if(today == lastday)        {            if( attempt >= 100) {                Toast.makeText(this, "已达今天最大尝试次数，请再重试", Toast.LENGTH_SHORT).show()                this.finish()            }        }else{            attempt = 0            lastday = today        }        var flag = 1        //登录按钮        loginBtn.setonClickListener(){            val account = accountEdit.text.toString()            val password = passwordEdit.text.toString()            val editor = prefs.edit()            val intent = Intent(this, MainActivity::class.java)            var userResponse : UserResponse            editor.putInt("lastday", lastday)            viewmodel.loginValIDate(account, password)            viewmodel.userliveData.observe(this, Observer{                    result ->                if(result.getorNull() != null){                    userResponse = result.getorNull() as UserResponse                    Log.d("testing",result.toString())                    Log.d("testing",userResponse.toString())                    editor.putString("account", account)                    if(userResponse.code.toInt() == 0){                        editor.putString("token", userResponse.msg)                        val user = userResponse.data                        if(password == user.password) {                            editor.putString("name", user.username)                            editor.putString("sno", user.sno)                            editor.putString("major", user.major)                            editor.apply()                            this.finish()                            startActivity(intent)                        }                    }                    else{                        Toast.makeText(this, userResponse.msg, Toast.LENGTH_SHORT).show()                    }                }            })        }    }}

　　

运行结果

 

总结

以上是内存溢出为你收集整理的【Android Studio】图书管理系统——功能实现原理全部内容，希望文章能够帮你解决【Android Studio】图书管理系统——功能实现原理所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。