个人作业Android学习系统开发日志四

Android实现：
WeekGoals：
entity:

package com.example.learningmanagement.entity

data class WeekGoals(
    val id: Int,
    val weekNumber: Int,
    val title: String,
    val content: String,
    val userId: Int
)

adapter:

package com.example.learningmanagement.adapter

import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.ListAdapter
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.RecyclerView
import com.example.learningmanagement.entity.WeekGoals
import com.example.learningmanagement.databinding.ItemWeekGoalBinding


class WeekGoalsAdapter :
    ListAdapter<WeekGoals, WeekGoalsAdapter.ViewHolder>(WeekGoalsDiffCallback()) {

    class ViewHolder(private val binding: ItemWeekGoalBinding) :
        RecyclerView.ViewHolder(binding.root) {
        fun bind(weekGoal: WeekGoals) {
            binding.tvTitle.text = weekGoal.title
            binding.tvContent.text = weekGoal.content
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val binding = ItemWeekGoalBinding.inflate(
            LayoutInflater.from(parent.context), parent, false
        )
        return ViewHolder(binding)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bind(getItem(position))
    }
}

class WeekGoalsDiffCallback : DiffUtil.ItemCallback<WeekGoals>() {
    override fun areItemsTheSame(oldItem: WeekGoals, newItem: WeekGoals) = oldItem.id == newItem.id
    override fun areContentsTheSame(oldItem: WeekGoals, newItem: WeekGoals) = oldItem == newItem
}

service:

package com.example.learningmanagement.service

import com.example.learningmanagement.entity.ApiResponse
import com.example.learningmanagement.entity.WeekGoals
import retrofit2.http.Body
import retrofit2.http.DELETE
import retrofit2.http.GET
import retrofit2.http.POST
import retrofit2.http.Path

interface WeekGoalsService {
    @GET("weekGoals/selectAll/{userId}")
    suspend fun getWeekGoals(@Path("userId") userId: String): ApiResponse<List<WeekGoals>>
    
    @POST("weekGoals/add")
    suspend fun addWeekGoal(@Body weekGoal: WeekGoals): ApiResponse<WeekGoals>

    @DELETE("weekGoals/deleteById/{id}")
    suspend fun deleteWeekGoal(@Path("id") id: Int): ApiResponse<String>
}

fragment:

package com.example.learningmanagement.ui.fragment

import android.content.Context
import android.os.Bundle
import android.view.GestureDetector
import android.view.LayoutInflater
import android.view.MotionEvent
import android.view.View
import android.view.ViewGroup
import android.widget.Toast
import androidx.fragment.app.Fragment
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.learningmanagement.adapter.WeekGoalsAdapter
import com.example.learningmanagement.databinding.FragmentWeekGoalsBinding
import com.example.learningmanagement.network.ServiceCreater
import com.example.learningmanagement.service.WeekGoalsService
import com.example.learningmanagement.ui.MainActivity
import com.example.learningmanagement.utils.PrefsHelper
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.launch
import kotlinx.coroutines.isActive
import kotlin.math.abs

class WeekGoalsFragment : Fragment() {
    private var _binding: FragmentWeekGoalsBinding? = null
    private val binding get() = _binding!!
    private val weekGoalsService = ServiceCreater.create<WeekGoalsService>()
    private val weekGoalsAdapter = WeekGoalsAdapter()
    private lateinit var prefs: PrefsHelper

    // 添加滑动相关变量
    private lateinit var gestureDetector: GestureDetector
    private var allGoals = listOf<com.example.learningmanagement.entity.WeekGoals>()
    private var currentPosition = 0

    override fun onAttach(context: Context) {
        super.onAttach(context)
        prefs = PrefsHelper(context)
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentWeekGoalsBinding.inflate(inflater, container, false)

        // 初始化手势检测器
        gestureDetector =
            GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
                override fun onFling(
                    e1: MotionEvent?,
                    e2: MotionEvent,
                    velocityX: Float,
                    velocityY: Float
                ): Boolean {
                    if (e1 == null) return false

                    val diffX = e2.x - e1.x
                    val diffY = e2.y - e1.y

                    // 确保是水平滑动而不是垂直滑动
                    if (abs(diffX) > abs(diffY)) {
                        if (diffX > 0) {
                            // 向右滑动，显示上一条数据
                            showPreviousGoal()
                        } else {
                            // 向左滑动，显示下一条数据
                            showNextGoal()
                        }
                        return true
                    }
                    return false
                }
            })

        // 设置触摸监听器
        binding.root.setOnTouchListener { _, event ->
            gestureDetector.onTouchEvent(event)
            false
        }

        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        setupRecyclerView()
        loadWeekGoals()
    }

    private fun setupRecyclerView() {
        binding.rvWeekGoals.apply {
            layoutManager = LinearLayoutManager(context)
            adapter = weekGoalsAdapter
        }
    }

    // 显示上一条数据
    private fun showPreviousGoal() {
        if (allGoals.isEmpty()) return

        if (currentPosition > 0) {
            currentPosition--
            updateDisplay()
        } else {
            showToast("已经是第一条数据")
        }
    }

    // 显示下一条数据
    private fun showNextGoal() {
        if (allGoals.isEmpty()) return

        if (currentPosition < allGoals.size - 1) {
            currentPosition++
            updateDisplay()
        } else {
            showToast("已经是最后一条数据")
        }
    }

    // 更新显示
    private fun updateDisplay() {
        if (allGoals.isEmpty() || !isAdded || _binding == null) return

        val currentGoal = allGoals[currentPosition]

        // 更新RecyclerView显示当前选中的目标
        weekGoalsAdapter.submitList(listOf(currentGoal))

        // 更新主活动中的周数标题
        (activity as? MainActivity)?.updateWeekTitle("第${currentGoal.weekNumber}周")
    }

    private fun loadWeekGoals() {
        if (!isAdded) return

        lifecycleScope.launch {
            try {
                val userId = prefs.getUserId()
                userId?.let { id ->
                    try {
                        if (!isActive) return@launch

                        val response = weekGoalsService.getWeekGoals(id)

                        if (!isActive || !isAdded || _binding == null) return@launch

                        if (response.code == "200") {
                            response.data?.let { goals ->
                                if (goals.isNotEmpty()) {
                                    // 保存所有目标数据
                                    allGoals = goals.sortedByDescending { it.weekNumber }

                                    // 默认显示最新的数据（第一条）
                                    currentPosition = 0
                                    updateDisplay()

                                    // 显示RecyclerView
                                    binding.rvWeekGoals.visibility = View.VISIBLE
                                    binding.tvEmptyData.visibility = View.GONE
                                } else {
                                    allGoals = emptyList()
                                    weekGoalsAdapter.submitList(emptyList())
                                    showEmptyView()
                                }
                            } ?: run {
                                allGoals = emptyList()
                                weekGoalsAdapter.submitList(emptyList())
                                showEmptyView()
                            }
                        } else {
                            showToast("获取数据失败: ${response.msg}")
                            showEmptyView()
                        }
                    } catch (e: CancellationException) {
                        android.util.Log.d("WeekGoalsFragment", "协程已取消")
                    } catch (e: Exception) {
                        if (!isActive || !isAdded || _binding == null) return@launch

                        val errorMessage = "网络请求错误: ${e.javaClass.simpleName} - ${e.message}"
                        showToast(errorMessage)
                        android.util.Log.e("WeekGoalsFragment", errorMessage, e)
                        showEmptyView()
                    }
                } ?: run {
                    if (!isActive || !isAdded || _binding == null) return@launch

                    showToast("用户未登录")
                    showEmptyView()
                }
            } catch (e: CancellationException) {
                android.util.Log.d("WeekGoalsFragment", "协程已取消")
            } catch (e: Exception) {
                if (!isActive || !isAdded || _binding == null) return@launch

                val errorMessage = "加载失败: ${e.javaClass.simpleName} - ${e.message}"
                showToast(errorMessage)
                android.util.Log.e("WeekGoalsFragment", errorMessage, e)
                showEmptyView()
            }
        }
    }

    private fun showToast(message: String) {
        if (isAdded && activity != null) {
            activity?.let {
                Toast.makeText(it, message, Toast.LENGTH_SHORT).show()
            }
        }
    }

    private fun showEmptyView() {
        if (!isAdded || _binding == null) return

        (activity as? MainActivity)?.updateWeekTitle("周目标")
        binding.tvEmptyData.visibility = View.VISIBLE
        binding.rvWeekGoals.visibility = View.GONE
    }

    override fun onDestroyView() {
        super.onDestroyView()
        _binding = null
    }

    fun refreshData() {
        if (isAdded && _binding != null) {
            loadWeekGoals()
        }
    }

    // 在类中添加删除方法
    fun deleteCurrentGoal() {
        if (allGoals.isEmpty() || currentPosition < 0 || currentPosition >= allGoals.size) {
            showToast("没有可删除的数据")
            return
        }

        val currentGoal = allGoals[currentPosition]

        // 显示确认对话框
        context?.let { ctx ->
            androidx.appcompat.app.AlertDialog.Builder(ctx)
                .setTitle("确认删除")
                .setMessage("确定要删除第${currentGoal.weekNumber}周的目标吗？")
                .setPositiveButton("确定") { _, _ ->
                    performDelete(currentGoal.id)
                }
                .setNegativeButton("取消", null)
                .show()
        }
    }

    // 执行删除操作
    private fun performDelete(goalId: Int) {
        lifecycleScope.launch {
            try {
                if (!isActive || !isAdded || _binding == null) return@launch

                // 显示加载提示
                showToast("正在删除...")

                val response = weekGoalsService.deleteWeekGoal(goalId)

                if (!isActive || !isAdded || _binding == null) return@launch

                if (response.code == "200") {
                    showToast("删除成功")

                    // 从列表中移除已删除的项
                    val newList = allGoals.toMutableList()
                    newList.removeAt(currentPosition)
                    allGoals = newList

                    // 调整当前位置
                    if (allGoals.isEmpty()) {
                        // 如果删除后没有数据了
                        currentPosition = -1
                        showEmptyView()
                    } else {
                        // 如果删除的是最后一项，则显示新的最后一项
                        if (currentPosition >= allGoals.size) {
                            currentPosition = allGoals.size - 1
                        }
                        updateDisplay()
                    }
                } else {
                    showToast("删除失败: ${response.msg}")
                }
            } catch (e: CancellationException) {
                android.util.Log.d("WeekGoalsFragment", "协程已取消")
            } catch (e: Exception) {
                if (!isActive || !isAdded || _binding == null) return@launch

                val errorMessage = "删除失败: ${e.javaClass.simpleName} - ${e.message}"
                showToast(errorMessage)
                android.util.Log.e("WeekGoalsFragment", errorMessage, e)
            }
        }
    }
}

xml:

<?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">

    <!-- 顶部标题栏 -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/pink_500"
        android:gravity="center_vertical"
        android:paddingHorizontal="16dp">

        <!-- 周数标题 -->
        <TextView
            android:id="@+id/tvWeekTitle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="第15周"
            android:textColor="@color/white"
            android:textSize="20sp"
            android:textStyle="bold"/>

        <!-- 空白占位 -->
        <Space
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="1"/>

        <!-- 操作按钮组 -->
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:orientation="horizontal">

            <!-- 删除按钮 -->
            <ImageButton
                android:id="@+id/btnDelete"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:background="?attr/selectableItemBackgroundBorderless"
                android:src="@drawable/ic_delete_white"
                android:contentDescription="删除"
                app:tint="@color/white" />

            <!-- 修改按钮 -->
            <ImageButton
                android:id="@+id/btnEdit"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:background="?attr/selectableItemBackgroundBorderless"
                android:src="@drawable/ic_edit_white"
                android:contentDescription="修改"
                android:layout_marginStart="8dp"
                app:tint="@color/white" />

            <!-- 添加按钮 -->
            <ImageButton
                android:id="@+id/btnAdd"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:background="?attr/selectableItemBackgroundBorderless"
                android:src="@drawable/ic_add_white"
                android:contentDescription="添加"
                android:layout_marginStart="8dp"
                app:tint="@color/white" />
        </LinearLayout>
    </LinearLayout>

    <!-- 内容区域 -->
    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@drawable/bg_pink_gradient"/>

    <!-- 底部导航 -->
    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_nav"
        android:background="@color/pink_500"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:itemHorizontalTranslationEnabled="false"
        app:labelVisibilityMode="labeled"
        app:menu="@menu/bottom_nav_menu" />
</LinearLayout>

<?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="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/etWeekNumber"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="周数"
        android:inputType="number"
        android:maxLines="1"
        android:layout_marginBottom="8dp"/>

    <EditText
        android:id="@+id/etTitle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="标题"
        android:maxLines="1"
        android:layout_marginBottom="8dp"/>

    <EditText
        android:id="@+id/etContent"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="内容"
        android:minLines="3"
        android:gravity="top|start"
        android:inputType="textMultiLine"/>

</LinearLayout>

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvWeekGoals"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="8dp" />

    <TextView
        android:id="@+id/tvEmptyData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="暂无数据"
        android:textSize="18sp"
        android:textColor="#757575"
        android:visibility="gone" />

</FrameLayout>