项目简介
本项目是对本人Android学习的一个汇总，集合使用了大部分以前博客所写的技术，是一个完整的Android项目。
语言环境：Kotlin
框架：MVVM
使用的技术：
第三方库：Retrofit
JetPack：ROOM Database、Navigation Component、Data Binding、ViewModel、AndroidViewModel、LiveData、Recyclerview、Kotlin Coroutines
API接口
⽹址：https://spoonacular.com/food-api
API Key: bfc03d044f1e42f8ab2e4031dfebcdea
完整的api接口：
https://api.spoonacular.com/recipes/complexSearch?type=main course&addRecipeInformation=true&cuisines=Chinese&fillIngredients=true&apiKey=bfc03d044f1e42f8ab2e4031dfebcdea&number=1
项目展示：
1.准备工作，解析json数据,创建基本类
使用插件JsonToKotlinClass
fragment模板
class RecipeFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_recipe, container, false)
}
}
2.第一步，搭建框架
使用Navigation，具体流程还可参考我的另一篇博客：https://www.jianshu.com/p/978951a2230f
基本流程：
1添加NavHost
2.添加⻝谱、喜欢和谚语的Fragment
3.添加NavHostFragment
4.添加BottomNavigationView和menu
5.关联BottomNavigationView和NavController
6.关联ActionBar和NavController
7.使⽤视图绑定访问xml中的控件
3.第二步，对Fragment进行布局，并用RecyclerView实现条目
RecyclerView 用法及缓存原理及性能优化可参考我的另一篇博客：https://www.jianshu.com/p/648e5ce98dfa
1.ShimmerRecyclerView的使⽤
2.ConstraintLayout约束布局使⽤
4.第三步，使用Okhttp和Retrofit进行数据请求
OkHttp、Gson、Retrofit的简单使用可参考我的另一篇博客：https://www.jianshu.com/p/b86bed8651d1
聚合数据API使⽤
OKHttp3请求数据
Gson解析Json数据
Json To Kotlin插件使⽤
Retrofit2请求数据的步骤
Service接口
interface FoodApi {
//服务器地址api.spoonacular.com/recipes/complexSearch
@GET("/recipes/complexSearch?fillIngredients=true&number=10&apiKey=bfc03d044f1e42f8ab2e4031dfebcdea&number=1")
suspend fun fetchFoodRecipe(@Query("type")type: String): Response<FoodRecipe>
}
RemoteRepository
class RemoteRepository {
private val retrofit = Retrofit.Builder()
.baseUrl("https://api.spoonacular.com")
.addConverterFactory(GsonConverterFactory.create())
.build()
private val foodApi = retrofit.create(FoodApi::class.java)
suspend fun fetchFoodRecipe(type: String): Response<FoodRecipe>{
return foodApi.fetchFoodRecipe(type)
}
}
5.第四步，使用DataBinding进行数据和视图绑定显示美食条目并且封装网络类（sealed class）
通过url绑定图片数据，因为需要对url进行处理，所有使用@BindingAdapter注解
1.导入kotlin-kapt来使用@BindingAdapter
object FoodBindingAdapter {
@JvmStatic
@BindingAdapter("loadImageWithUrl")
fun loadImageWithUrl(imageView: ImageView,url: String){
Glide.with(imageView.context)
.load(url)
.into(imageView)
}
}
总结：数据刷新流程
封装网络状态
sealed class NetworkResult<T>(
val data: T? = null,
val message: String? = null){
class Success<T>(data: T): NetworkResult<T>(data)
class Error<T>(errMsg: String):NetworkResult<T>(message = errMsg)
class Loading<T>: NetworkResult<T>()
}
6.第五步，使用room达到数据持久化
//数据仓库：实现数据的存取等
class LocalRepository(context: Context) {
private val recipeDao = RecipeDatabase.getDatabase(context).getRecipeDao()
//插入数据,重复则替换
suspend fun insertRecipe(recipeEntity: RecipeEntity){
recipeDao.insertRecipe(recipeEntity)
}
//查询数据
fun getRecipes(type: String): Flow<List<RecipeEntity>>{
return recipeDao.getRecipes(type)
}
//更新数据
suspend fun updateRecipe(recipeEntity: RecipeEntity){
recipeDao.updateRecipe(recipeEntity)
}
}
@Dao
interface RecipeDao {
//插入数据,重复则替换
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertRecipe(recipeEntity: RecipeEntity)
//查询数据
@Query("select * from foodRecipeTable where type = :type")
fun getRecipes(type: String): Flow<List<RecipeEntity>>
//更新数据
@Update(onConflict = OnConflictStrategy.REPLACE)
suspend fun updateRecipe(recipeEntity: RecipeEntity)
}
@TypeConverters(RecipeTypeConverter::class)
@Database(entities = [RecipeEntity::class],version = 1)
abstract class RecipeDatabase: RoomDatabase() {
abstract fun getRecipeDao(): RecipeDao
companion object{
private var instance: RecipeDatabase? = null
@Synchronized
fun getDatabase(context: Context): RecipeDatabase{
instance?.let {
return it
}
return Room.databaseBuilder(context.applicationContext,
RecipeDatabase::class.java,"foodRecipe_database")
.build().apply {
instance = this
}
}
}
}
@Entity(tableName = "foodRecipeTable")
class RecipeEntity(
@PrimaryKey(autoGenerate = true)
val id: Int,
val type: String,
val recipe: FoodRecipe
)
class RecipeTypeConverter {
//foodRecipe -> String
@TypeConverter
fun foodRecipeToString(recipe: FoodRecipe): String{
return Gson().toJson(recipe)
}
@TypeConverter
fun stringToFoodRecipe(string: String): FoodRecipe{
return Gson().fromJson(string,FoodRecipe::class.java)
}
}
7.第六步，对Result类实现序列化来进行主页到详情页的信息传递
plugins {
id 'kotlin-parcelize'
}
@Parcelize
data class Result(
@SerializedName("aggregateLikes")
val aggregateLikes: Int,
@SerializedName("cheap")
val cheap: Boolean,
@SerializedName("cuisines")
val cuisines: List<String>,
@SerializedName("dairyFree")
val dairyFree: Boolean,
@SerializedName("extendedIngredients")
val extendedIngredients: List<ExtendedIngredient>,
@SerializedName("gaps")
val gaps: String
): Parcelable
nav_graph添加后在recyclerview的adapter中传递数据
class DetailFragment : Fragment() {
private lateinit var binding:FragmentDetailBinding
private val recipeArgs: DetailFragmentArgs by navArgs()
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = FragmentDetailBinding.inflate(inflater)
return binding.root
}
详情页中ViewPager的使用
遇到的问题：
dataBinding传递函数
recyclerview回调实现点击效果
view动画不改变view的真实位置
LayoutInflater中的的inflate方法
第一种方式填充视图，item布局中的根视图的layout_XX属性会被忽略掉，然后设置成默认的包裹内容方式
第二种方式，才会使用在xml中parent对viewHolder的约束对进行布局
