如何从外部数据库（Kotlin）显示图像

Question

大家好，我想使用外部数据库制作应用程序，我用SQLite浏览器制作了数据库，将图像放在可绘制的情况下，我需要显示图像和文字 （图像也不显示这不是任何错误日志） 有关更多指导，我在适配器中有一些代码 我也放了gitlab链接 任何帮助都会很感激。谢谢

    class model {
        var id:Int?=null
        var name:String?=null
        var image:String?=null
    }

    object info_db {
    
        val dbName="country"
        val dbversion=2
        val dbId="id"
        val dbcname="name"
        val dbimage="image"
        val packageData="data/data/com.alialim.countrylist_sample/databases/"
        val source ="country.sqlite"
    
    }

    class Database(val context: Context): SQLiteOpenHelper(context,info_db.dbName,null,info_db.dbversion)  {
        override fun onCreate(p0: SQLiteDatabase?) {
        }
    
        override fun onUpgrade(p0: SQLiteDatabase?, p1: Int, p2: Int) {
    
        }
    
        init {
            initDatabase()
        }
        private fun initDatabase() {
    
            var file = File(info_db.packageData)
    
            if (file.exists()) {
    
            } else {
                file.mkdirs()
            }
    
            file = context.getDatabasePath(info_db.dbName)
            if (file.exists()) {
    
            } else {
                copyDataBase()
            }
    
        }
    
        private fun copyDataBase() {
            val inputStream = context.assets.open(source)
            val outFile = packageData + dbName
            val uotPutStream = FileOutputStream(outFile)
            val buffer = ByteArray(1024)
            var lenght = 0
            while (inputStream.read(buffer).also({ lenght = it }) > 0)
                uotPutStream.write(buffer, 0, lenght)
            uotPutStream.flush()
            uotPutStream.close()
            inputStream.close()
        }
    
        @SuppressLint("Range")
        fun getAll(): ArrayList<model> {
            val db = readableDatabase
            val query = "SELECT * FROM countrylist"
            var list: ArrayList<model> = ArrayList()
            val cursor = db.rawQuery(query, null)
            if (cursor.moveToFirst()) {
                do {
                    val lmodel = model()
                    lmodel.id=cursor.getInt(cursor.getColumnIndex(info_db.dbId))
                    lmodel.name=cursor.getString(cursor.getColumnIndex(info_db.dbcname))
    
                    lmodel.image=cursor.getString(cursor.getColumnIndex(info_db.dbimage))
                    list.add(lmodel)
                    Log.d(
                        "massage",
                        "log Database name ==>${lmodel.name} and category ==> ${lmodel.image}  "
                    )
                } while (cursor.moveToNext())
            }
            cursor.close()
            db.close()
            return list
        }
    }

    object Base: Application() {
        var database: Database?=null
        var activity: Activity?=null
    
        override fun onCreate() {
            super.onCreate()
        }
    }

    class AdapterCountry(val context: Context, val countrylists:ArrayList<model>): RecyclerView.Adapter<AdapterCountry.HolderCountry>() {
    
        class HolderCountry(itemView: View): RecyclerView.ViewHolder(itemView){
            val imagerecy=itemView.findViewById<ImageView>(R.id.recycler_main_image)
            val txtfname=itemView.findViewById<TextView>(R.id.recycler_main_text)
    
        }
    
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HolderCountry {
            val layout= LayoutInflater.from(parent.context).inflate(R.layout.item,parent,false)
            return HolderCountry(layout)
        }
        override fun onBindViewHolder(holder: HolderCountry, position: Int) {
            val countrylist=countrylists.get(position)
            holder.txtfname.text=countrylist.name
            //code that should display the images but dosent work
            val img=countrylist.image
            val Image: Int = Base.activity!!.getResources()
                .getIdentifier(img, "drawable", Base.activity!!.getPackageName())
            holder.imagerecy.setImageResource(Image)
            //////////////
        }
        override fun getItemCount()=countrylists.size
    }

    class MainActivity : AppCompatActivity() {
    
        var btnclick: Button?=null
        var recycler: RecyclerView?=null
        var adaptecounry: AdapterCountry?=null
    
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)
    
            btnclick=findViewById(R.id.showcountrye)
            recycler=findViewById(R.id.mainactivity_recy_image)
            Base.activity=this
            Base.database= Database(this)
            btnclick!!.setOnClickListener {
                recycler!!.setHasTransientState(true)
                recycler!!.layoutManager= LinearLayoutManager(Base.activity)
                val list= Base.database!!.getAll()
                adaptecounry = AdapterCountry(Base.activity!!,list)
                recycler!!.adapter=adaptecounry
    
            }
    
        }
    
    }

sqlitebrowser drawable

请访问： https://gitlab.com/salin1/country_list//tree/master/master

Answer 1

大家好，我可以解决我的问题，因为我还是很短的时间
我在这里写我的正确代码，也许有一天有人需要它，我的鳕鱼是正确的，但是您需要将此代码放入您的recyclerview适配器中，

   

override fun onBindViewHolder(holder: HolderCountry, position: Int) {

        val countrylist=countrylists.get(position)
        Log.i("imaaagee","${countrylist.image}")
        holder.txtfname.text=countrylist.name
        val img=countrylist.name
        img!!.trim()
        val identifier=context.resources.getIdentifier(img,"drawable",
        context!!.getPackageName())
        holder.imagerecy.setImageResource(identifier)

    }

我还会在图像列中查看我在图像列中看到的数据库图像，我也会放置链接和图像。带有格式（.png）的图像名称，但它的错误，因为GetIdentifier不需要图像格式，您应该做的所有事情就是将图像放置在可绘制的地方，并使用适配器代码恢复
为了进一步了解，我放置了我的gitlab链接，您可以下载并查看代码
如果您有任何疑问，请问我会回答
谢谢