Почти готово.

compose/app/src/main/java/ru/ulstu/is/pmu/composeui/navigation/MainNavbar.kt

@@ -16,6 +16,7 @@ import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.Button
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.ExposedDropdownMenuBox
@@ -249,6 +250,14 @@ fun MainNavbar(navController: NavController) {
         ){
             if(currentScreen?.route == Screen.TankList.route){
                 DropDownList(navController)
+                Button(
+                    onClick = {
+                        val route = Screen.Constructor.route.replace("{id}", 0.toString())
+                        navController.navigate(route)
+                    }
+                ) {
+                    Text(text = "Добавить")
+                }
             }
             Navhost(navController)
         }

compose/app/src/main/java/ru/ulstu/is/pmu/tank/composeui/TankList.kt

@@ -113,6 +113,7 @@ fun ColumnItem(
             )
             {
                 tanks.forEach { tank ->
+                    if(tank.tankId != null){
                         key(tank.tankId) {
                             //val studentId = Screen.StudentView.route.replace("{id}", index.toString())
                             Card(
@@ -122,7 +123,7 @@ fun ColumnItem(
                                 modifier = Modifier
                                     .size(width = 200.dp, height = 250.dp)
                                     .padding(all = 5.dp)
-                                .clickable { onClick(tank.tankId!!) }
+                                    .clickable { onClick(tank.tankId) }
                             ) {
                                 Image(
                                     painter = painterResource(id = tank.image),
@@ -160,6 +161,7 @@ fun ColumnItem(
             }
         }
     }
+}
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -168,7 +170,6 @@ private fun TankList(
     listTanks: List<Tank>,
     onClick: (uid: Long) -> Unit,
     ) {
-
     LazyColumn(
         verticalArrangement = Arrangement.Bottom,
         modifier = Modifier.height(300.dp * numbers.size),

compose/app/src/main/java/ru/ulstu/is/pmu/tank/composeui/edit/TankEditViewModel.kt

@@ -1,5 +1,6 @@
 package ru.ulstu.`is`.pmu.tank.composeui.edit
 
+import android.util.Log
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
@@ -23,6 +24,7 @@ class TankEditViewModel(
     private val tankUid: Long = checkNotNull(savedStateHandle["id"])
 
     init {
+        Log.d("hi-hi", tankUid.toString())
         viewModelScope.launch {
             if (tankUid > 0) {
                 tankUiState = tankRepository.getTank(tankUid)

compose/app/src/main/java/ru/ulstu/is/pmu/tank/database/AppDatabase.kt

@@ -29,7 +29,7 @@ abstract class AppDatabase : RoomDatabase() {
     abstract fun userDao() : UserDao
 
     companion object {
-        private const val DB_NAME: String = "nine-db"
+        private const val DB_NAME: String = "ten-db"
 
         @Volatile
         private var INSTANCE: AppDatabase? = null

compose/app/src/main/java/ru/ulstu/is/pmu/tanks/composeui/Constructor.kt

@@ -1,6 +1,7 @@
 package ru.ulstu.`is`.pmu.tanks.composeui
 
 import android.content.res.Configuration
+import android.util.Log
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
@@ -73,11 +74,14 @@ fun Constructor(
 ){
     val coroutineScope = rememberCoroutineScope()
 
+    val tankUiState = tankEditViewModel.tankUiState
+    Log.d("hi-2", tankUiState.tankDetails.name)
+    
     levelDropDownViewModel.setCurrentLevel(tankEditViewModel.tankUiState.tankDetails.levelId ?: 1)
-    nationDropDownViewModel.setCurrentNation(tankEditViewModel.tankUiState.tankDetails.nationId ?: 1)
+    nationDropDownViewModel.setCurrentNation(tankUiState.tankDetails.nationId ?: 1)
 
     Constructor(
-        tankUiState = tankEditViewModel.tankUiState,
+        tankUiState = tankUiState,
         levelUiState = levelDropDownViewModel.levelUiState,
         levelsListUiState = levelDropDownViewModel.levelsListUiState,
         onLevelUpdate = levelDropDownViewModel::updateUiState,
@@ -107,16 +111,11 @@ private fun Constructor(
     onClick: () -> Unit,
     onUpdate: (TankDetails) -> Unit
 ) {
-    var tankName by remember { mutableStateOf(tankUiState.tankDetails.name) }
-    var price by remember { mutableStateOf(tankUiState.tankDetails.price.toString()) }
-
     //для работы выпадающего списка уровней
     var expandedLevels by remember { mutableStateOf(false) }
-    var selectedLevel by remember { mutableIntStateOf(1) }
 
     //для работы выпадающего списка наций
     var expandedNation by remember { mutableStateOf(false) }
-    var selectedNation by remember { mutableStateOf("СССР") }
 
     Column(
         verticalArrangement = Arrangement.spacedBy(35.dp),
@@ -153,7 +152,7 @@ private fun Constructor(
                     }
                     Column {
                         TextField(
-                            value = tankName,
+                            value = tankUiState.tankDetails.name,
                             placeholder = { Text(text = "Название", color = CustomDark) },
                             onValueChange = { onUpdate(tankUiState.tankDetails.copy(name = it)) },
                             modifier = Modifier
@@ -173,7 +172,7 @@ private fun Constructor(
                                     .menuAnchor() // menuAnchor modifier must be passed to the text field for correctness.
                                     .width(200.dp),
                                 readOnly = true,
-                                value = selectedLevel.toString(),
+                                value = levelUiState.level?.level.toString(),
                                 onValueChange = {},
                                 label = { Text("") },
                                 trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = expandedLevels) },
@@ -192,7 +191,6 @@ private fun Constructor(
                                     DropdownMenuItem(
                                         text = { Text(selectionOption.level.toString()) },
                                         onClick = {
-                                            selectedLevel = selectionOption.level
                                             onLevelUpdate(selectionOption)
                                             expandedLevels = false
                                         },
@@ -215,7 +213,7 @@ private fun Constructor(
                                     .menuAnchor() // menuAnchor modifier must be passed to the text field for correctness.
                                     .width(200.dp),
                                 readOnly = true,
-                                value = selectedNation,
+                                value = nationUiState.nation?.nationName ?: "",
                                 onValueChange = {},
                                 label = { Text("") },
                                 trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = expandedNation) },
@@ -234,7 +232,6 @@ private fun Constructor(
                                     DropdownMenuItem(
                                         text = { Text(selectionOption.nationName) },
                                         onClick = {
-                                            selectedNation = selectionOption.nationName
                                             onNationUpdate(selectionOption)
                                             expandedNation = false
                                         },
@@ -245,7 +242,7 @@ private fun Constructor(
                         }
                         Spacer(Modifier.height(10.dp))
                         TextField(
-                            value = price,
+                            value = tankUiState.tankDetails.price.toString(),
                             placeholder = { Text(text = "Стоимость", color = CustomDark) },
                             onValueChange = { onUpdate(tankUiState.tankDetails.copy(price = it.toInt())) },
                             modifier = Modifier
@@ -267,7 +264,7 @@ private fun Constructor(
                             containerColor = CustomOrange,
                             contentColor = Color.Black
                         ),
-                        onClick = {  }) {
+                        onClick = { onClick() }) {
                         //"${student.firstName} ${student.lastName}"
                         Text(text = stringResource(id = R.string.save_account_button), fontSize = 20.sp, fontWeight = FontWeight.Bold)
                     }