I'm trying to build a "Note taking" area in my app. I'm having problems with the view binding specifically. i followed this code example "https://codingwithsaud.medium.com/how-to-make-note-app-in-android-studio-part-1-443ccf16921e" to a T, but its mainly built in an activity not a fragment. I'm currently building it in an fragment and everything else is good besides my "Equipment_Tracker.kt" i cant figure out whats going wrong. The list problems take place in the "Equipment_Tracker.kt" Thanks in advance for helping.
List off errors popping up.
Unresolved reference: setContentView
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Type mismatch: inferred type is Equipment_Tracker but Context? was expected
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
None of the following functions can be called with the arguments supplied:
public constructor Intent(p0: Context!, p1: Class<*>!) defined in android.content.Intent
public constructor Intent(p0: String!, p1: Uri!) defined in android.content.Intent
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
Smart cast to 'FragmentEquipmentTrackerBinding' is impossible, because 'binding' is a mutable property that could have been changed by this time
None of the following functions can be called with the arguments supplied:
public open fun makeText(p0: Context!, p1: CharSequence!, p2: Int): Toast! defined in android.widget.Toast
public open fun makeText(p0: Context!, p1: Int, p2: Int): Toast! defined in android.widget.Toast
None of the following functions can be called with the arguments supplied:
public open fun makeText(p0: Context!, p1: CharSequence!, p2: Int): Toast! defined in android.widget.Toast
public open fun makeText(p0: Context!, p1: Int, p2: Int): Toast! defined in android.widget.Toast
Equipment_Tracker.kt
package com.example.armymaintenance
import android.content.Intent
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.fragment.app.Fragment
import com.example.armymaintenance.Model.note_model
import com.example.armymaintenance.database.MySqliteHelper
import com.example.armymaintenance.databinding.FragmentEquipmentTrackerBinding
class Equipment_Tracker : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_equipment__tracker, container, false)
}
var binding: FragmentEquipmentTrackerBinding? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = FragmentEquipmentTrackerBinding.inflate(layoutInflater)
setContentView(binding.getRoot())
val helper = MySqliteHelper(this)
binding.btnDisplay.setOnClickListener(View.OnClickListener {
val intent = Intent(this@Equipment_Tracker, Equipment_Tracker::class.java)
startActivity(intent)
})
binding.btnSave.setOnClickListener(View.OnClickListener {
val model = note_model()
model.bumpernumber = binding.bumpernumber.text.toString()
model.description = binding.description.text.toString()
model.nsn = binding.nsn.text.toString()
model.serialnumber = binding.serialnumber.text.toString()
model.date = binding.date.text.toString()
if (model.bumpernumber.isEmpty()) {
binding.bumpernumber.error = "Enter bumper number"
return@OnClickListener
}
if (model.description.isEmpty()) {
binding.description.error = "Enter description"
return@OnClickListener
}
if (model.nsn.isEmpty()) {
binding.nsn.error = "Enter nsn"
return@OnClickListener
}
if (model.serialnumber.isEmpty()) {
binding.serialnumber.error = "Enter serial number"
return@OnClickListener
}
if (model.date.isEmpty()) {
binding.date.error = "Enter date"
return@OnClickListener
}
val r = helper.saveNote(model)
if (r) {
Toast.makeText(this@Equipment_Tracker, "note is saved", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(this@Equipment_Tracker, "some thing want wrong", Toast.LENGTH_SHORT)
.show()
}
})
}
}
fragment_equipment_tracker.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
tools:context=".Equipment_Tracker">
<LinearLayout
android:layout_centerInParent="true"
android:padding="10dp"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@ id/bumpernumber"
android:hint="Bumper Number"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<EditText
android:id="@ id/description"
android:hint="Enter description"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<EditText
android:id="@ id/nsn"
android:hint="Enter nsn"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<EditText
android:id="@ id/serialnumber"
android:hint="Enter serial number"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<EditText
android:id="@ id/date"
android:hint="Enter date"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<Button
android:id="@ id/btnSave"
android:text="Save"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<Button
android:id="@ id/btnDisplay"
android:text="Display"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
</RelativeLayout>
note_model.java
package com.example.armymaintenance.Model;
public class note_model {
private int id;
private String bumpernumber;
private String description;
private String nsn;
private String serialnumber;
private String date;
public note_model() {
}
public note_model(int id, String bumpernumber, String description, String nsn, String serialnumber, String date) {
this.id = id;
this.bumpernumber = bumpernumber;
this.description = description;
this.nsn = nsn;
this.serialnumber = serialnumber;
this.date = date;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getBumpernumber() {
return bumpernumber;
}
public void setBumpernumber(String bumpernumber) {
this.bumpernumber = bumpernumber;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getNsn() {
return nsn;
}
public void setNsn(String nsn) {
this.nsn = nsn;
}
public String getSerialnumber() {
return serialnumber;
}
public void setSerialnumber(String serialnumber) {
this.serialnumber = serialnumber;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
}
MySqliteHelper.java
package com.example.armymaintenance.database;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
import com.example.armymaintenance.Model.note_model;
import java.util.ArrayList;
import java.util.List;
public class MySqliteHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME="note.db";
private static final int VERSION=1;
public MySqliteHelper(@Nullable Context context) {
super(context, DATABASE_NAME, null, VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
String table1="create table " TableSchema.note.TABLE_NAME "(" TableSchema.note.ID " INTEGER PRIMARY KEY AUTOINCREMENT, " TableSchema.note.BUMPERNUMBER " TEXT, " TableSchema.note.DESCRIPTION " TEXT," TableSchema.note.NSN " TEXT," TableSchema.note.SERIALNUMBER " TEXT, " TableSchema.note.DATE " TEXT );";
sqLiteDatabase.execSQL(table1);
}
public boolean saveNote(note_model model){
SQLiteDatabase database=this.getWritableDatabase();
ContentValues cv=new ContentValues();
cv.put(TableSchema.note.BUMPERNUMBER,model.getBumpernumber());
cv.put(TableSchema.note.DESCRIPTION,model.getDescription());
cv.put(TableSchema.note.NSN,model.getNsn());
cv.put(TableSchema.note.SERIALNUMBER,model.getSerialnumber());
cv.put(TableSchema.note.DATE,model.getDate());
long id= database.insert(TableSchema.note.TABLE_NAME,null,cv);
if (id==-1){
return false;
}
return true;
}
public List<note_model> getAllNotes(){
SQLiteDatabase database= this.getReadableDatabase();
String[] cols={TableSchema.note.ID,TableSchema.note.BUMPERNUMBER,TableSchema.note.DESCRIPTION,TableSchema.note.NSN,TableSchema.note.SERIALNUMBER,TableSchema.note.DATE};
Cursor cursor=database.query(TableSchema.note.TABLE_NAME,cols,null,null,null,null,TableSchema.note.ID " DESC");
ArrayList<note_model> list=new ArrayList<>();
while (cursor.moveToNext()){
note_model model=new note_model();
model.setId(cursor.getInt(cursor.getColumnIndex(TableSchema.note.ID)));
model.setBumpernumber(cursor.getString(cursor.getColumnIndex(TableSchema.note.BUMPERNUMBER)));
model.setDescription(cursor.getString(cursor.getColumnIndex(TableSchema.note.DESCRIPTION)));
model.setNsn(cursor.getString(cursor.getColumnIndex(TableSchema.note.NSN)));
model.setSerialnumber(cursor.getString(cursor.getColumnIndex(TableSchema.note.SERIALNUMBER)));
model.setDate(cursor.getString(cursor.getColumnIndex(TableSchema.note.DATE)));
list.add(model);
}
cursor.close();
database.close();
return list;
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
if (i<i1){
sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " TableSchema.note.TABLE_NAME);
}
}
}
TableSchema.java
package com.example.armymaintenance.database;
public class TableSchema {
public static class note{
public static final String TABLE_NAME="tbl_note";
public static final String ID="id";
public static final String BUMPERNUMBER="bumpernumber";
public static final String DESCRIPTION="description";
public static final String NSN="nsn";
public static final String SERIALNUMBER="serialnumber";
public static final String DATE="date";
}
}
CodePudding user response：
Binding is wrong Please check this documentation for the view Binding https://developer.android.com/topic/libraries/view-binding#kts
In Activity you can initialize the lateinit var binding: ActivityMainBinding
and can inflate the view like this
binding = ActivityMainBinding.inflate(layoutInflater)
val view = binding.root
setContentView(view)
But for the fragments the way is different
private var _binding: FragmentMainBinding? = null
private val binding get() = _binding!!
and in onCreateView method you have to do it like this
_binding = FragmentMainBinding.inflate(inflater, container, false)
val view = binding.root
return view
Please make sure that you do it in onCreateView not in onViewCreated
and in onDestroyView you have to set its value to null
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
That is the Proper way of doing binding you can also visit the documentation for more information