Project one:
<provider
android:name=".MyContentProvider"
android:authorities="com.example.xryapplication8.provider"
android:enabled="true"
android:exported="true"></provider>
ContentProvider:
class MyContentProvider : ContentProvider() {
private val studentDir = 0
private val studentItem = 1
private val authority = "com.example.xryapplication8.provider"
private var dbHelper : MyDatabaseHelper ?= null
private val uriMatcher by lazy {
val matcher = UriMatcher(UriMatcher.NO_MATCH)
matcher.addURI(authority,"student",studentDir)
matcher.addURI(authority,"student/#",studentItem)
matcher
}
override fun delete(uri: Uri, selection: String?, selectionArgs: Array<String>?) = dbHelper?.let {
val db = it. writableDatabase
val deletedRows = when(uriMatcher.match(uri)){
studentDir -> db.delete("Student",selection,selectionArgs)
studentItem -> {
val studentId = uri. pathSegments[1]
db.delete("Student","id = ?", arrayOf(studentId))
}
else -> 0
}
deletedRows
}?:0
override fun getType(uri: Uri) = when(uriMatcher.match(uri)) {
studentDir -> "vnd.android.cursor.dir/vnd.com.example.xryapplication8.provider.student"
studentItem -> "vnd.android.cursor.item/vnd.com.example.xryapplication8.provider.student"
else -> null
}
override fun insert(uri: Uri, values: ContentValues?) = dbHelper?.let {
val db = it. writableDatabase
val uriReturn = when(uriMatcher.match(uri)){
studentDir, studentItem->{
val newStuId = db.insert("Student",null,values)
Uri.parse("content://$authority/student/$newStuId")
}
else -> null
}
uriReturn
}
override fun onCreate() = context?.let{
dbHelper = MyDatabaseHelper(it,"Student.db",2)
true
}?: false
override fun query(
uri: Uri, projection: Array<String>?, selection: String?,
selectionArgs: Array<String>?, sortOrder: String?
) = dbHelper?.let {
val db = it. readableDatabase
val cursor = when(uriMatcher.match(uri)){
studentDir -> db.query("Student",projection,selection,selectionArgs,null,null,sortOrder)
studentItem -> {
val stuId = uri.pathSegments[1]
db.query("Student",projection,"id= ?", arrayOf(stuId),null,null,sortOrder)
}
else -> null
}
cursor
}
override fun update(
uri: Uri, values: ContentValues?, selection: String?,
selectionArgs: Array<String>?
) = dbHelper?.let {
val db = it. writableDatabase
val updatedRows = when(uriMatcher.match(uri)){
studentDir -> db.update("Student",values,selection,selectionArgs)
studentItem -> {
val studentId = uri. pathSegments[1]
db.update("Student",values,"id=?", arrayOf(studentId))
}
else ->0
}
updatedRows
}?:0
}
database:
class MyDatabaseHelper(val context: Context,name:String,version:Int) : SQLiteOpenHelper(context,name,null,version) {
private val createStudent = "create table Student (" +
"id integer primary key," +
"name text," +
"college text," +
"age integer," +
"phone integer)"
override fun onCreate(db: SQLiteDatabase?) {
db?.execSQL(createStudent)
}
override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
db?.execSQL("drop table if exists Student")
onCreate(db)
}
}
Project 2:
insert:
class xryActivity1 :AppCompatActivity() ,View.OnClickListener{
var stuId:String?=null
@SuppressLint("MissingInflatedId")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_xry1)
val button:Button = findViewById(R.id.button)
button. setOnClickListener (this)
}
override fun onClick(v: View?) {//increase
val uri = Uri.parse("content://com.example.xryapplication8.provider/student")
val editText1 : EditText = findViewById(R.id.editTextid)
val editText2 : EditText = findViewById(R.id.editTextname)
val editText3 : EditText = findViewById(R.id.editTextcollege)
val editText4 : EditText = findViewById(R.id.editTextage)
val editText5 : EditText = findViewById(R.id.editTextphone)
when(v?.id){
R.id.button -> {
val inputText1 = editText1. text. toString()
val inputText2 = editText2. text. toString()
val inputText3 = editText3. text. toString()
val inputText4 = editText4. text. toString()
val inputText5 = editText5. text. toString()
val values = contentValuesOf("id" to inputText1,"name" to inputText2,
"college" to inputText3,"age" to inputText4,"phone" to inputText5)
val newUri = contentResolver.insert(uri,values)
stuId = newUri?.pathSegments?.get(1)
val intent = Intent(this,MainActivity::class.java)
startActivityForResult(intent,1)
}
}
}
}
Inquire:
class xryActivity2 :AppCompatActivity(),AdapterView.OnItemClickListener {
private val list = ArrayList<student>()
@SuppressLint("Range")
override fun onCreate(savedInstanceState:Bundle?){
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_recyclerview)
val listview:ListView = findViewById(R.id.listView)
val adapter = StuAdapter(R.layout.item,list,this)
listview.adapter = adapter
listview.setOnItemClickListener(this)
val uri = Uri.parse("content://com.example.xryapplication8.provider/student")
contentResolver.query(uri,null,null,null,null)?.apply {
while(moveToNext()){//find
val name = getString(getColumnIndex("name"))
val id = getInt(getColumnIndex("id"))
val college = getString(getColumnIndex("college"))
val stu = student(name, id, college)
list. add(stu)
}
close()
}
}
override fun onItemClick(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
val stus = list[position]
val intent = Intent(this,xryActivity3::class.java)
intent. putExtra("stu_id", stus. id. toString())
startActivity(intent)
}
}
Modifications and deletions:
class xryActivity3 :AppCompatActivity(),View.OnClickListener{
@SuppressLint("MissingInflatedId")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_xry3)
val button1 :Button = findViewById(R.id.button01)
button1.setOnClickListener(this)
val button2: Button = findViewById(R.id.button02)
button2.setOnClickListener(this)
val textView:TextView = findViewById(R.id.textViewid)
textView.text = intent.getStringExtra("stu_id").toString()
}
override fun onClick(v: View?) {
val studentId = intent. getStringExtra("stu_id")
val textView:TextView =findViewById(R.id.textViewid)
textView.text=studentId
val editText1: EditText = findViewById(R.id.editTextname)
val editText2: EditText = findViewById(R.id.editTextcollege)
val editText3: EditText = findViewById(R.id.editTextage)
val editText4: EditText = findViewById(R.id.editTextphone)
when(v?.id){
R.id.button01 ->{//Modify
studentId?.let {
val inputText1 = editText1. text. toString()
val inputText2 = editText2. text. toString()
val inputText3 = editText3. text. toString()
val inputText4 = editText4. text. toString()
val uri = Uri.parse("content://com.example.xryapplication8.provider/student/$it")
val values = contentValuesOf("name" to inputText1,"college" to inputText2,
"age" to inputText3,"phone" to inputText4)
contentResolver. update(uri, values, null, null)
val intent = Intent(this,xryActivity2::class.java)
startActivityForResult(intent,1)
}
}
R.id.button02 ->{//delete
studentId?.let {
val uri = Uri.parse("content://com.example.xryapplication8.provider/student/$it")
contentResolver.delete(uri,null,null)
val intent = Intent(this,xryActivity2::class.java)
startActivityForResult(intent,1)
}
}
}
}
}
student:
class student (var name:String,var id:Int,var college:String)
Adapter:
class StuAdapter(var resourceId:Int,var stulist:ArrayList<student>,var context: Context):
BaseAdapter() {
@SuppressLint("MissingInflatedId")
override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
var v: View = LayoutInflater.from(context).inflate(R.layout.item, null)
val model: student = stulist[position]
val name: TextView = v.findViewById(R.id.studentname)
val id: TextView = v.findViewById(R.id.studentid)
val college: TextView = v.findViewById(R.id.studentcollege)
name.text = model.name
id.text = model.id.toString()
college.text = model.college
return v
}
override fun getCount(): Int {
return stulist.size
}
override fun getItem(position: Int): student? {
return stulist[position]
}
override fun getItemId(position: Int): Long {
return 0
}
}
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