Login button is not working Android Kotlin

Question

I am creating a simple login form with SharedPreferences.I have put some basic user validation but it is not working. When I enter the username and password and click login button, nothing gets displayed. It should if it is wrong username and password. Below is the code for same.

  val userName = findViewById(R.id.user) as EditText
        val password = findViewById(R.id.pass) as EditText
        val b1 = findViewById(R.id.btn1) as Button

        b1.setOnClickListener {

            if (userName.equals("")  || password.equals(""))
            {
                Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
            }
            else if (userName.equals("John") and password.equals("123"))
            {
                val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
                editor.putString("name", userName.getText().toString())
                editor.apply()
                val intent = Intent(this, Main2Activity::class.java)
                intent.putExtra("name", userName.toString())
                startActivity(intent)

            }

      else
           {
            Toast.makeText(this, "Username or Password Do not Match", Toast.LENGTH_LONG).show()
           }


        }

Try like this `userName.text.equals("")` and `userName.text.equals("John")` — Anas Mehar, Nov 20 '19 at 05:59
Could you debug and check where the flow is going. Agree with Anas — Aditi, Nov 20 '19 at 05:59
use userName.text.equals at all places in your above code instead of simple userName.equals — Aditi, Nov 20 '19 at 06:05
userName.text.equals i used like all places of above code not working — thusy ram, Nov 20 '19 at 06:07
Please do not edit your question with fixes that answer your question, as it confuses everyone. I've undone your edit. — Ken Y-N, Nov 20 '19 at 06:18

score 1 · Answer 1 · answered Nov 20 '19 at 06:14

The matches will be the best option for this kind of validation things

sUsername = userName.text;
if (sUsername.matches("")) {
    Toast.makeText(this, "You did not enter a username", Toast.LENGTH_SHORT).show();
    return;
}

reference question : Check if EditText is empty.

score 0 · Answer 2 · answered Nov 20 '19 at 06:15

Try this one

if (userName.text.isNullOrEmpty()){
                userName.error = "Enter username"
            }
            else if (password.text.isNullOrEmpty()){
                password.error = "Enter password"
            }
            else if (userName.text.toString() == "john" && password.text.toString() == "123"){

                val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
                editor.putString("name", userName.getText().toString())
                editor.apply()
                val intent = Intent(this, Main2Activity::class.java)
                intent.putExtra("name", userName.toString())
                startActivity(intent)

            }

score 0 · Answer 3 · answered Nov 20 '19 at 06:16

b1.setOnClickListener {

            if (userName.text.toString().equals("") || password.text.toString().equals("")) {
                Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
            } else if (userName.text.toString().equals("John") and password.text.toString().equals("123")) {
                 val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
                            editor.putString("name", userName.getText().toString())
                            editor.apply()
                           val intent = Intent(this, Main2Activity::class.java)
                           intent.putExtra("name", userName.toString())
                           startActivity(intent)
            }
            else {
                Toast.makeText(this, "Username or Password Do not Match", Toast.LENGTH_LONG).show()
            }
        }

score 0 · Answer 4 · answered Nov 20 '19 at 06:16

b1.setOnClickListener {view ->

       if (userName.text.isNullOrEmpty()  || password.text.isNullOrEmpty()){
            Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
        }else if (userName.text.equals("John") and password.text.equals("123")){
            val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
            editor.putString("name", userName.getText().toString())
            editor.apply()
            val intent = Intent(this, Main2Activity::class.java)
            intent.putExtra("name", userName.toString())
            startActivity(intent)

        }

    }

score 0 · Answer 5 · answered Nov 20 '19 at 06:16

I assume you have added

apply plugin: 'kotlin-android-extensions'.

in your app level gradle. Using this there is not need to use findViewById. You can directly access views from layout.

So if you have Edittext with id edit.

then in your code you can directly use that as below

if(edit.text.isEmpty())
{
// Your code
}

or

if(edit.text.equals("")
{
// Your code
}

Hope it helps!

score 0 · Answer 6 · answered Nov 20 '19 at 06:17

This should work

b1.setOnClickListener {
    if (userName.text.isEmpty() || password.text.isEmpty())
    {
        Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
    }
    else if (userName.text == "John" && password.text == "123")
    {
        val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
        editor.putString("name", userName.getText().toString())
        editor.apply()
        val intent = Intent(this, Main2Activity::class.java)
        intent.putExtra("name", userName.toString())
        startActivity(intent)
    }
}

USMAN osman · Answer 7 · 2019-11-20T07:13:18.030

You are not converting your Edittext into string you have just assigned the id to your Edittext and it would still be treated as a Edittext field. You have to pass the string value, not a Editext. To convert it into string, your if condition must be like this:

 if (userName.text.toString().trim().equals("")  || password.text.toString().trim().equals("")) {
 Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
            }

Or you can do it while assigning the id, like so:

val uName = userName.text.toString().trim()
val userPass = password.text.toString().trim()

then your if condition will be like this:

if (uName.equals("")  || userPass.equals("")) {
 Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
            }

Jakir Hossain · Accepted Answer · 2019-11-20T06:23:19.730

Try like the following.

b1.setOnClickListener {
   val name:String = userName.text.toString()
   val pass:String = password.text.toString()

   if (name.trim().length == 0  || pass.trim().length == 0){
         Toast.makeText(this, "Username or Password blank", Toast.LENGTH_LONG).show()
   }
   else if (name.equals("John") and pass.equals("123")){
         val editor = getSharedPreferences("name", Context.MODE_PRIVATE).edit()
         editor.putString("name", name)
         editor.apply()
         val intent = Intent(this, Main2Activity::class.java)
         intent.putExtra("name", name)
         startActivity(intent)

   }
   else{
        Toast.makeText(this, "Username or Password Do not Match", Toast.LENGTH_LONG).show()
   }

}

Login button is not working Android Kotlin

8 Answers8