# Can some one please help me.This code is not error but it does not show display

**URL:** <https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758>\
**Category:** Support\
**Created:** [August 12, 2020, 6:13pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758 "2020-08-12T18:13:04Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Hakuryuuu](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/hakuryuuu/32/7828_2.png) [@Hakuryuuu](https://discuss.kotlinlang.org/u/Hakuryuuu)\
**Post date:** [August 12, 2020, 6:13pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/1 "2020-08-12T18:13:04Z")

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> **[GitHub - Hakuryuuu/UpdateFirstApp](https://github.com/Hakuryuuu/UpdateFirstApp)**
>
> Contribute to Hakuryuuu/UpdateFirstApp development by creating an account on GitHub.

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**Author:** ![Wasabi375](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/wasabi375/32/4741_2.png) [@Wasabi375](https://discuss.kotlinlang.org/u/Wasabi375)\
**Post date:** [August 12, 2020, 6:33pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/2 "2020-08-12T18:33:56Z")

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Can you explain what your problem is? What exactly are you expecting your code to do? What does it do instead?  
Also it would be helpful if you only share the relevant parts of the code. That way it’s far more likely that people actually want to help you. Going through someone else’s entire project is not that appealing.

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**Author:** ![Hakuryuuu](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/hakuryuuu/32/7828_2.png) [@Hakuryuuu](https://discuss.kotlinlang.org/u/Hakuryuuu)\
**Post date:** [August 12, 2020, 6:41pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/3 "2020-08-12T18:41:53Z")

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this is Mainactivity.kt

package com.example.android.navigation

import android.app.Activity  
import android.content.Intent  
import android.os.Bundle  
import android.widget.Toast  
import androidx.appcompat.app.AppCompatActivity  
import androidx.databinding.DataBindingUtil  
import androidx.drawerlayout.widget.DrawerLayout  
import androidx.lifecycle.Observer  
import androidx.lifecycle.ViewModelProvider  
import androidx.navigation.findNavController  
import androidx.navigation.ui.NavigationUI  
import androidx.recyclerview.widget.LinearLayoutManager  
import androidx.recyclerview.widget.RecyclerView  
import com.example.android.navigation.databinding.ActivityMainBinding  
import com.google.android.material.floatingactionbutton.FloatingActionButton

class MainActivity : AppCompatActivity() {  
private lateinit var drawerLayout: DrawerLayout  
private val newWordActivityRequestCode = 1  
private lateinit var wordViewModel: WordViewModel

```
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    val recyclerView = findViewById<RecyclerView>(R.id.recyclerview)
    val adapter = WordListAdapter(this)
    recyclerView.adapter = adapter
    recyclerView.layoutManager = LinearLayoutManager(this)

    // Get a new or existing ViewModel from the ViewModelProvider.
    wordViewModel = ViewModelProvider(this).get(WordViewModel::class.java)

    // Add an observer on the LiveData returned by getAlphabetizedWords.
    // The onChanged() method fires when the observed data changes and the activity is
    // in the foreground.
    wordViewModel.allWords.observe(this, Observer { words ->
        // Update the cached copy of the words in the adapter.
        words?.let { adapter.setWords(it) }
    })

    val fab = findViewById<FloatingActionButton>(R.id.fab)
    fab.setOnClickListener {
        val intent = Intent(this@MainActivity, NewWordActivity::class.java)
        startActivityForResult(intent, newWordActivityRequestCode)
    }
    val binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)

    drawerLayout = binding.drawerLayout

    val navController = this.findNavController(R.id.myNavHostFragment)

    NavigationUI.setupActionBarWithNavController(this, navController, drawerLayout)

    NavigationUI.setupWithNavController(binding.navView, navController)

}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)

    if (requestCode == newWordActivityRequestCode && resultCode == Activity.RESULT_OK) {
        data?.getStringExtra(NewWordActivity.EXTRA_REPLY)?.let {
            val word = Word(it)
            wordViewModel.insert(word)
        }
    } else {
        Toast.makeText(
                applicationContext,
                R.string.empty_not_saved,
                Toast.LENGTH_LONG).show()
    }
}

override fun onSupportNavigateUp(): Boolean {
    val navController = this.findNavController(R.id.myNavHostFragment)
    return NavigationUI.navigateUp(navController, drawerLayout)
}

```

}

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<div class="post-metadata">

**Author:** ![Hakuryuuu](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/hakuryuuu/32/7828_2.png) [@Hakuryuuu](https://discuss.kotlinlang.org/u/Hakuryuuu)\
**Post date:** [August 12, 2020, 6:43pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/4 "2020-08-12T18:43:24Z")

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and I add this recyclerView code to the MainActivity.kt.Display will not show on the phone screen

val recyclerView = findViewById(R.id.recyclerview)  
val adapter = WordListAdapter(this)  
recyclerView.adapter = adapter  
recyclerView.layoutManager = LinearLayoutManager(this)

```
    // Get a new or existing ViewModel from the ViewModelProvider.
    wordViewModel = ViewModelProvider(this).get(WordViewModel::class.java)

    // Add an observer on the LiveData returned by getAlphabetizedWords.
    // The onChanged() method fires when the observed data changes and the activity is
    // in the foreground.
    wordViewModel.allWords.observe(this, Observer { words ->
        // Update the cached copy of the words in the adapter.
        words?.let { adapter.setWords(it) }
    })

    val fab = findViewById<FloatingActionButton>(R.id.fab)
    fab.setOnClickListener {
        val intent = Intent(this@MainActivity, NewWordActivity::class.java)
        startActivityForResult(intent, newWordActivityRequestCode)
    }

```

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<div class="post-metadata">

**Author:** ![Hakuryuuu](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/hakuryuuu/32/7828_2.png) [@Hakuryuuu](https://discuss.kotlinlang.org/u/Hakuryuuu)\
**Post date:** [August 12, 2020, 6:56pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/5 "2020-08-12T18:56:01Z")

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I want to add navigation contact to my firstApp use only ViewModel and Room database

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**Author:** ![Beholder](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/beholder/32/2078_2.png) [@Beholder](https://discuss.kotlinlang.org/u/Beholder)\
**Post date:** [August 13, 2020, 12:03pm UTC](https://discuss.kotlinlang.org/t/can-some-one-please-help-me-this-code-is-not-error-but-it-does-not-show-display/18758/6 "2020-08-13T12:03:43Z")

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It’s specific to Android, not Kotlin. Also, don’t expect anyone will do your homework.