how to install apk file programmatically

Question

I want to install an apk file from my application.

I have created an app that contains a button, when I click that button then another apk that I have stored in res

Answer 1

This might help you. for Android 10 put this in Manifest.xml

android:requestLegacyExternalStorage="true"

MainActivity.kt

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.os.Environment
import android.os.StrictMode
import android.os.StrictMode.VmPolicy
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.FileProvider
import kotlinx.android.synthetic.main.activity_main.*
import java.io.File

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        test.setOnClickListener {
            val arrPerm: ArrayList = ArrayList()
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                arrPerm.add(Manifest.permission.WRITE_EXTERNAL_STORAGE)
            }
            if (arrPerm.isNotEmpty()) {
                var permissions = arrayOfNulls(arrPerm.size)
                permissions = arrPerm.toArray(permissions)
                ActivityCompat.requestPermissions(this, permissions, 1000)
            } else {

                requestapkInstallation()
// FileProvider.getUriForFile(this, applicationContext.packageName + ".provider",File("/storage/emulated/0/Download/test.apk"))
            }
        }
    }

    fun requestapkInstallation() {
        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.N) {
            val builder = VmPolicy.Builder()
            StrictMode.setVmPolicy(builder.build())
            val fileUri = FileProvider.getUriForFile(
                this,
                applicationContext.packageName + ".provider",
                File(Environment.getExternalStorageDirectory().toString() + "/download/" + "app-debug.apk")
            )
            val intent1 = Intent(Intent.ACTION_VIEW);
            intent1.setDataAndType(
                fileUri,
                "application/vnd.android.package-archive"
            );
            intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent1.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            intent1.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
            intent1.putExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, true)
            startActivity(intent1);
        } else {
            val fileUri = FileProvider.getUriForFile(
                this,
                applicationContext.packageName + ".provider",
                File(Environment.getExternalStorageDirectory().toString()+ "/download/" + "app-debug.apk")
            )
            val intent = Intent(Intent.ACTION_VIEW, fileUri)
            intent.putExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, true)
            intent.flags = Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
            intent.setDataAndType(fileUri, "application/vnd.android.package-archive")

            startActivity(intent)
        }
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array, grantResults: IntArray) {
    when(requestCode)
    {
        1000->{
            if(Manifest.permission.WRITE_EXTERNAL_STORAGE == permissions[0]) {
                if(grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // you now have permission
                    requestapkInstallation()
                }
            }
        }
    }
}

}