Phone Call Android

In questo esempio andiamo ad utilizzare Internet.ACTION_CALL per aggiungere un pulsante di chiamata su un applicazione, inserendo le autorizzazioni sul file Android Manifest:
<uses-permission android:name=”android.permission.CALL_PHONE”/>
activity_main.xml
<?xml version=”1.0″ encoding=”utf-8″?>

<LinearLayout
xmlns:android=”http://schemas.android.com/apk/res/android“
android:layout_width=”match_parent”
android:layout_height=”match_parent”
android:gravity=”center”
android:orientation=”vertical”>

<EditText
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:id=”@+id/txt”
android:hint=”Enter Number”
android:textAppearance=”?android:attr/textAppearanceMedium”/>
<Button
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Call”
android:id=”@+id/btn”/>
</LinearLayout>

MainActivity.java
package com.example.phoneCall.activities;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import com.example.phoneCall.R;
import android.widget.*;
import android.view.View.*;
import android.view.*;
import android.content.*;
import android.net.*;
import androidx.core.app.*;
import android.*;
import android.content.pm.*;

public class MainActivity extends AppCompatActivity {

EditText txt;
Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

txt=findViewById(R.id.txt);
btn=findViewById(R.id.btn);

btn.setOnClickListener(new View.OnClickListener(){

@Override
public void onClick(View view){

String string=txt.getText().toString();

if
(ActivityCompat.checkSelfPermission(getApplicationContext(),
Manifest.permission.CALL_PHONE)!=
PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(
MainActivity.this,new String[]{
Manifest.permission.CALL_PHONE},0);

} else {
   startActivity(new Intent(Intent.ACTION_CALL, Uri.parse(“tel:” + string)));
   }
}
});
}
    }