问如何从android应用程序拨打电话

EN

import android.app.*;
import android.os.*;
import android.view.*;
import android.widget.*;
import android.content.Intent;
import android.content.*;
import android.net.Uri;
import android.view.View.OnClickListener;


public class MainActivity extends Activity
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button = (Button) findViewById(R.id.youButtonId);
        Button button1 = (Button) findViewById(R.id.youButtonId1);
        // add button listener
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                phoneCall();
            }
        });
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                phoneCall1();
            }
        });
    }
    private void phoneCall()
    {
        String phoneCallUri = "tel:8889807091";
        Intent phoneCallIntent = new Intent(Intent.ACTION_CALL);
        phoneCallIntent.setData(Uri.parse(phoneCallUri));
        startActivity(phoneCallIntent);
    }
    private void phoneCall1()
    {
        String phoneCallUri = "tel:4078421430";
        Intent phoneCallIntent = new Intent(Intent.ACTION_CALL);
        phoneCallIntent.setData(Uri.parse(phoneCallUri));
        startActivity(phoneCallIntent);
    }
}