android实现拨打电话

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
    <TextView
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/inputphonenumber"
    />
    <EditText
    android:id="@+id/phonenumber"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:phoneNumber="true"
    />
    <Button
    android:id="@+id/btn_call"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/call"
    />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.wide.phone"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />
    <!--添加可以向外拨打电话的权限  -->
    <uses-permission android:name="android.permission.CALL_PHONE"></uses-permission>
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".phoneAcitivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

package com.wide.phone;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class phoneAcitivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     
        Button btn_call = (Button) findViewById(R.id.btn_call);
        
        btn_call.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				// TODO Auto-generated method stub
				EditText et_phonenumber = (EditText)findViewById(R.id.phonenumber);
				String number = et_phonenumber.getText().toString();
				//用intent启动拨打电话
				Intent intent = new Intent(Intent.ACTION_CALL,Uri.parse("tel:"+number));
				startActivity(intent);
			}
		});
    }
}