在清單文件中需要用到權限：

 <uses-permission android:name="android.permission.CALL_PHONE"/>

獲取到輸入的號碼後需要用intent 啟動撥號器：

Intent intent=new Intent(Intent.ACTION_CALL,Uri.parse(("tel:"+infos)));
 startActivity(intent);

以下全部代碼：

package com.example.callphone;

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 MainActivity extends Activity {

	private EditText my_info;
	private Button my_call;

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

		init();
	}

	private void init() {
		// TODO Auto-generated method stub
		my_call = (Button) findViewById(R.id.call);
		my_info = (EditText) findViewById(R.id.info);

		my_call.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub

				String infos = my_info.getText().toString().trim();

				Intent intent = new Intent(Intent.ACTION_CALL, Uri
						.parse(("tel:" + infos)));
				startActivity(intent);
			}
		});
	}

}

xml布局代碼：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.callphone.MainActivity" >

    <EditText
        android:id="@+id/info"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="請輸入號碼" />
    <Button
        android:id="@+id/call"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="撥打" />
</LinearLayout>

Android 撥號器