Android Application Development-call the system call function demo

I. Interface Design (not designed at all)

An editview and a button are displayed on the right:

<RelativeLayout 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"    tools:context=".MainActivity" >    <EditText        android:id="@+id/phoneNo"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_centerHorizontal="true"        android:layout_marginTop="49dp"        android:ems="10" />    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/mobile"        android:layout_alignRight="@+id/mobile"        android:layout_below="@+id/mobile"        android:layout_marginTop="50dp"        android:text="call" /></RelativeLayout>

Ii. Code Implementation

Mainactivity. Java

Button. setonclicklistener (new view. onclicklistener () {@ overridepublic void onclick (view v) {// todo auto-generated method stubphonetext = (edittext) findviewbyid (R. id. phoneno); string phoneno = phonetext. gettext (). tostring (); If (phoneno = NULL | "". equals (phoneno. trim () {toast. maketext (getapplicationcontext (), "no phone number", toast. length_short ). show ();} else {toast. maketext (getapplicationcontext (), "with phone number" + phoneno, toast. length_short ). show (); intent = new intent (intent. action_call, Uri. parse ("Tel:" + phoneno); startactivity (intent );}}});