Easy Android Dialer

One, video notes:

1.

When the user clicks the app icon--

First create an app process--

Then create a main thread--

The main thread instantiates activity "NOTE: The OS will store information about the application (Context) into activity"--

Call OnCreate () "NOTE: An OS call, not a user call, is called only once during a life cycle"

2. Use of units

Text: SP

Non-text: DP (=DIP)

3.

When developing software, the content of the interface (. xml) is first written in a project.

Second, the Practice:

1. Interface:

The final layout to implement:

In Activity_main.xml:

1 <LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"2 android:orientation= "vertical"3 Android:layout_width= "Match_parent"4 Android:layout_height= "Match_parent" >5 6     <TextView7         Android:layout_width= "Match_parent"8 Android:layout_height= "Wrap_content"9 Android:text= "@string/mobile" />Ten      One     <EditText A         Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" - Android:id= "@+id/mobile" the         /> -      -     <Button -         Android:layout_width= "Wrap_content" + Android:layout_height= "Wrap_content" - Android:text= "@string/button"  + Android:id= "@+id/button" A         /> at  - </LinearLayout>

String.xml (For more internationalization):

<?XML version= "1.0" encoding= "Utf-8"?><Resources>    <stringname= "App_name">Phone Dialer</string>    <stringname= "Hello_world">Hello world!</string>    <stringname= "Action_settings">Settings</string>    <stringname= "mobile">Please enter your phone number</string>    <stringname= "button">Dial</string></Resources>

2. Request permission in the manifest file:

<?XML version= "1.0" encoding= "Utf-8"?><Manifestxmlns:android= "Http://schemas.android.com/apk/res/android" Package= "Com.example.phone"Android:versioncode= "1"Android:versionname= "1.0" >    <USES-SDKandroid:minsdkversion= "+"android:targetsdkversion= "+" />    <ApplicationAndroid:allowbackup= "true"Android:icon= "@drawable/ic_launcher"Android:label= "@string/app_name"Android:theme= "@style/apptheme" >        <ActivityAndroid:name=". Mainactivity "Android:label= "@string/app_name" >            <Intent-filter>                <ActionAndroid:name= "Android.intent.action.MAIN" />                <categoryAndroid:name= "Android.intent.category.LAUNCHER" />            </Intent-filter>        </Activity>    </Application><!--permissions: Google to protect the user's information security and privacy data, when using the relevant data, must request the relevant permissions, the software installation will appear the permission prompt -    <uses-permission  android:name= "Android.permission.CALL_PHONE"/ > </Manifest>

3. Code implementation:

Mainactivity.java:

 PackageCom.example.phone;Importandroid.app.Activity;Importandroid.content.Intent;ImportAndroid.net.Uri;ImportAndroid.os.Bundle;ImportAndroid.view.Menu;ImportAndroid.view.MenuItem;ImportAndroid.view.View;ImportAndroid.widget.Button;ImportAndroid.widget.EditText; Public classMainactivityextendsActivity {PrivateEditText Mobiletext; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);                Setcontentview (R.layout.activity_main); Mobiletext=(EditText) Findviewbyid (r.id.mobile); Button Button= (Button) This. Findviewbyid (R.id.button); Button.setonclicklistener (NewButtonclicklistener ());//or use an anonymous inner class: New implements the interface's class object    }    //Internal classes: Heavy use, submission of software loading (to virtual machine) speed    Private Final classButtonclicklistenerImplementsView.onclicklistener {@Override Public voidOnClick (View v) {//the input parameter is the button object that is currently clicked//TODO auto-generated Method Stub//each time you click on the dial, the following sentence will use Findviewbyid to find the resource ID, resulting in time-consuming//EditText mobiletext = (EditText) Findviewbyid (r.id.mobile);String number =Mobiletext.gettext (). toString (); Intent Intent = new  Intent (); Intent.setaction ("Android.intent.action.CALL"); // intent.addcategory ("Android.intent.category.DEFAULT"); //            1 Code intent.setdata (Uri.parse ("Tel:" + number);  // The intent is passed to the OS, the OS discovers matching activity, activates startactivity (intent); // Note: Android.intent.category.DEFAULT is automatically added to the intent method internally, so the 1 code comment does not         }            }}

Easy Android Dialer