Android app with eclipse and php mysql(wamp server)

How I developed my Android App on Eclipse using PHP-MySQL database (running wamp server)

My working Environment      :

            Front End      : ECLIPSE

            Back End       : PHP-MySQL

            Server used    : Wamp Server

App Development Modules    :

· Creating Activity Layouts

· Adding widgets and other interfacing elements(textboxes, edit texts and whatever )

· Creating button onclick events

· Connecting these layouts(or simply pages :p) using intents

·         Database connectivity

ü  Working with wamp

ü  The php-mysql side

Errors that I fought with in each module :

Creating Activity Layouts:

Ø  Right click on your project

Ø  Click on new

Ø  Click on other

Ø  Then Android activityàBlank Activityà Give a name to your activity starting with a capital letteràclick finish and you are done!!

 

 Problem  1       :  

 While using downloaded layouts from external sources in our project, we usually come across the weird “unfortunately the app has stopped ”  stuff and the subsequent app crash.

Solution            :    

A general solution to this problem is adding an activity tag for the downloaded layouts in our android manifest file.

Example           :

<activity android:name="packagename.Addemp" />

Here “Addemp” is the java class name for the layout and “packagename” is the name of the package listed under the “src” folder in your app. Just add this inside your <application></application > tag

Problem 2        :    

While creating the layout xml file and the java file separatelyfor creating an activity rather than creating a new activity (which creates both the java and xml file and connects it), we will 

have to manually configure the java file to connect both.

Solution            :     

this can be solved by adding the name of the layout xml file correctly in the setContentView of java file

Example           :    

The layout file addemployee.xml file can be connected to the java file by updating the setContentView of java file as setContentView(R.layout.addemployee);

Problem 3        :   

While working with projects that is associated with internet, contact access, gps, wifi state, write to SD card etc, we might  get permission errors.

Solution            :     

These errors can be avoided by adding a permission setting in android manifest file.

Example           :     

The permission setting for internet access is

<uses-permission android:name="android.permission.INTERNET" >

</uses-permission>

Creating buttons and setting setOnClickListener

Ø Once you have created your android activity as mentioned before, drag and drop a button into your layout xml file

Ø Double click on your button and note down(jst keep in mind :p) your button id.

Ø Now go to your java file associated with this android activity and declare a new button(let it be Button b1; )

Ø Now attach this button b1 to the button id earlier created in the layout file like this

b1=(Button)findViewById(R.id.button1);

Assuming the button id as button1.

Ø Now to make the button to perform some task when clicked, type

b2.setOnClickListener(new OnClickListener() {

                    

                     @Override

                     public void onClick(View arg0) {

                           // TODO Auto-generated method stub

                          

                     }

          }); 

Don’t copy paste the code as it may treat you with a bunch of errors!! So just type it, and the auto complete feature will help you 

Ø Anything you would like the button to perform can be specified within the  

method as,

              onClick(View arg0)

b1.setOnClickListener(new OnClickListener() {

                    

                     @Override

                     public void onClick(View arg0) {

                           // TODO Auto-generated method stub

                           startActivity (new Intent (MainActivity.this, Addemp.class));

                     }

});

This method is used to move from one android activity to another on a button click. Usage of “intent” to move from one activity to another is described in the coming sections.

Problem 1            : 

The OnClickListener inside the setOnClickListener is highlighted in    red. 

Solution               : 

clicking the error button it says import OnClickListener, tap that to  perform the import and if that too don’t work remove the import and tap ctrl+shift+O and hopefully this should fix it.

Handling “Intents”

As mentioned before intents can be created as

startActivity (new Intent (MainActivity.this, Addemp.class));

where MainActivity is the current class(java file of current android activity) and Addemp.class is the java class of android activity which should be displayed on button click. 

Database Implementation 

Back End    : PHP-MySQL        Server used : Wamp Server 

In order to start implementing database connectivity in your project, assuming you are beginners, it is always recommended(I recommend!! :p) to start developing on an already implemented project available for download on the internet. If you get the android source files, php files and mysql table details, it is always easy to get started and finally editing down the contents to suit your project. By going this way you can get an absolute knowledge about the project implementation. Trust me, I too have learned this way. 

By the way I have developed a project by editing one  I downloaded from somewhere, which is available for download below. You may download the project and edit yourselves to build your project. 

App android eclipse files

App mysql database files

App php files 

In order to successfully run your project, follow the steps below     : 

Ø Download and install wamp server 

Ø Open wamp server by typing localhost in the default web browser and import the downloaded database. 

Ø Now close wamp(ensure it runs in background by seeing the wamp icon on taskbar. 

Ø Now go to C:\wamp\www and paste the downloaded php files 

Ø Now open up eclipse and import the android files(import option can be found in fileàimport) 

Ø Now run your android project in eclipse and you are done

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