Question: I am new to Iphone.How to create file browser in iphone ?
I wish to show all the files and folders in the iphone.How to do this?

Answer: 
Unless you are on a jailbroken phone, your app can only access files within its own "sandbox". 

There are [three folders](http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/RuntimeEnvironment/RuntimeEnvironment.html#//apple_ref/doc/uid/TP40007072-CH2-SW12) your app can access, which contain data specific to your application. Your app will not be able to access file data outside these folders.

With that caveat in mind, you would likely use:

1. [`NSFileManager`](http://developer.apple.com/library/ios/#documentation/cocoa/reference/foundation/Classes/NSFileManager_Class/Reference/Reference.html) and [`NSDirectoryEnumerator`](http://developer.apple.com/library/ios/#documentation/Cocoa/Reference/Foundation/Classes/NSDirectoryEnumerator_Class/Reference/Reference.html) to build a data source to a table view
2. [`UITableView`](http://developer.apple.com/library/ios/#documentation/uikit/reference/UITableView_Class/Reference/Reference.html) to present the list of files and folders obtained from step 1
3. [`UINavigationController`](http://developer.apple.com/library/ios/#documentation/uikit/reference/UINavigationController_Class/Reference/Reference.html) to provide a navigation stack for walking through a hierarchy of folders: a stack of `UITableView` instances

to browse the list of accessible files and folders within your application's sandbox.
If you are producing this for the App Store, I would suggest against exposing such a control even for your application's data. It violates the Human Interface Guidelines and most likely will be rejected.

From the [iPad Human Interface Guidelines](http://developer.apple.com/library/ios/#documentation/general/conceptual/ipadhig/DesignGuidelines/DesignGuidelines.html%23//apple_ref/doc/uid/TP40009446-CH3-SW32):

> 
> Although iPad applications can allow
>  people to create and manipulate files,
>  this does not mean that people should
>  have a sense of the file system on
>  iPad.
> 
> 
> On iPad, there is no application
>  analogous to the Mac OS X Finder, and
>  people should not be asked to interact
>  with files as they do on a computer.
>  In particular, people should not be
>  faced with anything that encourages
>  them to think about file types or
>  locations, such as:
> 
> 
> * An open or save dialog that exposes a file hierarchy
> * Information about the permissions status of files
> 
> 
>