Independent storage zone with Silverlight features-isolatedstorage

isolatedstorage is a special feature of Silverlight. It is a virtual file system of Silverlight. It is called a virtual file system, the official Microsoft documentation explains that the root of the Virtual File System is located in the fuzzy processing folder of each user on the physical file system. Each unique identifier provided by the host is mapped to a different root, this root provides its own Virtual File System for each application Program . An application cannot navigate from its own file system to another file system. That is to say, apart from some highly trusted Code and management tools that can be accessed from other assemblies, as well as unmanaged code that can be accessed, this space can only be accessed by this program, and thus it is highly secure. Windows Phone 7 is based on Silverlight, and its file system is also isolatedstorage. Its default size is 2 GB. Because of its security, it is not suitable for storing big data and important data, suitable for saving temporary data.

The namespace of isolatedstorage isSystem. Io. isolatedstorage, Which is included inIn the mscorlib assembly, there are four classes in the namespace:Isolatedstoragefile, isolatedstoragefilestream,Isolatedstorageexception,Isolatedstoragesettings, WhereIsolatedstoragefile and isolatedstoragefilestreamFor common use, the following is a simple example using these two classes.

To write and read files in isolatedstorage, first create a project and write the XAML code in mainpage. XAML:

 < Phone: phoneapplicationpage
  X: Class  = "Demo. mainpage"  
Xmlns  = "Http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
Xmlns: x  = "Http://schemas.microsoft.com/winfx/2006/xaml"  
Xmlns: Phone  = "CLR-namespace: Microsoft. Phone. controls; Assembly = Microsoft. Phone"  
Xmlns: Shell  = "CLR-namespace: Microsoft. Phone. Shell; Assembly = Microsoft. Phone"  
Xmlns: d = "Http://schemas.microsoft.com/expression/blend/2008"  
Xmlns: MC  = "Http://schemas.openxmlformats.org/markup-compatibility/2006"  
MC: ignorable  = "D"  D: designwidth  = "480"  D: designheight  = "696"  
Fontfamily  ="  {Staticresource phonefontfamilynormal}  "  
Fontsize ="  {Staticresource phonefontsizenormal}  "  
Foreground  ="  {Staticresource phoneforegroundbrush}  "  
Supportedorientations  = "Portraitorlandscape"  Orientation  = "Portrait"  
Shell: systemtray. isvisible  = "True"  >  

 <! --  Layoutroot is the root grid where all page content is placed  -->  
  <  Grid  X: Name  = "Layoutroot"  Background  = "Transparent"  >  
  <  Grid. rowdefinitions  >  
 <  Rowdefinition  Height  = "Auto"  />  
  <  Rowdefinition  Height  = "*"  />  
  </  Grid. rowdefinitions  >  

  <! -- Titlepanel contains the name of the application and page title  -->  
  <  Stackpanel  X: Name  = "Titlepanel"  Grid. Row  = "0"  Margin  ="  >  
  <  Textblock  X: Name = "Applicationtitle"  Text  = "My application"  Style  ="  {Staticresource phonetextnormalstyle}  "  />  
  <  Textblock  X: Name  = "Pagetitle"  Text  = "Page name"  Margin = "9,-7, 0, 0"  Style  ="  {Staticresource phonetexttitle1style}  "  />  
  </  Stackpanel  >  

  <! --  Contentpanel-place additional content here  -->  
  < Grid  X: Name  = "Contentpanel"  Grid. Row  = "1"  Margin  = "12, 0, 12, 0"  >  
  <  Button  Content  = "Writing Files"  Height  = "72"  Horizontalalignment  = "Left" Margin  = "9,148"  Name  = "Button2"  Verticalalignment  = "TOP"  Width  = "160"  Click  = "Button2_click"     />  
  <  Button  Content  = "Reading files" Height  = "72"  Horizontalalignment  = "Left"  Margin  = "205,148"  Name  = "Button3"  Verticalalignment  = "TOP"  Width  = "160"  Click  = "Button3_click"     /> 
  <  Textbox  Height  = "72"  Horizontalalignment  = "Left"  Margin  ="  Name  = "Textbox1"  Text  = ""  Verticalalignment  = "TOP"  Width = "460"     />  
  <  Textblock  Height  = "30"  Horizontalalignment  = "Left"  Margin  = "6,226"  Name  = "Textblock1"  Text  = ""  Verticalalignment = "TOP"     />  
  </  Grid  >  
  </  Grid  >  

  <! --  Sample Code showing usage of ApplicationBar  -->  
  <! -- <Phone: phoneapplicationpage. ApplicationBar>
<Shell: ApplicationBar isvisible = "true" ismenuenabled = "true">
<Shell: applicationbariconbutton iconuri = "/images/appbar_button1.png" text = "button 1"/>
<Shell: applicationbariconbutton iconuri = "/images/appbar_button2.png" text = "button 2"/>
<Shell: ApplicationBar. menuitems>
<Shell: applicationbarmenuitem text = "menuitem 1"/>
<Shell: applicationbarmenuitem text = "menuitem 2"/>
</Shell: ApplicationBar. menuitems>
</Shell: ApplicationBar>
</Phone: phoneapplicationpage. ApplicationBar>  -->  

  </  Phone: phoneapplicationpage > 

The mainpage class defines an independent storage object, which corresponds to a specific independent storage range and is initialized in the constructor.

 
Isolatedstoragefile ISF;
PublicMainpage ()
{
Initializecomponent ();
//Get application space, initialize
ISF=Isolatedstoragefile. getuserstoreforapplication ();
}
 

Last useIsolatedstoragefilestream class,Add events for the "Write File" and "Read File" buttons.

C # code:

    Private     Void  Button2_click (  Object  Sender, routedeventargs E)
{
 //  File write operations  
  Isolatedstoragefilestream filestream  =     New  Isolatedstoragefilestream (  "  Text.txt  "  , Filemode. Create, fileaccess. Write, ISF );
Streamwriter  =     New Streamwriter (filestream );
  If  (  This  . Textbox1.text  ! =     ""  )
{
Writer. writeline (  This  . Textbox1.text );
Writer. Close ();
}
  Else  
{
MessageBox. Show (  " The file to be written cannot be blank!  "  );
}
}

  Private     Void  Button3_click (  Object  Sender, routedeventargs E)
{
  //  File Read operations  
  Isolatedstoragefilestream filestream  =    New  Isolatedstoragefilestream (  "  Text.txt  "  , Filemode. Open, fileaccess. Read, ISF );
Streamreader  =     New  Streamreader (filestream );
  This  . Textblock1.text  =  Reader. readtoend ();
Reader. Close ();
} 

All right, a simple file can be written and read.