WebConfigurationManager.OpenMappedWebConfiguration Method (WebConfigurationFileMap, String)

 

Opens the specified Web-application configuration file as a Configuration object using the specified file mapping and virtual path to allow read or write operations.

Namespace:   System.Web.Configuration
Assembly:  System.Web (in System.Web.dll)

public static Configuration OpenMappedWebConfiguration(
	WebConfigurationFileMap fileMap,
	string path
)

Parameters

fileMap
Type: System.Web.Configuration.WebConfigurationFileMap

The WebConfigurationFileMap object to use in place of a default Web-application configuration file.

path
Type: System.String

The virtual path to the configuration file.

Exception Condition
ConfigurationErrorsException

A valid configuration file could not be loaded.

To obtain the Configuration object for a resource, your code must have read privileges on all the configuration files from which it inherits settings. To update a configuration file, your code must additionally have write privileges for both the configuration file and the directory in which it exists.

The following example shows how to use the OpenMappedWebConfiguration method.


// Show how to use the OpenMappedWebConfiguration(
// WebConfigurationFileMap, string)
static void OpenMappedWebConfiguration1()
{

    // Create the configuration directories mapping.
    WebConfigurationFileMap fileMap = 
        CreateFileMap();

    try
    {

        // Get the Configuration object for the mapped
        // virtual directory.
        System.Configuration.Configuration config =
            WebConfigurationManager.OpenMappedWebConfiguration(fileMap, 
            "/config");

        // Define a nique key for the creation of 
        // an appSettings element entry.
        int appStgCnt = config.AppSettings.Settings.Count;
        string asName = "AppSetting" + appStgCnt.ToString();

        // Add a new element to the appSettings.
        config.AppSettings.Settings.Add(asName,
            DateTime.Now.ToLongDateString() + " " +
            DateTime.Now.ToLongTimeString());

        // Save to the configuration file.
        config.Save(ConfigurationSaveMode.Modified);

        // Display new appSettings.
        Console.WriteLine("Count:  [{0}]", config.AppSettings.Settings.Count);
        foreach (string key in config.AppSettings.Settings.AllKeys)
        { 
            Console.WriteLine("[{0}] = [{1}]", key, 
                config.AppSettings.Settings[key].Value);
        }

    }
    catch (InvalidOperationException err)
    {
        Console.WriteLine(err.ToString());
    }

    Console.WriteLine();
}

The preceding example uses the following custom method to generate a ConfigurationFileMap object.


        // Utility to map virtual directories to physical ones.
        // In the current physical directory maps 
        // a physical sub-directory with its virtual directory.
        // A web.config file is created for the
        // default and the virtual directory at the appropriate level.
        // You must create a physical directory called config at the
        // level where your app is running.
        static WebConfigurationFileMap CreateFileMap()
        {

            WebConfigurationFileMap fileMap =
                   new WebConfigurationFileMap();

            // Get he physical directory where this app runs.
            // We'll use it to map the virtual directories
            // defined next. 
            string physDir = Environment.CurrentDirectory;

            // Create a VirtualDirectoryMapping object to use
            // as the root directory for the virtual directory
            // named config. 
            // Note: you must assure that you have a physical subdirectory
            // named config in the curremt physical directory where this
            // application runs.
            VirtualDirectoryMapping vDirMap = 
                new VirtualDirectoryMapping(physDir + "\\config", true);

            // Add vDirMap to the VirtualDirectories collection 
            // assigning to it the virtual directory name.
            fileMap.VirtualDirectories.Add("/config", vDirMap);

            // Create a VirtualDirectoryMapping object to use
            // as the default directory for all the virtual 
            // directories.
            VirtualDirectoryMapping vDirMapBase =
                new VirtualDirectoryMapping(physDir, true, "web.config");

            // Add it to the virtual directory mapping collection.
            fileMap.VirtualDirectories.Add("/", vDirMapBase);

# if DEBUG  
            // Test at debug time.
            foreach (string key in fileMap.VirtualDirectories.AllKeys)
            {
                Console.WriteLine("Virtual directory: {0} Physical path: {1}",
                fileMap.VirtualDirectories[key].VirtualDirectory, 
                fileMap.VirtualDirectories[key].PhysicalDirectory);
            }
# endif 

            // Return the mapping.
            return fileMap;

        }

Refer to OpenMachineConfiguration for an example that shows how to map a virtual directory hierarchy to a physical one.

.NET Framework
Available since 2.0
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