EnvironmentPolicy Class

Allows you to spot, analyze, and prohibit unwanted requests to System.Environment initiated by DevExpress controls.

Namespace: DevExpress.Data.Utils

Assembly: DevExpress.Data.v24.2.dll

Declaration

C#

public static class EnvironmentPolicy

VB.NET

Public Module EnvironmentPolicy

Remarks

DevExpress UI controls can access (read and write) information about the environment in which an application is running. The EnvironmentPolicy allows you to apply global environment access restrictions, or track app initiated requests and execute custom actions in response.

Use the following methods at application startup to apply a restrictive policy:

• SuppressAll() – Suppresses all requests to System.Environment. No exception is thrown.
• SuppressSettingEnvironmentVariables() – Disallows setting environment variables.
• SuppressGettingEnvironmentVariables() – Disallows reading environment variables.
• SuppressReadingCurrentProcessData() – Disallows reading current process data (for example, CurrentDirectory, ProcessId, ProcessPath).
• SuppressExitProcess() – Disallows DevExpress controls to forcibly exit the current process.
• SuppressSettingCurrentDirectory() – Disallows setting the current directory.
• SuppressReadingSpecialFolder(Environment.SpecialFolder) – Disallows getting the path to the specified system special folder.

The following example suppresses all requests to System.Environment initiated by DevExpress controls:

C#

using System;
using System.Windows.Forms;

namespace EnvironmentPolicyDemo {
    internal static class Program {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            DevExpress.Data.Utils.EnvironmentPolicy.SuppressAll();
            Application.Run(new Form1());
        }
    }
}

VB.NET

Imports System
Imports System.Windows.Forms

Namespace EnvironmentPolicyDemo
    Friend Module Program
        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        <STAThread>
        Sub Main()
            Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            DevExpress.Data.Utils.EnvironmentPolicy.SuppressAll()
            Application.Run(New Form1())
        End Sub
    End Module
End Namespace

Use the following methods to trace and handle exceptions:

• ThrowAlways() – Throws an exception when the DevExpress control accesses System.Environment.
• ThrowOnErrors() – Throws an exception if a request to System.Environment fails.

Handle the Failed event to respond to associated failures.

C#

using System;
using System.Windows.Forms;

namespace EnvironmentPolicyDemo {
    internal static class Program {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            DevExpress.Data.Utils.EnvironmentPolicy.ThrowOnErrors();
            DevExpress.Data.Utils.EnvironmentPolicy.Failed += EnvironmentPolicy_Failed;
            Application.Run(new Form1());
        }

        static void EnvironmentPolicy_Failed(object sender, DevExpress.Data.Utils.EnvironmentPolicy.FailedEventArgs e) {
            Console.WriteLine(e.Exception.Message);
            e.Throw = false;
        }
    }
}

VB.NET

Imports System
Imports System.Windows.Forms

Namespace EnvironmentPolicyDemo
    Friend Module Program
        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        <STAThread>
        Sub Main()
            Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            DevExpress.Data.Utils.EnvironmentPolicy.ThrowOnErrors()
            AddHandler DevExpress.Data.Utils.EnvironmentPolicy.Failed, AddressOf EnvironmentPolicy_Failed
            Application.Run(New Form1())
        End Sub

        Private Sub EnvironmentPolicy_Failed(ByVal sender As Object, ByVal e As DevExpress.Data.Utils.EnvironmentPolicy.FailedEventArgs)
            Console.WriteLine(e.Exception.Message)
            e.Throw = False
        End Sub
    End Module
End Namespace

Handle the following events to allow or cancel environment-related operations based on a specific condition:

• ExitingProcess
• ExpandingVariables
• GettingVariable
• SettingVariable
• ReadingCurrentProcessData
• ReadingSpecialFolder
• SettingCurrentDirectory

Tip

Read the following topic for additional information: Environment Policy.

Inheritance

Object

EnvironmentPolicy