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CorBindToRuntimeEx Function

Enables unmanaged hosts to load the common language runtime (CLR) into a process. The CorBindToRuntime Function and CorBindToRuntimeEx functions perform the same operation, but the CorBindToRuntimeEx function allows you to set flags to specify the behavior of the CLR.

See Hosting the Common Language Runtime for a complete description of the scenarios in which CorBindToRuntimeEx is used.

This function takes a set of parameters that allow a host to do the following:

  • Specify the version of the runtime that will be loaded.

  • Indicate whether the server or workstation build should be loaded.

  • Control whether concurrent garbage collection or non-concurrent garbage collection is done.

  • Control whether assemblies are loaded as domain-neutral.

  • Obtain an interface pointer to an ICorRuntimeHost Interface that can be used to set additional options for configuring an instance of the CLR before it is started.

HRESULT CorBindToRuntimeEx (
        [in]  LPWSTR    pwszVersion, 
        [in]  LPWSTR    pwszBuildFlavor, 
        [in]  DWORD     flags, 
        [in]  REFCLSID  rclsid, 
        [in]  REFIID    riid, 
        [out] LPVOID*   ppv


  • pwszVersion
    [in] A string describing the version of the CLR you want to load.

    A version number in the .NET Framework consists of four parts separated by periods: The string passed as pwszVersion must start with the character "v" followed by the first three parts of the version number (for example, "v1.0.1529").

    Some versions of the CLR are installed with a policy statement that specifies compatibility with previous versions of the CLR. By default, the startup shim evaluates pwszVersion against policy statements and loads the latest version of the runtime that is compatible with the version being requested. A host can force the shim to skip policy evaluation and load the exact version specified in pwszVersion by passing a value of STARTUP_LOADER_SAFEMODE for the flags parameter, as described below.

    If the caller specifies null for pwszVersion, the latest version of the runtime is loaded. Passing null gives the host no control over which version of the runtime is loaded. Although this approach may be appropriate in some scenarios, it is strongly recommended that the host supply a specific version to load.

  • pwszBuildFlavor
    [in] A string that specifies whether to load the server or the workstation build of the CLR. Valid values are svr and wks. The server build is optimized to take advantage of multiple processors for garbage collections, and the workstation build is optimized for client applications running on a single-processor machine.

    If pwszBuildFlavor ** is set to null, the workstation build is loaded. When running on a single-processor machine, the workstation build is always loaded, even if pwszBuildFlavor ** is set to svr. However, if pwszBuildFlavor ** is set to svr and concurrent garbage collection is specified (see the description of the flags parameter), the server build is loaded.

  • flags
    [in] A combination of values of the STARTUP_FLAGS Enumeration enumeration. These flags control concurrent garbage collection, domain-neutral code, and the behavior of the pwszVersion parameter. The default is single domain if no flag is set. The following values are valid:














    For descriptions of these flags, see the STARTUP_FLAGS Enumeration enumeration.

  • rclsid
    [in] The CLSID of the coclass that implements the ICorRuntimeHost Interface interface. Supported values are CLSID_CorRuntimeHost or CLSID_CLRRuntimeHost.
  • riid
    [in] The IID of the requested interface from rclsid. Supported values are IID_ICorRuntimeHost or IID_ICLRRuntimeHost.
  • ppv
    [out] The returned interface pointer to riid.


If pwszVersion specifies a runtime version that does not exist, CorBindToRuntimeEx returns an HRESULT value of CLR_E_SHIM_RUNTIMELOAD.

Execution Context and Flow of Windows Identity

In version 1 of the CLR, the WindowsIdentity object does not flow across asynchronous points such as new threads, thread pools, or timer callbacks. In version 2.0 of the CLR, an ExecutionContext object wraps some information about the currently executing thread and flows it across any asynchronous point, but not across application domain boundaries. Similarly, the WindowsIdentity object also flows across any asynchronous point. Therefore, the current impersonation on the thread, if any, flows too.

You can alter the flow in two ways:

  1. By modifying the ExecutionContext settings to suppress the flow on a per-thread basis (see the SuppressFlow, SuppressFlow, and SuppressFlowWindowsIdentity methods).

  2. By changing the process default mode to the version 1 compatibility mode, where the WindowsIdentity object does not flow across any asynchronous point, regardless of the ExecutionContext settings on the current thread. How you change the default mode depends on whether you use a managed executable or an unmanaged hosting interface to load the CLR:

    1. For managed executables, you must set the enabled attribute of the <legacyImpersonationPolicy> Element to true.

    2. For unmanaged hosting interfaces, set the STARTUP_LEGACY_IMPERSONATION flag in the flags parameter when calling the CorBindToRuntimeEx function.

    The version 1 compatibility mode applies to the entire process and to all the application domains in the process.


Platforms: Windows 2000, Windows XP, Windows Server 2003 family

Header: MSCorEE.idl

Library: MSCorEE.dll

.NET Framework Version: 2.0, 1.1, 1.0

See Also


CorBindToCurrentRuntime Function
CorBindToRuntime Function
CorBindToRuntimeByCfg Function
CorBindToRuntimeHost Function
ICorRuntimeHost Interface

Other Resources

Hosting Global Static Functions