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<dependency> element (ClickOnce deployment)

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Identifies the version of the application to install, and the location of the application manifest.

Syntax


      <dependency>
   <dependentAssembly
      preRequisite
      visible
      dependencyType
      codeBase
      size
   >
      <assemblyIdentity
         name
         version
         publicKeyToken
         processorArchitecture
         language
         type
      />
      <hash>
         <dsig:Transforms>
            <dsig:Transform
                Algorithm
            />
         </dsig:Transforms>
         <dsig:DigestMethod />
         <dsig:DigestValue>
         </dsig:DigestValue>
      </hash>

   </dependentAssembly>
</dependency>

Elements and attributes

The dependency element is required. It has no attributes. A deployment manifest can have multiple dependency elements.

The dependency element usually expresses dependencies for the main application on assemblies contained within a ClickOnce application. If your Main.exe application consumes an assembly called DotNetAssembly.dll, then that assembly must be listed in a dependency section. Dependency, however, can also express other types of dependencies, such as dependencies on a specific version of the common language runtime, on an assembly in the global assembly cache (GAC), or on a COM object. Because it is a no-touch deployment technology, ClickOnce cannot initiate download and installation of these types of dependencies, but it does prevent the application from running if one or more of the specified dependencies do not exist.

dependentAssembly

Required. This element contains the assemblyIdentity element. The following table shows the attributes the dependentAssembly supports.

Attribute Description
preRequisite Optional. Specifies that this assembly should already exist in the GAC. Valid values are true and false. If true, and the specified assembly does not exist in the GAC, the application fails to run.
visible Optional. Identifies the top-level application identity, including its dependencies. Used internally by ClickOnce to manage application storage and activation.
dependencyType Required. The relationship between this dependency and the application. Valid values are:

- install. Component represents a separate installation from the current application.
- preRequisite. Component is required by the current application.
codebase Optional. The full path to the application manifest.
size Optional. The size of the application manifest, in bytes.

assemblyIdentity

Required. This element is a child of the dependentAssembly element. The content of assemblyIdentity must be the same as described in the ClickOnce application manifest. The following table shows the attributes of the assemblyIdentity element.

Attribute Description
Name Required. Identifies the name of the application.
Version Required. Specifies the version number of the application, in the following format: major.minor.build.revision
publicKeyToken Required. Specifies a 16-character hexadecimal string that represents the last 8 bytes of the SHA-1 hash of the public key under which the application or assembly is signed. The public key used to sign must be 2048 bits or greater.
processorArchitecture Required. Specifies the microprocessor. The valid values are x86 for 32-bit Windows and IA64 for 64-bit Windows.
Language Optional. Identifies the two part language codes of the assembly. For example, EN-US, which stands for English (U.S.). The default is neutral. This element is in the asmv2 namespace.
type Optional. For backwards compatibility with Windows side-by-side install technology. The only allowed value is win32.

hash

The hash element is an optional child of the file element. The hash element has no attributes.

ClickOnce uses an algorithmic hash of all the files in an application as a security check to ensure that none of the files were changed after deployment. If the hash element is not included, this check will not be performed. Therefore, omitting the hash element is not recommended.

dsig:Transforms

The dsig:Transforms element is a required child of the hash element. The dsig:Transforms element has no attributes.

dsig:Transform

The dsig:Transform element is a required child of the dsig:Transforms element. The following table shows the attributes of the dsig:Transform element.

Attribute Description
Algorithm The algorithm used to calculate the digest for this file. Currently the only value used by ClickOnce is urn:schemas-microsoft-com:HashTransforms.Identity.

dsig:DigestMethod

The dsig:DigestMethod element is a required child of the hash element. The following table shows the attributes of the dsig:DigestMethod element.

Attribute Description
Algorithm The algorithm used to calculate the digest for this file. Currently the only value used by ClickOnce is http://www.w3.org/2000/09/xmldsig#sha1.

dsig:DigestValue

The dsig:DigestValue element is a required child of the hash element. The dsig:DigestValue element has no attributes. Its text value is the computed hash for the specified file.

Remarks

Deployment manifests typically have a single assemblyIdentity element that identifies the name and version of the application manifest.

Example 1

The following code example shows a dependency element in a ClickOnce deployment manifest.

<!-- Identify the assembly dependencies -->
<dependency>
  <dependentAssembly dependencyType="install" allowDelayedBinding="true" codebase="MyApplication.exe" size="16384">
    <assemblyIdentity name="MyApplication" version="0.0.0.0" cultural="neutral" processorArchitecture="msil" />
    <hash>
      <dsig:Transforms>
        <dsig:Transform Algorithm="urn:schemas-microsoft-com:HashTransforms.Identity" />
      </dsig:Transforms>
      <dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
       <dsig:DigestValue>YzXYZJAvj9pgAG3y8jXUjC7AtHg=</dsig:DigestValue>
    </hash>
  </dependentAssembly>
</dependency>

Example 2

The following code example specifies a dependency on an assembly already installed in the GAC.

<dependency>
  <dependentAssembly dependencyType="preRequisite" allowDelayedBinding="true">
    <assemblyIdentity name="GACAssembly" version="1.0.0.0" language="neutral" processorArchitecture="msil" />
  </dependentAssembly>
</dependency>

Example 3

The following code example specifies a dependency on a specific version of the common language runtime.

<dependency>
  <dependentAssembly dependencyType="preRequisite" allowDelayedBinding="true">
    <assemblyIdentity name="Microsoft.Windows.CommonLanguageRuntime" version="2.0.50215.0" />
  </dependentAssembly>
</dependency>

Example 4

The following code example specifies an operating system dependency.

<dependency>
   <dependentOS supportUrl="http://www.microsoft.com" description="Microsoft Windows Operating System">
      <osVersionInfo>
         <os majorVersion="4" minorVersion="10" />
      </osVersionInfo>
   </dependentOS>
</dependency>

See also