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<fileAssociation> element (ClickOnce application)

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Applies to: yesVisual Studio noVisual Studio for Mac

Note

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Identifies a file extension to be associated with the application.

Syntax

<fileAssociation
    xmlns="urn:schemas-microsoft-com:clickonce.v1"
    extension
    description
    progid
    defaultIcon
/>

Elements and attributes

The fileAssociation element is optional. The element has the following attributes.

Attribute Description
extension Required. The file extension to be associated with the application.
description Required. A description of the file type for use by the shell.
progid Required. A name uniquely identifying the file type.
defaultIcon Required. Specifies the icon to use for files with this extension. The icon file must be specified by using the <file> Element within the <assembly> Element that contains this element.

Remarks

This element must include an XML namespace reference to "urn:schemas-microsoft-com:clickonce.v1". If the <fileAssociation> element is used, it must come after the <application> element in its parent <assembly> Element.

ClickOnce will not overwrite existing file associations. However, a ClickOnce application can override the file extension for the current user only. After that ClickOnce application is uninstalled, ClickOnce deletes the file association for the user, and the per-machine association is active again.

Example

The following code example illustrates fileAssociation elements in an application manifest for a text editor application deployed using ClickOnce. This code example also includes the <file> Element required by the defaultIcon attribute.

<file name="text.ico" size="4286">
  <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>0joAqhmfeBb93ZneZv/oTMP2brY=</dsig:DigestValue>
  </hash>
</file>
<file name="writing.ico" size="9662">
  <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>2cL2U7cm13nG40v9MQdxYKazIwI=</dsig:DigestValue>
  </hash>
</file>
<fileAssociation xmlns="urn:schemas-microsoft-com:clickonce.v1" extension=".text" description="Text  Document (ClickOnce)" progid="Text.Document" defaultIcon="text.ico" />
<fileAssociation xmlns="urn:schemas-microsoft-com:clickonce.v1" extension=".writing" description="Writings (ClickOnce)" progid="Writing.Document" defaultIcon="writing.ico" />

See also