A key value of the string type. This value should not be changed from your code. It is updated automatically when the MediaData byte array is changed and is unique for each MediaDataObject. MediaDataKey is used in a URL of the MediaData loaded by a browser. The URL is generated under the following conditions.
MediaDataKey is constant while MediaData is not updated.
It is not required to load MediaData when generating the URL.
MediaDataKey can be quickly obtained as it is not required to load MediaData every time to calculate the key.
Currently, the MediaDataObject property type is completely supported by ASPxImagePropertyEditor only. The ImagePropertyEditor supports it partially - it uses MediaData only, and does not provide caching.
It is not recommend to change the MediaData value by direct database queries. In this instance, the URL will not change, and it will be required to manually refresh the page to see the changes.