Sample: Image Operations using Dataverse Web API

Article
01/12/2023

This .NET 6.0 sample demonstrates how to perform operations with image columns using the Dataverse Web API.

This sample uses the common helper code in the WebAPIService class library (C#).

Prerequisites

Microsoft Visual Studio 2022
Access to Dataverse with system administrator or system customizer privileges.

How to run the sample

Clone or download the PowerApps-Samples repository.
Open the PowerApps-Samples\dataverse\webapi\C#-NETx\ImageOperations\ImageOperations.sln file using Visual Studio 2022.

Edit the appsettings.json file to set the following property values:

Property	Instructions
`Url`	The Url for your environment. Replace the placeholder `https://yourorg.api.crm.dynamics.com` value with the value for your environment. See View developer resources to find this.
`UserPrincipalName`	Replace the placeholder `you@yourorg.onmicrosoft.com` value with the UPN value you use to access the environment.
`Password`	Replace the placeholder `yourPassword` value with the password you use.

Save the appsettings.json file
Press F5 to run the sample.

Sample Output

The output of the sample should look something like this:

Creating image column named 'sample_ImageColumn' on the account table ...
Created image column named 'sample_ImageColumn' in the account table.
Create 5 records while CanStoreFullImage is false.
        Created account: 'CanStoreFullImage false 144x144.png'
        Created account: 'CanStoreFullImage false 144x400.png'
        Created account: 'CanStoreFullImage false 400x144.png'
        Created account: 'CanStoreFullImage false 400x500.png'
        Created account: 'CanStoreFullImage false 60x80.png'
Set the CanStoreFullImage property to True
Create 5 records while CanStoreFullImage is true.
        Created account: 'CanStoreFullImage true 144x144.png'
        Created account: 'CanStoreFullImage true 144x400.png'
        Created account: 'CanStoreFullImage true 400x144.png'
        Created account: 'CanStoreFullImage true 400x500.png'
        Created account: 'CanStoreFullImage true 60x80.png'
Retrieving records with thumbnail images:
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage false 144x144.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage false 144x400.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage false 400x144.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage false 400x500.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage false 60x80.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage true 144x144.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage true 144x400.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage true 400x144.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage true 400x500.png_retrieved.png
        Thumbnail-sized file column data saved to DownloadedImages\CanStoreFullImage true 60x80.png_retrieved.png
Attempt to download full-size images for all 10 records using 3 different methods:
Download full-sized files with actions: 5 should fail
        Download failed: No FileAttachment records found for imagedescriptorId: e40bdcf1-598d-ed11-81ad-000d3a9933c9 for image attribute: sample_imagecolumn of account record with id e30bdcf1-598d-ed11-81ad-000d3a9933c9
        Download failed: No FileAttachment records found for imagedescriptorId: 2258d4f7-598d-ed11-81ad-000d3a9933c9 for image attribute: sample_imagecolumn of account record with id 2158d4f7-598d-ed11-81ad-000d3a9933c9
        Download failed: No FileAttachment records found for imagedescriptorId: 2658d4f7-598d-ed11-81ad-000d3a9933c9 for image attribute: sample_imagecolumn of account record with id 2558d4f7-598d-ed11-81ad-000d3a9933c9
        Download failed: No FileAttachment records found for imagedescriptorId: 2a58d4f7-598d-ed11-81ad-000d3a9933c9 for image attribute: sample_imagecolumn of account record with id 2958d4f7-598d-ed11-81ad-000d3a9933c9
        Download failed: No FileAttachment records found for imagedescriptorId: 2e58d4f7-598d-ed11-81ad-000d3a9933c9 for image attribute: sample_imagecolumn of account record with id 2d58d4f7-598d-ed11-81ad-000d3a9933c9
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x144.png_downloaded_with_actions.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x400.png_downloaded_with_actions.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x144.png_downloaded_with_actions.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x500.png_downloaded_with_actions.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 60x80.png_downloaded_with_actions.png
Download full-sized files with chunks: 5 should fail
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x144.png_downloaded_with_chunks_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x400.png_downloaded_with_chunks_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x144.png_downloaded_with_chunks_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x500.png_downloaded_with_chunks_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 60x80.png_downloaded_with_chunks_full-sized.png
Download full-sized files in single requests: 5 should fail
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        No full-sized image data returned because record was created while CanStoreFullImage was false.
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x144.png_downloaded_with_stream_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 144x400.png_downloaded_with_stream_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x144.png_downloaded_with_stream_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 400x500.png_downloaded_with_stream_full-sized.png
        Full-sized file downloaded to DownloadedImages\CanStoreFullImage true 60x80.png_downloaded_with_stream_full-sized.png
Deleting the image data from the columns using 3 different methods:
        CanStoreFullImage false 144x144.png sample_imagecolumn deleted with PATCH
        CanStoreFullImage false 144x400.png sample_imagecolumn deleted with PATCH
        CanStoreFullImage false 400x144.png sample_imagecolumn deleted with PATCH
        CanStoreFullImage false 400x500.png sample_imagecolumn deleted with PUT
        CanStoreFullImage false 60x80.png sample_imagecolumn deleted with PUT
        CanStoreFullImage true 144x144.png sample_imagecolumn deleted with PUT
        CanStoreFullImage true 144x400.png sample_imagecolumn deleted with DELETE
        CanStoreFullImage true 400x144.png sample_imagecolumn deleted with DELETE
        CanStoreFullImage true 400x500.png sample_imagecolumn deleted with DELETE
        CanStoreFullImage true 60x80.png sample_imagecolumn deleted with DELETE
Deleted the account records created for this sample.
Deleting the image column named 'sample_ImageColumn' on the account table ...
Deleted the image column named 'sample_ImageColumn' in the account table.
Sample completed.

Demonstrates

The code for this sample is in the Program.cs file.

The project uses a Utility class to perform operations involving creating or retrieving schema data. This class is in the Utility.cs file.

This project performs these operations:

Create an image column

This sample needs to create a new image column that is the primary image for the account table. It must also return the system to the original state when it's finished. So the program does these things at the beginning:

Capture the original primary image name using the Utility.GetTablePrimaryImageName method.
Use the Utility.CreateImageColumn method to create a new image column named sample_ImageColumn on the account table if it doesn't exist already.

Note

This image column CanStoreFullImage value is false.
Use the Utility.SetTablePrimaryImageName method to make the new sample_ImageColumn the primary image column.

Create account records with image data

The program loops through a list of five filenames that match the names of files in the Images folder.
For each image, the program creates an account record with the name set to CanStoreFullImage false {fileName} and the file byte[] is set as the sample_ImageColumn value.
The program then uses the Utility.UpdateCanStoreFullImage method to set the sample_ImageColumn column definition CanStoreFullImage value to true.
Again, the program loops through the file names and creates five account records with the same image files set to the sample_ImageColumn value. This time the name is CanStoreFullImage true {fileName}

In the following code, we can see how the value of the CanStoreFullImage property changes what data is available.

Retrieve the account records

The code retrieves the 10 account records created in the previous step, including the image data.
For each account record, the image data is downloaded to the DownloadedImages folder with the name {recordName}_retrieved.png.

Note

All of these records are thumbnail-sized images.

Download the account record images

This program uses three different methods to download image files.

Note

In each case, 5 of the 10 operations will fail because no full-sized images were uploaded while CanStoreFullImage was false. Those records created while CanStoreFullImage was true succeed.

Download with Actions

The code uses the static DownloadImageWithActions method, which encapsulates the use of the InitializeFileBlocksDownload and DownloadBlock actions to download the images as described in Use Dataverse messages to download a file.

Note

These operations fail when there's no full-sized image to download. The error message is: No FileAttachment records found for imagedescriptorId: <guid> for image attribute: sample_imagecolumn of account record with id <guid>.

Download with Chunks

The code uses the static DownloadImageWithChunks method, which demonstrates how to download images as described in Download the file in chunks using Web API.

Note

These operations don't fail when there's no full-sized image to download, they simply return 204 No Content.

Download with Stream

The code uses the static DownloadImageWithStream method, which demonstrates how to download images as described in Download a file in a single request using Web API

Note

These operations don't fail when there's no full-sized image to download, they simply return 204 No Content.

Delete the image data

The program uses three different methods to demonstrate deleting image values, using PATCH, PUT, and DELETE.
The program verifies the records are deleted by retrieving the records again using the same criteria as before. The value for the image column is null.

Clean up

To leave the system in the state before the sample ran, the program does the following:

Delete the account records.
Set the account table primary image back to the original value.
Delete the image column.

Sample: Image Operations using Dataverse Web API

Prerequisites

How to run the sample

Sample Output

Demonstrates

Create an image column

Create account records with image data

Retrieve the account records

Download the account record images

Download with Actions

Download with Chunks

Download with Stream

Delete the image data

Clean up

See Also

Feedback

Feedback

Additional resources