To achieve this, we can use the following namespace: "System.IO". Here is a custom code snippet, where the single parameter is the filePath parameter which is for accepting file path to validate size.
  1. public void ValidateFileSize(string filePath) {
  2. if (!File.Exists(filePath)) {
  3. //Throw error if file not found
  4. }
  5. FileInfo fileInfo = new FileInfo(filePath);
  6. //Validate Length
  7. if (fileInfo.Length / 1048 > 20) {
  8. //Throw error if file size is larger than your default/set size.
  9. }
  10. }
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