error-handling-patterns

Throw a UserFriendlyException with a localized message using L("Key") so the message displays directly to the user. You can pass a second localized string as details, and ABP automatically formats the response for the client.

Use UserFriendlyException for expected business rule violations where the message should reach the user. Standard exceptions are for unexpected errors; ABP logs them and shows only a generic message, never exposing internal details.

ABP automatically handles AbpAuthorizationException and AbpValidationException, returning appropriate user-facing responses without manual try-catch blocks. Use the AbpAuthorize attribute for permission checks and let validation attributes raise validation errors.

No, error messages should never be hardcoded. Always use the L() localization method with a resource key so messages can be translated and maintained centrally in localization files.

Query related data with the repository, such as counting dependent orders, and throw a UserFriendlyException if the rule is violated before calling DeleteAsync. Place this logic in the app service method guarded by the appropriate AbpAuthorize permission.