ValidationArgs.ResultAsync Property
Gets or sets a task that asynchronously posts changes to an underlying data source (database).
Namespace: DevExpress.Mvvm.Xpf
Assembly: DevExpress.Mvvm.v24.1.dll
NuGet Packages: DevExpress.Mvvm, DevExpress.Win.Navigation
Declaration
Property Value
Type | Description |
---|---|
Task<ValidationErrorInfo> | A task that asynchronously posts changes to an underlying data source (database). |
Remarks
If you want to update a row asynchronously, create a command and bind it to the ValidateRowCommand or ValidateNodeCommand property.
Use the ResultAsync property to specify a task that asynchronously posts changes to an underlying data source (database).
You can also validate data and specify an error description. If the data are invalid, the task should return the ValidationErrorInfo object; otherwise, return null.
To allow a user to cancel changes, set the UseCancellationToken property to true and use the CancellationToken in a cancel function.
[Command]
public void UpdateIssue(RowValidationArgs args) {
args.UseCancellationToken = true;
args.ResultAsync = UpdateIssueAsync(args.Item as IssueData, args.CancellationToken);
}
static async Task<ValidationErrorInfo> UpdateIssueAsync(IssueData issue, CancellationToken token) {
if(!IssuesService.ServerIsConnected)
return new ValidationErrorInfo("Server is disconnected.", ValidationErrorType.Critical);
await IssuesService.UpdateRowAsync(issue, token);
return null;
}
public async static System.Threading.Tasks.Task UpdateRowAsync(IssueData row, CancellationToken token) {
if(row == null)
return;
IssueData data = null;
for(int i = 0; i < AllIssues.Value.Length; i++) {
if(token.IsCancellationRequested)
return;
if(AllIssues.Value[i].Id == row.Id)
data = AllIssues.Value[i];
}
if(data == null)
return;
data.Priority = row.Priority;
data.Subject = row.Subject;
data.UserId = row.UserId;
data.Votes = row.Votes;
data.Created = row.Created;
await System.Threading.Tasks.Task.Delay(500).ConfigureAwait(false);
}
Limitation
Async validation for cells is not supported. The GridControl throws an exception if you specify the ResultAsync
property in the command bound to the GridViewBase.ValidateCellCommand property.
Related GitHub Examples
The following code snippets (auto-collected from DevExpress Examples) contain references to the ResultAsync property.
Note
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