用于 Blazor 的 DevExpress dxDataGrid - "There was an unhandled exception on the current circuit" 错误

Question

我正在为 Blazor 使用 dxDataGrid 来构建项目，但是当我尝试添加新行时出现一些错误或编辑当前行。

Error: There was an unhandled exception on the current circuit, so this circuit will be terminated. For more details turn on detailed exceptions in 'CircuitOptions.DetailedErrors'. 
[2019-09-26T11:13:47.533Z] Information: Connection disconnected.

我收到了这个错误：

我第一个想到的 SignalR 是 disconnected.but 我不知道为什么或如何配置？

有人知道吗？可以告诉我吗？

根据 Mikhail 的建议，我得到了错误的一些新细节。第一次尝试时出现第一个错误，第二次尝试时出现第二个错误。

Error: System.NullReferenceException: Object reference not set to an instance of an object.
Uncaught (in promise) Error: Cannot send data if the connection is not in the 'Connected' State.

看来我的 code.but 有问题我仍然对这些错误没有任何想法，所以我将我的代码片段粘贴在下面。

<DxDataGrid Id="aa" Data="@activityDtos" @ref="@grid"
            ShowFilterRow="false"
            RowRemoving="@((dataItem) => OnRowRemoving(dataItem))"
            RowUpdating="@((updatingDataItem, newValues) => OnRowUpdating(updatingDataItem, newValues))"
            RowInserting="@((newValues) => OnRowInserting(newValues))">

    <DxDataGridCommandColumn Width="150px" Context="编辑"></DxDataGridCommandColumn>

    <DxDataGridColumn Field="@nameof(ActivityDto.ActivityCode)" Caption="Activity Code"></DxDataGridColumn>

    <DxDataGridColumn Field="@nameof(ActivityDto.ActText1)" Caption="Text1"></DxDataGridColumn>

    <DxDataGridColumn Field="@nameof(ActivityDto.ActText2)" Caption="Text2"></DxDataGridColumn>

    <DxDataGridColumn Field="@nameof(ActivityDto.ActivityStatusID)" Caption="Status">
        <DisplayTemplate>
            @{
                var feild = (context as ActivityDto).ActivityStatusID == "A" ? "Active" : "Inactive";
                <label><span>@feild</span></label>
            }
        </DisplayTemplate>
        <EditTemplate>
            <DxComboBox Data="@(new List<string>() { "Active", "Inactive" })"
                        SelectedItem="@(((bool)((CellEditContext)context).CellValue) ? "Active" : "Inactive" )"
                        SelectedItemChanged="@(newCellValue => ((CellEditContext)context).OnChanged(newCellValue == "Active"))">
            </DxComboBox>
        </EditTemplate>
    </DxDataGridColumn>

    <DxDataGridColumn Caption="Default">
        <DisplayTemplate>
            @{
                var id = Guid.NewGuid().ToString();
                var isDefault = (context as ActivityDto).IsDefault;
                <input id="@id" type="checkbox" checked="@isDefault" />
            }
        </DisplayTemplate>
    </DxDataGridColumn>

</DxDataGrid>

还有C#的代码

    string ActivityCode, Text1Value, Text2Value, Status,Status1;
IQueryable<ActivityDto> activityDtos;

ActivityFormDataItem editFormData = new ActivityFormDataItem()
{
    Status = "All",
    CompanyId = 37
};

protected override async Task OnInitializedAsync()
{
    activityDtos = await ActivitiesService.ActivitiesForAsync(editFormData);
    SearchDtos = await ActivitiesService.SearchDtosForAsync();
}

async void OnRowRemoving(ActivityDto dataItem)
{
    ActivitiesService.Remove(dataItem);
    await InvokeAsync(StateHasChanged);
}

async void OnRowUpdating(ActivityDto dataItem, Dictionary<string, object> newValue)
{
    ActivitiesService.Update(dataItem, newValue);
    await InvokeAsync(StateHasChanged);
}
async void OnRowInserting(Dictionary<string, object> newValue)
{
    ActivitiesService.Insert(newValue);
    await InvokeAsync(StateHasChanged);
}

protected async Task OnAfterRenderAsync()
{
    editFormData = new ActivityFormDataItem()
    {
        Status = Status1,
        ActivityCode=ActivityCode,
        CompanyId = 37,
        Text1Value=Text1Value,
        Text2Value=Text2Value
    };
    activityDtos = await ActivitiesService.ActivitiesForAsync(editFormData);
    if (!string.IsNullOrEmpty(editFormData.Status))
        editFormData.Status = editFormData.Status == "A" ? "Active" : "Inactive";
    else
        editFormData.Status = "All";
    await InvokeAsync(StateHasChanged);
}

Answer 1

查阅 There was an unhandled exception on the current circuit article and other recommendations from the official https://github.com/DevExpress/Blazor 存储库：

如果您看到此错误消息或类似消息，请将以下代码添加到 Startup.cs 文件中声明的 ConfigureServices 方法中：

services.AddServerSideBlazor().AddCircuitOptions(options => { options.DetailedErrors = true; });

一旦您能够获得更多详细信息，请将它们全部收集起来并提交 ticket 到 DevExpress 支持中心以获得专门的帮助。

Answer 2

我终于找到了为什么我的代码会出现这样的错误。编辑当前行时类型转换有问题。

<DxComboBox Data="@(new List<string>() { "Active", "Inactive" })"
                        SelectedItem="@(((bool)((CellEditContext)context).CellValue) ? "Active" : "Inactive" )"
                        SelectedItemChanged="@(newCellValue => ((CellEditContext)context).OnChanged(newCellValue == "Active"))">
            </DxComboBox>

其实我的思路不一样，浪费了很多时间

用于 Blazor 的 DevExpress dxDataGrid - "There was an unhandled exception on the current circuit" 错误

DevExpress dxDataGrid for Blazor - "There was an unhandled exception on the current circuit" error

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