在 Blazor 中为 EditForm 建模数据时收到警告 BL0005

Question

我正在 Blazor HTML 部分中执行类似的操作...

<EditForm EditContext="editContext" OnValidSubmit="SubmitQuery">
    <DataAnnotationsValidator />
    <Microsoft.AspNetCore.Components.Forms.ValidationSummary />
    <InputRadioGroup @bind-Value="@Model.Selection">
        <InputRadio Value="FindGuestDisplay.Selections[0]" /><label>@(FindGuestDisplay.Selections[0]):</label>
        <br />
        <label class="fglabel">First Name:</label><InputText @bind-Value="@FirstName" style="width:300px" />
        <label class="fglabel">Last Name:</label><InputText @bind-Value="@LastName" style="width:300px" />

...

在代码部分中，我将模型设置器包装在本地属性中，如下所示......

private string FirstName { get { return Model!.FirstName ?? ""; } set { Model!.FirstName = value; } }
private string LastName { get { return Model!.LastName ?? ""; } set { Model.LastName = value; } }

我这样做是因为如果我直接使用模型属性，我会在整个代码中收到错误，这将警告限制为仅对设置器进行。

请注意，此代码有效，但我想以正确的方式执行此操作，无需发出警告。 顺便说一句，我所做的几乎完全按照微软使用编辑表单的示例所述的方式进行，那么我怎样才能摆脱这个错误呢？我应该使用合适的替代方案吗？

这是我的 Blazor 组件中的模型声明（未设置或从外部传入）：

FindGuestDisplay Model { get; set; }=  new ();

模型在此处传递到 editContext 中：

protected override void OnInitialized()
{
editContext = new(Model);
editContext.OnValidationRequested += HandleValidationRequested;
messageStore = new(editContext);
}

这是我的类定义：

public class FindGuestDisplay
{
    [Parameter]
    [StringLength(50, ErrorMessage = "Email is too long.")]
    public string Email { get; set; } = "";
    [Parameter]
    //[Required]
    [StringLength(15, ErrorMessage = "First Name is too long.")]
    public string FirstName { get; set; } = "";
    [Parameter]
    [StringLength(25, ErrorMessage = "Last Name is too long.")]
    public string LastName { get; set; } = "";
    [Parameter]
    [StringLength(15, ErrorMessage = "Cell Phone is too long.")]
    public string CellPhone { get; set; } = "";
    [Parameter]
    [StringLength(15, ErrorMessage = "Home Phone is too long.")]
    public string HomePhone { get; set; } = "";
    [Parameter]
    [StringLength(25, ErrorMessage = "Work Phone is too long.")]
    public string WorkPhone { get; set; } = "";

    [Parameter]
    [StringLength(50, ErrorMessage = "Business Name is too long.")]
    public string BusinessName { get; set; } = "";
    [Parameter]
    public string? BarcodeID { get; set; }

    public string Selection { get; set; } = "Enter Guest Information";
    public static readonly List<String> Selections = 
    [ "Enter Guest Information", "Find Web GuestPass", "Find Business" ];
}

如有任何帮助，我们将不胜感激。谢谢！

根据我的理解，我正在以正确的方式这样做。这只是一个糟糕的警告吗？

Answer 1

这是我使用的模式：

@page "/mypage"
@if (Model == null)
{
   return;
}
<div>First Name: @Model.FirstName</div> Model is not null here -> no warnings
@code
{
    MyPageModel? Model {get; set;}
    //Instantiate the model anywhere...
}

如果模型作为参数传递，我使用

required

关键字和

[EditorRequired]

:

[Parameter, EditorRequired]
public required MyPageModel {get; set;}