1

我正在尝试建立一对多的关系。一家公司应该能够拥有多个董事会。我已经用这样的关系建立了我的模型。但是，我不确定如何调用正确的构造函数？当我使用 Create_Company 页面上的 EditForm 初始化对象时。

公司

public class Company
    {
        [Key]
        public Guid Id { get; set; }

        [Required]
        public string Name { get; set; }

        public DateTime Founded { get; set; }

        public List<Board> Boards { get; set; }

        public Company()
        {
        }

        public Company(string name, DateTime founded)
        {
            Name = name;
            Founded = founded;
            Boards = new List<Board>();
        }
    }

我知道如何使用：

private Company Company { get; set; } = new Company("", new DateTime());

但不是我目前的做法：

创建_公司

@page "/create_company"

@inject NavigationManager Navigation
@inject HttpClient Http

<div>
    <button class="btn btn-outline-secondary oi oi-arrow-left" @onclick="GoToReadCompany"></button>
    <h3 class="text-center">Create Company</h3>
</div>

<hr />

<hr />

<EditForm Model="Company" OnValidSubmit="@HandleValidSubmit">
    <ObjectGraphDataAnnotationsValidator />

    <div class="form-group row">
        <label for="Name" class="col-sm-2 col-form-label">Name</label>
        <div class="col-sm-10">
            <InputText id="Name" class="form-control" placeholder="Name" @bind-Value="Company.Name" />
            <ValidationMessage For="@(() => Company.Name)" />
        </div>
    </div>

    <div class="form-group row">
        <label for="CompanyFounded" class="col-sm-2 col-form-label">Founded</label>
        <div class="col-sm-10">
            <InputDate id="CompanyFounded" class="form-control" @bind-Value="Company.Founded" />
            <ValidationMessage For="@(() => Company.Founded)" />
        </div>
    </div>

    <hr />

    <div class="row justify-content-md-center">
        <button type="submit" class="btn btn-primary">Submit</button>
    </div>
</EditForm>

@code {
    private void GoToReadCompany()
    {
        Navigation.NavigateTo("/read_companies");
    }

    private Company Company { get; set; } = new Company();

    private async void HandleValidSubmit()
    {
        try
        {
            var response = await Http.PostAsJsonAsync("api/Companies", Company);
            response.EnsureSuccessStatusCode();

            await response.Content.ReadAsStringAsync();
            Navigation.NavigateTo("/read_companies");
        }
        catch (Exception)
        {

            Console.WriteLine("Exception occurred for POST company");
        }
    }
}
4

1 回答 1

1

您的问题似乎不是如何调用构造函数，而是何时调用。您可以在用户提交时使用新对象。然后使用新的公司对象。

    private async void HandleValidSubmit()
    {
        try
        {
            Company newCompany = new Company(Company.Name, Company.Founded);

            var response = await Http.PostAsJsonAsync("api/Companies", newCompany);
            response.EnsureSuccessStatusCode();

            await response.Content.ReadAsStringAsync();
            Navigation.NavigateTo("/read_companies");
        }
        catch (Exception)
        {

            Console.WriteLine("Exception occurred for POST company");
        }
    }
于 2021-12-29T17:42:01.400 回答