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我需要将 @bind-SelectedValues 绑定到 ductionary 中的值。但它给出了 CS1503 参数 2：无法从 'Microsoft.AspNetCore.Components.EventCallback<System.Collections.Generic.List>' 转换为 'Microsoft.AspNetCore.Components.EventCallback'

<MudTable Items="users.UserList" Loading="@_loading" LoadingProgressColor="Color.Info">
    <HeaderContent>
        <MudTh>User</MudTh>
        <MudTh>Applications</MudTh>
        <MudTh>Edit</MudTh>
    </HeaderContent>
    <RowTemplate>
        <MudTd DataLabel="User">@context.FullName</MudTd>
        <MudTd DataLabel="Application">
            <MudSelect Variant="Variant.Outlined" T="int" Label="Applications" MultiSelection="true" 
                @bind-Value="value" 
                @bind-SelectedValues="userAppsDict[context.Id]">
                @foreach(var item in apps.ApplicationList)
                {
                    <MudSelectItem T="int" Value="@item.Id">@item.Name</MudSelectItem>
                }
            </MudSelect>
        </MudTd>
        <MudTd>
            <MudButton Color="Color.Primary" Variant="Variant.Filled">Update</MudButton>
        </MudTd>
    </RowTemplate>
</MudTable>

@code{
    [Inject]
    private IApplicationService service{ get; set; }
    private int value { get; set; }
    private IEnumerable<int> options { get; set; } = new HashSet<int>();
    private bool _loading = false;
    private Dictionary<int, List<int>> userAppsDict { get; set; } = new Dictionary<int, List<int>>();

    UserHasApplicationsReadViewModel userApps = new UserHasApplicationsReadViewModel();
    UserReadViewModel users = new UserReadViewModel();
    ApplicationReadViewModel apps = new ApplicationReadViewModel();

    protected override async Task OnInitializedAsync()
    {
        _loading = true;
        userApps = await service.GetUserHasApplications();
        users = await service.GetUsers();
        apps = await service.GetApplicationsAsync();

        foreach(var user in users.UserList)
        {
            List<int> appIdList = new List<int>();
            var appsbyUid = await service.GetApplicationByUserId(user.Id);
            foreach (var item in appsbyUid.ApplicationList)
            {
                appIdList.Add(item.Id);
            }
            userAppsDict.Add(user.Id, appIdList);
        }
        Console.WriteLine(JsonSerializer.Serialize(userAppsDict));
        _loading = false;
    }
}
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1 回答 1

0

我需要将 @bind-SelectedValues 绑定到 ductionary 中的值

需要是一个主观术语。MB 想要将一个字符串哈希集放入 SelectedValues 绑定中，因此阻力最小的路径是让它，然后反向翻译，可能是这样的：

@inject ISnackbar Snackbar

<MudTable Items="users" Loading="@_loading" LoadingProgressColor="Color.Info">
    <HeaderContent>
        <MudTh>User</MudTh>
        <MudTh>Applications</MudTh>
        <MudTh>Edit</MudTh>
    </HeaderContent>
    <RowTemplate>
        <MudTd DataLabel="User">@context.FullName</MudTd>
        <MudTd DataLabel="Application">
            <MudSelect Variant="Variant.Outlined" Label="Applications" MultiSelection="true" 
                @bind-SelectedValues="context.Apps">
                @foreach(var item in apps)
                {
                    <MudSelectItem Value="@item.Name">@item.Name</MudSelectItem>
                }
            </MudSelect>
        </MudTd>
        <MudTd>
            <MudButton Color="Color.Primary" Variant="Variant.Filled"  OnClick="@(() => UpdateUser(context))">Update</MudButton>
        </MudTd>
    </RowTemplate>
</MudTable>


@code{
    private bool _loading = false;

    List<User> users = new List<User>();
    List<App> apps = new List<App>();

    protected override async Task OnInitializedAsync()
    {
        _loading = true;
        apps = new List<App>{ 
            new(){
                Id = 1,
                Name = "FirstApp"
            },
            new(){
                Id = 2,
                Name = "SecondApp"
            }
        };
        users = new List<User>{
            new User{ 
                Id = 1,
                FullName = "Firstappuser",
                Apps = new HashSet<string>{ apps.First().Name }
            },
            new User{ 
                Id = 2,
                FullName = "Secondappuser",
                Apps = new HashSet<string>{ apps.Last().Name }
            },
            
        };
        _loading = false;
    }

    class User{
      public int Id {get;set;}
      public string FullName {get;set;}
      public IEnumerable<string> Apps {get;set;}
    }
    class App{
      public int Id {get;set;}
      public string Name {get;set;}
    }

    void UpdateUser(User u){
      var newApps = u.Apps.Select(a => apps.First(app => app.Name == a)).ToArray();
      Snackbar.Add("Updating user " + u.FullName + " to have apps " + string.Join(",", newApps.Select(app => app.Id.ToString())));
    }
}

我必须发明类来涵盖用例，但它也强调你不必使用你提供的类作为模型；随意做任何必要的事情来简单地建模事物。这里每个用户都有一个IEnumerable<string>将跟踪用户拥有的应用程序，而不是Dictionary<userid, List<app ids>>1：M 用户：应用程序关联在每个用户内部。当单击更新按钮时，用户被传递给处理程序，并且有一个过程将应用程序名称反转回应用程序（newApps然后我将他们的 ID 串入到快餐栏，以证明它能够将应用程序名称反转为应用程序，并改为获取 ID

https://try.mudblazor.com/snippet/cEQGkmwGgvbuyXTd

于 2022-02-22T16:59:39.350 回答