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c# - 为什么删除事件后 Blazor UI 组件不更新？

问题描述

为什么删除事件后Blazor UI不更新：

我的组件：

<table class="table table-striped">
    <thead>
        <tr>
            <th>Id</th>
            <th>Name</th>
            <th>Example</th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var trainingTechnique in TrainingTechniques) {
        <tr>
            <td>@trainingTechnique.Id</td>
            <td>@trainingTechnique.Name</td>
            <td>@trainingTechnique.Example</td>
            <td>
                <button type="button" 
                        class="btn btn-danger" 
                        @onclick="@(async () => await DeleteTechnique(trainingTechnique.Id))">
                    Delete
                </button>

            </td>
        </tr>
        }
    </tbody>
</table>

我背后的组件代码：

public class TrainingTechniqueViewPageBase : ComponentBase
    {
        public List<TrainingTechniqueView> TrainingTechniques { get; set; }
        [Inject] 
        public ITrainingTechniqueConsumer TrainingTechniqueConsumer { get; set; }

        protected TrainingTechniqueForm TrainingTechniqueForm { get; set; } 
        protected override async Task OnInitializedAsync()
        {
            TrainingTechniques = (await TrainingTechniqueConsumer.GetTechniques()).ToList();
        }

        public async void TrainingTechniqueForm_OnSave()
        {
            TrainingTechniques = (await TrainingTechniqueConsumer.GetTechniques()).ToList();
            StateHasChanged();
        }

        protected void AddTrainingTechnique()
        {
            TrainingTechniqueForm.Show();
        }

        protected async Task DeleteTechnique(int id)
        {
           await (TrainingTechniqueConsumer.DeleteTrainingTechnique(id));
            this.StateHasChanged();

        }
    }
}

删除方法：

public async Task DeleteTrainingTechnique(int id)
{
    await _httpClient.DeleteAsync($"training/trainingtechniques/{id}");
}

标签： c#asp.net-coreasynchronousblazorblazor-server-side

解决方案

解决方案 1：从源重新加载 TrainingTechniques 列表

private async Task Delete(int id)
{
    await TrainingTechniqueConsumer.DeleteTrainingTechnique(id);
    TrainingTechniques = (await TrainingTechniqueConsumer.GetTechniques()).ToList();
}

解决方案 2：从列表中删除项目：

<table class="table table-striped">
    <thead>
        <tr>
            <th>Id</th>
            <th>Name</th>
            <th>Example</th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var trainingTechnique in TrainingTechniques)
        {
            <tr>
                <td>@trainingTechnique.Id</td>
                <td>@trainingTechnique.Name</td>
                <td>@trainingTechnique.Example</td>
                <td>
                    <button type="button" class="btn btn-danger" @onclick="@(() => DeleteTechnique(trainingTechnique.Id))">Delete</button>
                </td>
            </tr>
        }
    </tbody>
</table>

和删除方法：

private async Task Delete(int id)
{
    TrainingTechniques.RemoveAll(x => x.Id == Id);
    await TrainingTechniqueConsumer.DeleteTrainingTechnique(id);
}

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