自动刷新 Blazor 中的组件

Question

我正在处理用于添加新对象的 Blazor 页面。对象 "RepairOrder" 具有对象列表 "RepairSection"。

页面上有一个区域将循环遍历列表 "RepairOrder"。"RepairSections" 并显示元素：

   <div class="col-lg-10">
        @if (sections.Count > 0)
        {
            foreach (var sec in sections)
            {
                <h3>Section @sec.SectionNumber</h3>

                <div class="row">
                    <div class="col-lg-1"></div>
                    <div class="col-lg-5">
                        <label for="Failure" class="control-label">Failure: </label>
                        <input for="Failure" class="form-control" bind="@sec.Failure" readonly />
                    </div>
                    <div class="col-lg-1"></div>

                    <div class="col-lg-1">
                        <label><input type="checkbox" checked="@IsCApprovedChecked(sec)" />   Warranty</label>
                    </div>
                    <div class="col-lg-2">
                        <label><input type="checkbox" value="@IsWarrantyChecked(sec)" />   Repair Approved</label>
                    </div>
                </div>

                <div class="row">
                    <div class="col-lg-1"></div>
                    <div class="col-lg-10">
                        <label for="AdminComments" class="control-label">Admin Comments: </label>
                        <input for="AdminComments" class="form-control" bind="@sec.AdminComments" readonly />
                    </div>
                </div>
                <div class="row">
                    <div class="col-lg-1"></div>
                    <div class="col-lg-10">
                        <label for="TechComments" class="control-label">Tech Comments: </label>
                        <input for="TechComments" class="form-control" bind="@sec.TechComments" readonly />
                    </div>
                </div>
            }
        }
    </div>

列表中的所有当前栏目都添加到页面后，有一个按钮可以添加新栏目。单击按钮时，该函数将布尔值更改为 true 以将模态作为对话框打开。模态包含用于输入新部分元素的字段。

打开模式调用的函数：

protected void AddSectionCalled()
{
    _newSection = new RepairSection();
    this.isAddNew = true;
}

模态代码：

<div class="modal" tabindex="-1" style="display:block" role="dialog">
        <div class="modal-dialog modal-dialog-scrollable modal-xl">
            <div class="modal-content">
                <div class="modal-header">
                    <h3 class="modal-title">New Repair Section</h3>
                    <button type="button" class="close" onclick="@CloseModal"><span aria-hidden="true">X</span></button>
                </div>
                <div class="modal-body">
                    <form>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-2">
                                <label for="sectionLetter" class="control-label">Section: </label>
                                <input for="sectionLetter" class="form-control" bind="@_newSection.SectionNumber" />
                            </div>
                            <div class="col-lg-1"></div>

                            <div class="col-lg-2">
                                <label><input type="checkbox" bind="@_newSection.Warranty" />   Warranty</label>
                            </div>
                            <div class="col-lg-2">
                                <label><input type="checkbox" bind="@_newSection.CustomerApproved" />   Repair Approved</label>
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_failure" class="control-label">Failure: </label>
                                <input for="_failure" class="form-control" bind="@_newSection.Failure"/>
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_adminComments" class="control-label">Admin Comments: </label>
                                <input for="_adminComments" class="form-control" bind="@_newSection.AdminComments" />
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_techComments" class="control-label">Tech Comments: </label>
                                <input for="_techComments" class="form-control" bind="@_newSection.TechComments"/>
                            </div>
                        </div>
                        <br/>
                        <button class="btn btn-primary float-left" onclick="AddNewSection">Add New Section</button>
                    </form>
                </div>
            </div>
        </div>
    </div>

单击 "Add New Section" 按钮时，根据模态中收集的信息创建的“_newSection”对象将添加到 "sections" 最初在页面加载时循环的列表中。

   private void AddNewSection()
        {
            sections.Add(_newSection);
            this.StateHasChanged();            
            this.isAddNew = false;

        }

如您所见，我在新部分添加到部分列表后添加了 "StateHasChanged()"。但是，页面不会呈现以显示新部分。

我最初在页面 "OnInitAsync()" 事件上创建了虚拟数据，该事件在显示数据之前加载了部分列表。这样我就可以确保页面正确显示列表中的内容。

如何在用户向列表中添加新对象后让页面重新呈现列表中的信息？

----编辑-----

下面是整个页面的代码。我会尽量在周末尽量减少这种情况，但是这里真的没有很多。

 @page "/AddRepairOrder"
@using ShopLiveWebVersion2._0.Models
@using ShopLiveWebVersion2._0.DataAccess
@using ShopLiveWebVersion2._0.Services
@using ShopLiveWebVersion2._0.Data
@inject IUriHelper UriHelper
@inject RepairOrderContext context

<div class="row">
    <div class="col-lg-1"></div>
    <div class="col-lg-10"><h1>Create New Repair Order</h1></div>
</div>
<br /><br />
<form id="AddROForm">
    <div class="form-group">

        <div class="row">
            <div class="col-lg-1"></div>
            <div class="col-lg-2">
                <label for="ControlNumber" class="control-label">Repair Order #: </label>
                <input for="ControlNumber" class="form-control" bind="@ro.ControlNumber" maxlength="15" required />
            </div>
            <div class="col-lg-1">
                <label for="TagNumber" class="control-label">Tag #: </label>
                <input for="TagNumber" class="form-control" bind="@ro.TagNumber" maxlength="8" />
            </div>
            <div class="col-lg-3">
                <label for="VIN" class="control-label">VIN: </label>
                <input for="VIN" class="form-control" bind="@ro.VIN" maxlength="18" />
                @*<small id="Chasis" class="form-text text-muted">@ro.GetChassisNumber()</small> figure out how to get chassis from vin after box looses focus*@
            </div>
            <div class="col-lg-2">
                <label for="Make" class="control-label">Make: </label>
                <input for="Make" class="form-control" bind="@ro.Make" maxlength="30" />
            </div>
            <div class="col-lg-2">
                <label for="Madel" class="control-label">Model: </label>
                <input for="Madel" class="form-control" bind="@ro.Madel" maxlength="30" />
            </div>
        </div>

        <div class="row AddRow">
            <div class="col-lg-1"></div>
            <div class="col-lg-4">
                <label for="Customer" class="control-label">Customer: </label>
                <input for="Custoemr" class="form-control" bind="@ro.Customer" maxlength="50" />
            </div>
            <div class="col-lg-2">
                <label asp-for="Location" class="control-label">Vehicle Location: </label>
                <select asp-for="Location" class="form-control" bind="@ro.Location">
                    <option value="">-- Select a Location --</option>
                    @foreach (var loc in Location)
                    {
                        <option value="@loc">@loc</option>
                    }
                </select>
            </div>
            <div class="col-lg-2">
                <label asp-for="Assigned" class="control-label">Assigned: </label>
                <select asp-for="Assigned" class="form-control" bind="@ro.Assigned">
                    <option value="">-- Select an Employee --</option>
                    @foreach (var emp in Employee)
                    {
                        <option value="@emp">@emp</option>
                    }
                </select>
            </div>
            <div class="col-lg-2">
                <label asp-for="Status" class="control-label">Status: </label>
                <select asp-for="Status" class="form-control" bind="@ro.Status">
                    <option value="">-- Select a Status --</option>
                    @foreach (var st in Status)
                    {
                        <option value="@st">@st</option>
                    }
                </select>
            </div>
        </div>
        <br />
        <div class="row"><div class="col-lg-1"></div><div class="col-lg-10"><hr id="Double" /></div></div>
        <div class="row">
            <div class="col-lg-1"></div>
            <div class="col-lg-10">
                @if (sections.Count > 0)
                {
                    foreach (var sec in sections)
                    {
                        <h3>Section @sec.SectionNumber</h3>

                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-5">
                                <label for="Failure" class="control-label">Failure: </label>
                                <input for="Failure" class="form-control" bind="@sec.Failure" readonly />
                            </div>
                            <div class="col-lg-1"></div>

                            <div class="col-lg-1">
                                <label><input type="checkbox" checked="@IsCApprovedChecked(sec)" />   Warranty</label>
                            </div>
                            <div class="col-lg-2">
                                <label><input type="checkbox" value="@IsWarrantyChecked(sec)" />   Repair Approved</label>
                            </div>
                        </div>

                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="AdminComments" class="control-label">Admin Comments: </label>
                                <input for="AdminComments" class="form-control" bind="@sec.AdminComments" readonly />
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="TechComments" class="control-label">Tech Comments: </label>
                                <input for="TechComments" class="form-control" bind="@sec.TechComments" readonly />
                            </div>
                        </div>
                    }
                }
            </div>
        </div>
        <div class="row"></div>
    </div>    @*Form-group*@
</form>
<div class="row">
    <div class="col-lg-1"></div>
    <div class="col-lg-9">
        <br /><br />
        <button class="btn btn-primary float-right" onclick="@AddSectionCalled">Add New Section</button>
    </div>
</div>

@if (isAddNew == true)
{
    <div class="modal" tabindex="-1" style="display:block" role="dialog">
        <div class="modal-dialog modal-dialog-scrollable modal-xl">
            <div class="modal-content">
                <div class="modal-header">
                    <h3 class="modal-title">New Repair Section</h3>
                    <button type="button" class="close" onclick="@CloseModal"><span aria-hidden="true">X</span></button>
                </div>
                <div class="modal-body">
                    <form>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-2">
                                <label for="sectionLetter" class="control-label">Section: </label>
                                <input for="sectionLetter" class="form-control" bind="@_newSection.SectionNumber" />
                            </div>
                            <div class="col-lg-1"></div>

                            <div class="col-lg-2">
                                <label><input type="checkbox" bind="@_newSection.Warranty" />   Warranty</label>
                            </div>
                            <div class="col-lg-2">
                                <label><input type="checkbox" bind="@_newSection.CustomerApproved" />   Repair Approved</label>
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_failure" class="control-label">Failure: </label>
                                <input for="_failure" class="form-control" bind="@_newSection.Failure" />
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_adminComments" class="control-label">Admin Comments: </label>
                                <input for="_adminComments" class="form-control" bind="@_newSection.AdminComments" />
                            </div>
                        </div>
                        <div class="row">
                            <div class="col-lg-1"></div>
                            <div class="col-lg-10">
                                <label for="_techComments" class="control-label">Tech Comments: </label>
                                <input for="_techComments" class="form-control" bind="@_newSection.TechComments" />
                            </div>
                        </div>
                        <br />
                        <button class="btn btn-primary float-left" onclick="AddNewSection()">Add New Section</button>
                    </form>
                </div>
            </div>
        </div>
    </div>
}

@functions
{


    private RepairOrder ro;
    private RepairOrder incomingRO;
    private RepairOrderDataAccess RoData;
    private string chassis;
    private List<string> Location;
    private List<string> Employee;
    private List<string> Status;
    private FileService fileService;
    private List<RepairSection> sections;
    private bool isAddNew;

    //for new repair section modal
    private RepairSection _newSection;

    protected override async Task OnInitAsync()
    {
        ro = new RepairOrder();
        Location = new List<string>();
        Employee = new List<string>();
        Status = new List<string>();
        sections = new List<RepairSection>();
        isAddNew = false;
        fileService = new FileService();
        RoData = new RepairOrderDataAccess(context);
        await LoadData();

    }

    private async Task LoadData()
    {
        Location = await Task.Run(() => fileService.ReadLocation());
        Employee = await Task.Run(() => fileService.ReadEmployees());
        Status = await Task.Run(() => fileService.ReadStatus());

    }

    public string IsCApprovedChecked(RepairSection sc)
    {
        if (sc.CustomerApproved == true)
        {
            return "checked";
        }
        else
        {
            return "";
        }
    }

    public string IsWarrantyChecked(RepairSection sc)
    {
        if (sc.Warranty == true)
        {
            return "checked";
        }
        else
        {
            return "";
        }
    }

    protected void AddSectionCalled()
    {
        _newSection = new RepairSection();
        this.isAddNew = true;
    }

    private void AddNewSection()
    {
        sections.Add(_newSection);
        this.StateHasChanged();            
        this.isAddNew = false;

    }



    private void CloseModal()
    {
        this.isAddNew = false;
    }

Answer 1

您在模式窗体上绑定按钮的 onclick 事件的方式有问题。

你有 onclick="AddNewSection()" - 以这种方式编写它可能会被解释为纯 javascript 调用，如果您在浏览器工具中检查 DOM，您可能会在按钮上看到 onclick="AddNewSection()"。

你应该onclick="@AddNewSection" - 这样，Blazor 会将 onclick 事件连接到您的 C# 方法。

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