如何在 Blazor 客户端应用程序中使用 Bootstrap 模式？

Question

我试图显示引导模式然后绑定它的按钮。但是我无法通过显示模态的第一步。我正在使用 .net core 3.1 的 Blazor 客户端模板。我有一个名为 Modal.razor 的页面，其中包含我从 getbootstrap.com 找到的引导模式。

@if (Show)
{
    <div class="modal" tabindex="-1" role="dialog">
        <div class="modal-dialog" role="document">
            <div class="modal-content">
                <div class="modal-header">
                    <h5 class="modal-title">Modal title</h5>
                    <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                        <span aria-hidden="true">&times;</span>
                    </button>
                </div>
                <div class="modal-body">
                    <p>Modal body text goes here.</p>
                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-primary">Save changes</button>
                    <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
                </div>
            </div>
        </div>
    </div>
}
@code {
    [Parameter]
    public bool Show { get; set; } = false;
}

我在 index.razor 文件中调用了模态

@page "/"

<button @onclick="(()=>switchModal=!switchModal)">Switch Modal</button>

<Modal Show="switchModal"/>

@code{
    bool switchModal = false;
}

您可能会说应该在此处调用 StateHasChanged。但即使我将模态代码复制并粘贴到 index.razor 中，我也看不到任何东西。

Answer 1

可能有更好的方法来做到这一点，但这里有一个可以帮助您入门的工作示例：

页：

@page "/modal-test"

<BlazorApp1.Components.Modal @ref="Modal"></BlazorApp1.Components.Modal>

<button @onclick="() => Modal.Open()">Open Modal</button>

@code {
    private BlazorApp1.Components.Modal Modal { get; set; }
}

成分：

<div class="modal @ModalClass" tabindex="-1" role="dialog" style="display:@ModalDisplay">
    <div class="modal-dialog" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title">Modal title</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                    <span aria-hidden="true">&times;</span>
                </button>
            </div>
            <div class="modal-body">
                <p>Modal body text goes here.</p>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-primary">Save changes</button>
                <button type="button" class="btn btn-secondary" data-dismiss="modal" @onclick="() => Close()">Close</button>
            </div>
        </div>
    </div>
</div>


@if (ShowBackdrop)
{
    <div class="modal-backdrop fade show"></div>
}


@code {


  public Guid Guid = Guid.NewGuid();
    public string ModalDisplay = "none;";
    public string ModalClass = "";
    public bool ShowBackdrop = false;

    public void Open()
    {
        ModalDisplay = "block;";
        ModalClass = "Show";
        ShowBackdrop = true;
        StateHasChanged();
    }

    public void Close()
    {
        ModalDisplay = "none";
        ModalClass = "";
        ShowBackdrop = false;
        StateHasChanged();
    }
}

解决此问题的另一种选择是使用 JSInterop 调用 $('#modalId').modal()

你可以通过做这样的事情让组件的每个版本都有一个唯一的 id： <div id="bootstrap-modal-@Guid"然后使用保存的 ID 用 jQuery 调用 .modal() 。

Answer 2

基于 Kyle 的回答，这是我对 Blazor 的第一个实验：使模态对话框组件采用任何标记或组件。

Modal.razor

<div class="modal @modalClass" tabindex="-1" role="dialog" style="display:@modalDisplay; overflow-y: auto;">
    <div class="modal-dialog modal-lg" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title">@Title</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close" @onclick="Close">
                    <span aria-hidden="true">&times;</span>
                </button>
            </div>
            <div class="modal-body">
                @Body
            </div>
            <div class="modal-footer">
                @Footer
            </div>
        </div>
    </div>
</div>

@if (showBackdrop)
{
    <div class="modal-backdrop fade show"></div>
}

@code {
    [Parameter]
    public RenderFragment Title { get; set; }

    [Parameter]
    public RenderFragment Body { get; set; }

    [Parameter]
    public RenderFragment Footer { get; set; }

    private string modalDisplay = "none;";
    private string modalClass = "";
    private bool showBackdrop = false;

    public void Open()
    {
        modalDisplay = "block;";
        modalClass = "show";
        showBackdrop = true;
    }

    public void Close()
    {
        modalDisplay = "none";
        modalClass = "";
        showBackdrop = false;
    }
}

Index.razor

@page "/"

<h1>Hello, world!</h1>

Welcome to your new app.
<button class="btn btn-primary" @onclick="() => modal.Open()">Modal!</button>

<Modal @ref="modal">
    <Title>This is a <em>Title!</em></Title>
    <Body>
        <p>
            Lorem ipsum dolor sit amet, consectetur adipiscing elit. Omnes enim iucundum motum, quo sensus hilaretur.
            <i>Quis istud possit, inquit, negare?</i>
            <mark>Ego vero isti, inquam, permitto.</mark> Duo Reges: constructio interrete.
        </p>
        <FetchData />
        <dl>
            <dt><dfn>Stoici scilicet.</dfn></dt>
            <dd>An hoc usque quaque, aliter in vita?</dd>
            <dt><dfn>Erat enim Polemonis.</dfn></dt>
            <dd>Quod cum accidisset ut alter alterum necopinato videremus, surrexit statim.</dd>
        </dl>
    </Body>
    <Footer>
        <button type="button" class="btn btn-primary">Save changes</button>
        <button type="button" class="btn btn-secondary" data-dismiss="modal" @onclick="() => modal.Close()">Close</button>
    </Footer>
</Modal>

@code {
    private Modal modal { get; set; }
}

Answer 3

使用凯尔解决方案，当我单击背景时，我的对话框不会关闭。

我发现这是 z-index 的问题：模态 div 的 z-index 为 1050，背景 div 的 z-index 为 1040，这样我就无法单击我的背景。

我已将背景移动到对话框 div 内并添加到模态对话框 div z-index > 1040(ES: 1055)

我还添加data-dismiss="modal" @onclick="() => Close()"了背景 div，现在它和“关闭”按钮一样有效。

<div class="modal @ModalClass" tabindex="-1" role="dialog" style="display:@ModalDisplay">

    <div class="modal-dialog" role="document" style="z-index:1055">
       ...
    </div>    

@if (ShowBackdrop)
{
    <div class="modal-backdrop fade show"  data-dismiss="modal" @onclick="() => Close()"></div>
}

</div>

Answer 4

同样基于 Kyle 的回答，如果您在显示和类调整之间放置一个短暂的延迟，您可以维持引导淡入淡出效果。

@code {

    ...

    public async Task OpenModal()
    {
        ModalDisplay = "block;";
        await Task.Delay(100);//Delay allows bootstrap to perform nice fade animation
        ModalClass = "show";
        StateHasChanged();
    }

    public async Task CloseModal()
    {
        ModalClass = "";
        await Task.Delay(250);
        ModalDisplay = "none;";
        StateHasChanged();
    }
}

我也将 ModalClass 和 ModalDisplay 变量应用于背景元素

<div class="modal-backdrop fade @ModalClass" style="display: @ModalDisplay"></div>

我相信 bootstrap 可以通过这种方式更好地识别触发动画的状态变化