1. 首先，在Blazor WebAssembly项目中安装pdf.js包，可以通过命令行或NuGet包管理器来执行此操作。

2. 在Blazor组件中添加以下代码，将pdf.js库和pdf.worker.js文件引入到您的项目中：

@inject IJSRuntime JsRuntime;
@implements IDisposable

private IJSObjectReference pdfjsLibrary;
private IJSObjectReference pdfjsWorker;

protected override async Task OnInitializedAsync()
{
    pdfjsLibrary = await JsRuntime.InvokeAsync(
        "import", "./_content/pdfjs-dist/build/pdf.min.js");
    pdfjsWorker = await JsRuntime.InvokeAsync(
        "import", "./_content/pdfjs-dist/build/pdf.worker.min.js");

    await base.OnInitializedAsync();
}

public async ValueTask DisposeAsync()
{
    if (pdfjsWorker != null)
    {
        await pdfjsWorker.DisposeAsync();
        pdfjsWorker = null;
    }

    if (pdfjsLibrary != null)
    {
        await pdfjsLibrary.DisposeAsync();
        pdfjsLibrary = null;
    }
}

3. 然后，在Blazor组件中，您可以使用以下代码片段来检索pdf文件并将其从流中显示出来：

private async Task DisplayPdfAsync(DocumentFileStream documentStream)
{
    try
    {
        var memoryStream = new MemoryStream();
        await documentStream.CopyToAsync(memoryStream);
        memoryStream.Position = 0;
        await pdfjsWorker.InvokeVoidAsync("pdfjsWorkerGlobalScope.PDFJS.workerSrc",
            "./_content/pdfjs-dist/build/pdf.worker.min.js");

        var pdf = await pdfjsLibrary.InvokeAsync("getDocument", memoryStream.ToArray());
        var page = await pdf.InvokeAsync("getPage", 1);
        var scale = 1.5f;
        var viewport = await page.InvokeAsync("getViewport", (double)scale);

        var canvasRef = await canvasRefTask.Task;
        canvasRef.Width = viewport.width;
        canvasRef.Height = viewport.height;

        var renderOptions = new
        {
            canvasContext = await canvasRef.GetContext2DAsync(),
            viewport = viewport