ASP.NET Core集成Playwright生成PDF时遇执行文件缺失及构建报错

问题场景 #

在ASP.NET Core中基于Playwright开发PDF生成服务，运行测试用例时出现Chromium执行文件缺失报错：

Executable doesn't exist at
C:\Users\wasys\AppData\Local\ms-playwright\chromium_headless_shell-1148\chrome-win\headless_shell.exe

尝试添加PostBuild脚本自动安装浏览器时，又出现构建报错：

Exception calling "ReadAllBytes" with "1" argument(s): "Could not find file
'D:\Temp\Solution.PdfGenerator\bin\Debug\net9.0\Microsoft.Playwright.dll'."
At D:\Temp\Solution.PdfGenerator\bin\Debug\net9.0\playwright.ps1:6 char:1

• [Reflection.Assembly]::Load([System.IO.File]::ReadAllBytes($playwrigh ...

• + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : FileNotFoundException
  

Unable to find type [Microsoft.Playwright.Program].
At D:\Temp\Solution.PdfGenerator\bin\Debug\net9.0\playwright.ps1:7 char:6

• exit [Microsoft.Playwright.Program]::Main($args)

• ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

  • CategoryInfo : InvalidOperation: (Microsoft.Playwright.Program:TypeName) [], RuntimeException
  • FullyQualifiedErrorId : TypeNotFound

PDF生成服务代码 #

public class PdfgeneratorService(IServiceProvider serviceProvider, ILoggerFactory loggerFactory) : IPdfgeneratorService
{
    public async Task GeneratePdf<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] TComponent>
                        (string fileName, Dictionary<string, object?> htmlData) where TComponent : IComponent
    {
        await using var htmlRenderer = new HtmlRenderer(serviceProvider, loggerFactory);

        var html = await htmlRenderer.Dispatcher.InvokeAsync(async () =>
        {
            var parameters = ParameterView.FromDictionary(htmlData);
            var output = await htmlRenderer.RenderComponentAsync(typeof(TComponent), parameters);
            return output.ToHtmlString();
        });

        using var playwright = await Playwright.CreateAsync();
        //ERROR IS APPEARING IN THIS LINE
        var browser = await playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions
        {
            Headless = true
        });

        var page = await browser.NewPageAsync();
        await page.SetContentAsync(html);

        await page.PdfAsync(new PagePdfOptions
        {
            Format = "A4",
            Path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory), $"{fileName.Replace(".pdf","")}.pdf")
        });

        await page.CloseAsync();
    }
}

测试代码 #

public class PdfgeneratorServiceTests
{
    private PdfgeneratorServiceTestBuilder builder;

    public PdfgeneratorServiceTests()
    {
        this.builder = new PdfgeneratorServiceTestBuilder();
    }

    [Fact]
    public async Task GeneratePdf_Success()
    {
        var invoice = InvoiceGenerator.Generate();

        var htmlDictionary = new Dictionary<string, object?>
        {
                { "Invoice", invoice }
        };

        var exception = await Record.ExceptionAsync(async () =>
            await builder.PdfgeneratorService.GeneratePdf<InvoiceView>("Test", htmlDictionary)
        );

        Assert.Null(exception);
    }
}

尝试的PostBuild脚本 #

<Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="powershell.exe -Command $(TargetDir)playwright.ps1 install chrome;" />
</Target>

解决方案 #

1. 替换PostBuild脚本，使用Playwright CLI安装浏览器 #

放弃依赖本地playwright.ps1的方式，直接通过dotnet工具调用Playwright CLI，避免dll路径依赖问题：

<Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="dotnet tool run playwright install chromium" />
</Target>

如果尚未安装Playwright CLI工具，先执行全局安装命令：

dotnet tool install --global Microsoft.Playwright.CLI

2. 手动触发浏览器安装（应急方案） #

如果构建脚本仍无法正常执行，可在项目根目录下手动运行以下命令，强制下载Chromium：

dotnet tool run playwright install chromium

3. 代码中手动指定浏览器路径（可选） #

若浏览器安装路径存在异常，可在LaunchAsync时显式指定Chromium的执行文件路径（替换XXXX为实际版本号）：

var browser = await playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions
{
    Headless = true,
    ExecutablePath = @"C:\Users\wasys\AppData\Local\ms-playwright\chromium-XXXX\chrome-win\chrome.exe"
});

4. 确保测试项目依赖完整 #

在测试项目中同样安装Microsoft.Playwright NuGet包，或在测试初始化逻辑中添加一次浏览器安装检查，避免测试运行时缺失依赖。

内容的提问来源于stack exchange，提问作者Wasyster