如何使用 Aspose.Words 构建按需文档渲染的 API

using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/[controller]")]
public class RenderController : ControllerBase
{
    [HttpPost("render")]
    public IActionResult RenderDocument([FromForm] IFormFile file, [FromQuery] string format)
    {
        if (file == null || file.Length == 0)
        {
            return BadRequest("请上传有效的 Word 文档。");
        }

        string outputFormat = format.ToLower();
        string outputFilePath = $"RenderedDocument.{outputFormat}";

        try
        {
            using (var stream = new MemoryStream())
            {
                file.CopyTo(stream);
                stream.Position = 0;

                Document doc = new Document(stream);
                SaveFormat saveFormat = GetSaveFormat(outputFormat);

                using (var output = new MemoryStream())
                {
                    doc.Save(output, saveFormat);
                    return File(output.ToArray(), GetContentType(saveFormat), outputFilePath);
                }
            }
        }
        catch (Exception ex)
        {
            return StatusCode(500, $"发生错误：{ex.Message}");
        }
    }

    private SaveFormat GetSaveFormat(string format)
    {
        return format switch
        {
            "pdf" => SaveFormat.Pdf,
            "html" => SaveFormat.Html,
            "png" => SaveFormat.Png,
            _ => throw new NotSupportedException($"格式 {format} 不受支持。"),
        };
    }

    private string GetContentType(SaveFormat format)
    {
        return format switch
        {
            SaveFormat.Pdf => "application/pdf",
            SaveFormat.Html => "text/html",
            SaveFormat.Png => "image/png",
            _ => "application/octet-stream",
        };
    }
}