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尝试从dot net core mvc下载使用openxml的word文档时出错

openxml-sdk openxml ms-word .net c#

Glory Raj · 技术社区 · 6 年前

我试图在dotnetcore中使用openxml插件生成word文档,方法是在控制器内部的action result方法中编写代码,如下所示

    public IActionResult CreateDocument()
    {
        using (MemoryStream mem = new MemoryStream())
        {
            using (WordprocessingDocument wordDoc = WordprocessingDocument.Create(mem, WordprocessingDocumentType.Document, true))
            {
                wordDoc.AddMainDocumentPart();
                Document doc = new Document();

                //Body body = new Body();

                /// Add header
                MainDocumentPart mainDocPart = wordDoc.MainDocumentPart;

                HeaderPart headerPart1 = mainDocPart.AddNewPart<HeaderPart>("r97");

                Header header1 = new Header();

                Paragraph paragraph1 = new Paragraph() { };
                Run run1 = new Run();
                Text text1 = new Text();
                text1.Text = "This is Header Part";

                run1.Append(text1);
                paragraph1.Append(run1);
                header1.Append(paragraph1);

                headerPart1.Header = header1;

                // getting an error here in this line
                SectionProperties sectionProperties1 = mainDocPart.Document.Body.Descendants<SectionProperties>().FirstOrDefault();  
                if (sectionProperties1 == null)
                {
                    sectionProperties1 = new SectionProperties() { };
                    mainDocPart.Document.Body.Append(sectionProperties1);
                }
                HeaderReference headerReference1 = new HeaderReference() { Type = HeaderFooterValues.Default, Id = "r97" };
                sectionProperties1.InsertAt(headerReference1, 0);
             .......
            ........
            .........
           }
        }
     }

SectionProperties sectionProperties1 = mainDocPart.Document.Body.Descendants<SectionProperties>().FirstOrDefault();

**Error:** DocumentFormat.OpenXml.Packaging.MainDocumentPart.Document.get returned null.

我不知道我在哪里做错了这个代码,请任何人提出任何关于这个的想法

非常感谢

0 回复 | 直到 6 年前

Lutti Coelho 6 年前

您可以实例化 mainDocPart 此行变量:
MainDocumentPart mainDocPart = wordDoc.MainDocumentPart;

那么您没有在其中添加任何文档。这就是为什么你会出错: DocumentFormat.OpenXml.Packaging.MainDocumentPart.Document.get returned null.

mainDocPart.Document = doc; //you define earlier but do not used.
doc.Body = new Body();
SectionProperties sectionProperties1 = 
mainDocPart.Document.Body.Descendants<SectionProperties>()?.FirstOrDefault();  
if (sectionProperties1 == null)
{
    sectionProperties1 = new SectionProperties() { };
    mainDocPart.Document.Body.Append(sectionProperties1);
}

Thomas Barnekow 6 年前

WordprocessingDocument 由一个 MainDocumentPart

<w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">
  <w:body />
</w:document>

因此,在创建“空”文档时,至少应具有以下代码:

using (var stream = new MemoryStream())
using (WordprocessingDocument wordDocument = WordprocessingDocument.Create(stream, WordprocessingDocumentType.Document))
{
    MainDocumentPart mainDocumentPart = wordDocument.AddMainDocumentPart();
    mainDocumentPart.Document = new Document(new Body());
}

请注意 w:document 和 w:body 元素与 Document Body

以创建标头为例,通常可以通过组合构造函数来简化代码,从而创建类似XML标记的结构,如下所示:

var headerPart = mainDocumentPart.AddNewPart<HeaderPart>();
headerPart.Header =
    new Header(
        new Paragraph(
            new Run(
                new Text("This is the Header Part"))));

在上面的代码示例中,我将代码布局为您将格式化相应的开放XML标记:

<w:hdr xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">
  <w:p>
    <w:r>
      <w:t>This is the Header Part</w:t>
    </w:r>
  </w:p>
</w:hdr>

在我看来,这更容易阅读,而且如果您了解创建所需结果所需的开放XML标记,就有助于避免错误。