使用水印

本主题讨论如何使用Aspose.Words以编程方式处理水印。 水印是在文档中的文本后面显示的背景图像。 水印可以包含由Watermark类表示的文本或图像。

为文档添加水印

在Microsoft Word中，可以使用Insert Watermark命令轻松地在文档中插入水印。 Aspose.Words提供watermark类以在文档中添加或删除水印。 Aspose.Words提供WatermarkType 枚举，定义三种可能的水印类型（文本、图像和无）。

添加文字水印

下面的代码示例演示如何通过使用SetText方法定义TextWatermarkOptions在文档中插入文本水印。

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
auto doc = System::MakeObject<Document>(inputDataDir + u"Document.doc");

auto options = System::MakeObject<TextWatermarkOptions>();
options->set_FontFamily(u"Arial");
options->set_FontSize(36);
options->set_Color(System::Drawing::Color::get_Black());
options->set_Layout(WatermarkLayout::Horizontal);
options->set_IsSemitrasparent(false);

doc->get_Watermark()->SetText(u"Test", options);

auto outputPath = outputDataDir + u"AddTextWatermark.docx";

doc->Save(outputPath);

添加图像水印

下面的代码示例演示如何通过使用SetImage方法定义ImageWatermarkOptions在文档中插入图像水印。

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
auto doc = System::MakeObject<Document>(inputDataDir + u"Document.doc");

auto options = System::MakeObject<ImageWatermarkOptions>();
options->set_Scale(5);
options->set_IsWashout(false);

doc->get_Watermark()->SetImage(System::Drawing::Image::FromFile(inputDataDir + u"Watermark.png"), options);

auto outputPath = outputDataDir + u"AddImageWatermark.docx";
doc->Save(outputPath);

水印也可以使用形状类插入。 将任何形状或图像插入页眉或页脚非常容易，从而创建任何可以想象的类型的水印。 下面的代码示例将水印插入到Word文档中。

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
namespace
{
    void InsertWatermarkIntoHeader(const System::SharedPtr<Paragraph>& watermarkPara, const System::SharedPtr<Section>& sect, HeaderFooterType headerType)
    {
        System::SharedPtr<HeaderFooter> header = sect->get_HeadersFooters()->idx_get(headerType);

        if (header == nullptr)
        {
            // There is no header of the specified type in the current section, create it.
            header = System::MakeObject<HeaderFooter>(sect->get_Document(), headerType);
            sect->get_HeadersFooters()->Add(header);
        }

        // Insert a clone of the watermark into the header.
        header->AppendChild((System::StaticCast<Node>(watermarkPara))->Clone(true));
    }

    void InsertWatermarkText(const System::SharedPtr<Document>& doc, const System::String& watermarkText)
    {
        // Create a watermark shape. This will be a WordArt shape. 
        // You are free to try other shape types as watermarks.
        System::SharedPtr<Shape> watermark = System::MakeObject<Shape>(doc, ShapeType::TextPlainText);
        watermark->set_Name(u"WaterMark");
        // Set up the text of the watermark.
        watermark->get_TextPath()->set_Text(watermarkText);
        watermark->get_TextPath()->set_FontFamily(u"Arial");
        watermark->set_Width(500);
        watermark->set_Height(100);
        // Text will be directed from the bottom-left to the top-right corner.
        watermark->set_Rotation(-40);
        // Remove the following two lines if you need a solid black text.
        watermark->get_Fill()->set_Color(System::Drawing::Color::get_Gray());
        // Try LightGray to get more Word-style watermark
        watermark->set_StrokeColor(System::Drawing::Color::get_Gray());
        // Try LightGray to get more Word-style watermark

        // Place the watermark in the page center.
        watermark->set_RelativeHorizontalPosition(RelativeHorizontalPosition::Page);
        watermark->set_RelativeVerticalPosition(RelativeVerticalPosition::Page);
        watermark->set_WrapType(WrapType::None);
        watermark->set_VerticalAlignment(VerticalAlignment::Center);
        watermark->set_HorizontalAlignment(HorizontalAlignment::Center);

        // Create a new paragraph and append the watermark to this paragraph.
        System::SharedPtr<Paragraph> watermarkPara = System::MakeObject<Paragraph>(doc);
        watermarkPara->AppendChild(watermark);

        // Insert the watermark into all headers of each document section.
        for (System::SharedPtr<Node> sectionNode : System::IterateOver(doc->get_Sections()))
        {
            System::SharedPtr<Section> sect = System::DynamicCast<Section>(sectionNode);
            // There could be up to three different headers in each section, since we want
            // The watermark to appear on all pages, insert into all headers.
            InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType::HeaderPrimary);
            InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType::HeaderFirst);
            InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType::HeaderEven);
        }
    }
}

void AddWatermark()
{
    std::cout << "AddWatermark example started." << std::endl;
    // The path to the documents directories.
    System::String inputDataDir = GetInputDataDir_WorkingWithImages();
    System::String outputDataDir = GetOutputDataDir_WorkingWithImages();
    System::SharedPtr<Document> doc = System::MakeObject<Document>(inputDataDir + u"TestFile.Watermark.doc");
    InsertWatermarkText(doc, u"CONFIDENTIAL");
    System::String outputPath = outputDataDir + u"AddWatermark.doc";
    doc->Save(outputPath);
    std::cout << "Added watermark to the document successfully." << std::endl << "File saved at " << outputPath.ToUtf8String() << std::endl;
    std::cout << "AddWatermark example finished." << std::endl << std::endl;
}

您可以从以下位置下载此示例的模板文件 Aspose.Words GitHub.

从文档中删除水印

Watermark类提供remove方法从文档中删除水印。

下面的代码示例演示如何从文档中删除水印:

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
auto doc = System::MakeObject<Document>(inputDataDir + u"TextWatermark.docx");
if (doc->get_Watermark()->get_Type() == WatermarkType::Text)
{
	doc->get_Watermark()->Remove();
}

auto outputPath = outputDataDir + u"RemoveWatermark.docx";
doc->Save(outputPath);

如果使用Shape类对象添加水印，那么要从文档中删除水印，您必须在插入过程中仅设置水印形状的名称，然后通过指定的名称删除水印形状。

下面的代码示例演示如何设置水印形状的名称并将其从文档中删除:

// Set name to be able to remove it afterwards
watermark->set_Name(u"WaterMark");

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
namespace
{
    void RemoveWatermarkText(const System::SharedPtr<Document>& doc)
    {
        System::SharedPtr<NodeCollection> headerFooterNodes = doc->GetChildNodes(NodeType::HeaderFooter, true);
        for (System::SharedPtr<HeaderFooter> hf : System::IterateOver<System::SharedPtr<HeaderFooter>>(headerFooterNodes))
        {
            System::SharedPtr<NodeCollection> shapeNodes = hf->GetChildNodes(NodeType::Shape, true);
            for (System::SharedPtr<Shape> shape: System::IterateOver<System::SharedPtr<Shape>>(shapeNodes))
            {
                if (shape->get_Name().Contains(u"WaterMark"))
                {
                    shape->Remove();
                }
            }
        }
    }
}

void RemoveWatermark()
{
    std::cout << "RemoveWatermark example started." << std::endl;
    // The path to the documents directories.
    System::String inputDataDir = GetInputDataDir_WorkingWithImages();
    System::String outputDataDir = GetOutputDataDir_WorkingWithImages();
    System::SharedPtr<Document> doc = System::MakeObject<Document>(inputDataDir + u"RemoveWatermark.docx");
    RemoveWatermarkText(doc);
    System::String outputPath = outputDataDir + u"RemoveWatermark.docx";
    doc->Save(outputPath);
    std:: cout << "File saved at " << outputPath.ToUtf8String() << std::endl;
    std::cout << "RemoveWatermark example finished." << std::endl << std::endl;
}

在表格单元格中添加水印

有时您需要将水印/图像插入表格的单元格并将其显示在表格之外，您可以使用IsLayoutInCell属性。 此属性获取或设置一个标志，该标志指示形状是显示在表内部还是表外部。 请注意，仅当您使用OptimizeFor方法优化Microsoft Word2010的文档时，此属性才有效。

下面的代码示例演示如何使用此属性:

For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-C
System::SharedPtr<Document> doc = System::MakeObject<Document>(inputDataDir + u"LayoutInCell.docx");
System::SharedPtr<DocumentBuilder> builder = System::MakeObject<DocumentBuilder>(doc);

System::SharedPtr<Shape> watermark = System::MakeObject<Shape>(doc, ShapeType::TextPlainText);
watermark->set_RelativeHorizontalPosition(RelativeHorizontalPosition::Page);
watermark->set_RelativeVerticalPosition(RelativeVerticalPosition::Page);
watermark->set_IsLayoutInCell(true);
// Display the shape outside of table cell if it will be placed into a cell.

watermark->set_Width(300);
watermark->set_Height(70);
watermark->set_HorizontalAlignment(HorizontalAlignment::Center);
watermark->set_VerticalAlignment(VerticalAlignment::Center);

watermark->set_Rotation(-40);
watermark->get_Fill()->set_Color(System::Drawing::Color::get_Gray());
watermark->set_StrokeColor(System::Drawing::Color::get_Gray());

watermark->get_TextPath()->set_Text(u"watermarkText");
watermark->get_TextPath()->set_FontFamily(u"Arial");

watermark->set_Name(System::String::Format(u"WaterMark_{0}",System::Guid::NewGuid()));
watermark->set_WrapType(WrapType::None);

System::SharedPtr<Run> run = System::DynamicCast_noexcept<Run>(doc->GetChildNodes(NodeType::Run, true)->idx_get(doc->GetChildNodes(NodeType::Run, true)->get_Count() - 1));

builder->MoveTo(run);
builder->InsertNode(watermark);
doc->get_CompatibilityOptions()->OptimizeFor(MsWordVersion::Word2010);

System::String outputPath = outputDataDir + u"WorkingWithShapes.SetShapeLayoutInCell.docx";

// Save the document to disk.
doc->Save(outputPath);