使用水印

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

在线尝试

您可以使用我们的 免费在线文档水印 尝试此功能。

向文档添加水印

在 Microsoft Word 中，可以使用"插入水印"命令轻松地将水印插入到文档中。 Aspose.Words 提供了 watermark 类来添加或删除文档中的水印。 Aspose.Words 提供了 水印类型Enumeration，定义了三种可能使用的水印类型（文本、图像和无）。

添加文字水印

以下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-.NET
Document doc = new Document(dataDir + "Document.doc");

TextWatermarkOptions options = new TextWatermarkOptions()
{
    FontFamily = "Arial",
    FontSize = 36,
    Color = Color.Black,
    Layout = WatermarkLayout.Horizontal,
    IsSemitrasparent = false
};

doc.Watermark.SetText("Test", options);

doc.Save(dataDir + "AddTextWatermark_out.docx");

添加图片水印

以下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-.NET
Document doc = new Document(dataDir + "Document.doc");

ImageWatermarkOptions options = new ImageWatermarkOptions()
{
    Scale = 5,
    IsWashout = false
};

doc.Watermark.SetImage(Image.FromFile(dataDir + "Watermark.png"), options);

doc.Save(dataDir + "AddImageWatermark_out.docx");

也可以使用形状类插入水印。将任何形状或图像插入页眉或页脚中非常容易，从而创建任何可以想象的类型的水印。

以下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-.NET
[Test]
public void AddWatermark()
{
    Document doc = new Document(MyDir + "Document.docx");

    InsertWatermarkText(doc, "CONFIDENTIAL");
    doc.Save(ArtifactsDir + "WorkWithWatermark.AddWatermark.docx");
}

/// <summary>
/// Inserts a watermark into a document.
/// </summary>
/// <param name="doc">The input document.</param>
/// <param name="watermarkText">Text of the watermark.</param>
private void InsertWatermarkText(Document doc, string watermarkText)
{
    // Create a watermark shape, this will be a WordArt shape.
    Shape watermark = new Shape(doc, ShapeType.TextPlainText) { Name = "Watermark" };

    watermark.TextPath.Text = watermarkText;
    watermark.TextPath.FontFamily = "Arial";
    watermark.Width = 500;
    watermark.Height = 100;

    // Text will be directed from the bottom-left to the top-right corner.
    watermark.Rotation = -40;

    // Remove the following two lines if you need a solid black text.
    watermark.FillColor = Color.Gray; 
    watermark.StrokeColor = Color.Gray;

    // Place the watermark in the page center.
    watermark.RelativeHorizontalPosition = RelativeHorizontalPosition.Page;
    watermark.RelativeVerticalPosition = RelativeVerticalPosition.Page;
    watermark.WrapType = WrapType.None;
    watermark.VerticalAlignment = VerticalAlignment.Center;
    watermark.HorizontalAlignment = HorizontalAlignment.Center;

    // Create a new paragraph and append the watermark to this paragraph.
    Paragraph watermarkPara = new Paragraph(doc);
    watermarkPara.AppendChild(watermark);

    // Insert the watermark into all headers of each document section.
    foreach (Section sect in doc.Sections)
    {
        // There could be up to three different headers in each section.
        // Since we want the watermark to appear on all pages, insert it into all headers.
        InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HeaderPrimary);
        InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HeaderFirst);
        InsertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HeaderEven);
    }
}

private void InsertWatermarkIntoHeader(Paragraph watermarkPara, Section sect,
    HeaderFooterType headerType)
{
    HeaderFooter header = sect.HeadersFooters[headerType];

    if (header == null)
    {
        // There is no header of the specified type in the current section, so we need to create it.
        header = new HeaderFooter(sect.Document, headerType);
        sect.HeadersFooters.Add(header);
    }

    // Insert a clone of the watermark into the header.
    header.AppendChild(watermarkPara.Clone(true));
}

您可以从 Aspose.Words GitHub 下载本示例的示例文件。

从文档中删除水印

Watermark 类提供了remove 方法来从文档中删除水印。

以下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-.NET
Document doc = new Document(dataDir + "AddTextWatermark_out.docx");

if (doc.Watermark.Type == WatermarkType.Text)
{
    doc.Watermark.Remove();
}

doc.Save(dataDir + "RemoveWatermark_out.docx");

如果使用 Shape 类对象添加水印，则要从文档中删除水印，您必须在插入期间仅设置水印形状的名称，然后通过分配的名称删除水印形状。

以下代码示例向您展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.Name("WaterMark");

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-.NET
public static void Run()
{          
    // The path to the documents directory.
    string dataDir = RunExamples.GetDataDir_WorkingWithImages();
    string fileName = "RemoveWatermark.docx";
    Document doc = new Document(dataDir + fileName);
    RemoveWatermarkText(doc);
    dataDir = dataDir + RunExamples.GetOutputFilePath(fileName);
    doc.Save(dataDir);
}

private static void RemoveWatermarkText(Document doc)
{
    foreach (HeaderFooter hf in doc.GetChildNodes(NodeType.HeaderFooter, true))
    {
        foreach (Shape shape in hf.GetChildNodes(NodeType.Shape, true))
        {
            if (shape.Name.Contains("WaterMark"))
            {
                shape.Remove();
            }
        }
    }
}
    }

将水印添加到表格单元格中

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外，您可以使用 IsLayoutInCell 属性。此属性获取或设置一个标志，指示形状是显示在表格内部还是表格外部。请注意，仅当您使用 OptimizeFor 方法针对 Microsoft Word 2010 优化文档时，此属性才起作用。

以下代码示例展示了如何使用此属性：

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-.NET
Document doc = new Document(dataDir + @"LayoutInCell.docx");
DocumentBuilder builder = new DocumentBuilder(doc);

Shape watermark = new Shape(doc, ShapeType.TextPlainText);
watermark.RelativeHorizontalPosition = RelativeHorizontalPosition.Page;
watermark.RelativeVerticalPosition = RelativeVerticalPosition.Page;
watermark.IsLayoutInCell = true; // Display the shape outside of table cell if it will be placed into a cell.

watermark.Width = 300;
watermark.Height = 70;
watermark.HorizontalAlignment = HorizontalAlignment.Center;
watermark.VerticalAlignment = VerticalAlignment.Center;

watermark.Rotation = -40;
watermark.Fill.Color = Color.Gray;
watermark.StrokeColor = Color.Gray;

watermark.TextPath.Text = "watermarkText";
watermark.TextPath.FontFamily = "Arial";

watermark.Name = string.Format("WaterMark_{0}", Guid.NewGuid());
watermark.WrapType = WrapType.None;

Run run = doc.GetChildNodes(NodeType.Run, true)[doc.GetChildNodes(NodeType.Run, true).Count - 1] as Run;

builder.MoveTo(run);
builder.InsertNode(watermark);
doc.CompatibilityOptions.OptimizeFor(MsWordVersion.Word2010);

dataDir = dataDir + "Shape_IsLayoutInCell_out.docx";

// Save the document to disk.
doc.Save(dataDir);