将线对象添加到PDF文件

以下代码片段也适用于Aspose.PDF.Drawing库。

添加线对象

Aspose.PDF for .NET支持将图形对象（例如图形、线条、矩形等）添加到PDF文档的功能。您还可以添加线对象，在其中您还可以指定虚线模式、颜色和其他线元素的格式。

请按照以下步骤操作：

1. 创建一个新的PDF 文档。

2. 将页面添加到PDF文件的页面集合中。

3. 创建图形实例。

4. 将图形对象添加到页面实例的段落集合中。

5. 创建矩形实例。

6. 设置线宽。

7. 将矩形对象添加到图形对象的形状集合中。

8. 保存您的PDF文件。

以下代码片段演示了如何添加一个填充颜色的矩形对象。

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AddLineObjectToPDF()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();

        // Create Graph instance
        var graph = new Aspose.Pdf.Drawing.Graph(100, 400);

        // Add graph object to paragraphs collection of page instance
        page.Paragraphs.Add(graph);

        // Create Line instance with specified coordinates
        var line = new Aspose.Pdf.Drawing.Line(new float[] { 100, 100, 200, 100 });

        // Specify dash settings for the line
        line.GraphInfo.DashArray = new int[] { 0, 1, 0 };
        line.GraphInfo.DashPhase = 1;

        // Add line object to shapes collection of Graph object
        graph.Shapes.Add(line);

        // Save PDF document
        document.Save(dataDir + "AddLineObject_out.pdf");
    }
}

如何将虚线添加到您的PDF文档

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void DashLengthInBlackAndDashLengthInWhite()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();

        // Create Drawing object with certain dimensions
        var canvas = new Aspose.Pdf.Drawing.Graph(100, 400);

        // Add drawing object to paragraphs collection of page instance
        page.Paragraphs.Add(canvas);

        // Create Line object
        var line = new Aspose.Pdf.Drawing.Line(new float[] { 100, 100, 200, 100 });

        // Set color for Line object
        line.GraphInfo.Color = Aspose.Pdf.Color.Red;

        // Specify dash array for line object
        line.GraphInfo.DashArray = new int[] { 3, 2 }; // Dash and gap lengths in points

        // Set the dash phase for Line instance
        line.GraphInfo.DashPhase = 1;

        // Add line to shapes collection of drawing object
        canvas.Shapes.Add(line);

        // Save PDF document
        document.Save(dataDir + "DashLengthInBlackAndDashLengthInWhite_out.pdf");
    }
}

让我们检查一下结果：

在页面上绘制线条

我们还可以使用线对象绘制一条从左下角到右上角的交叉线，以及从左上角到右下角的交叉线。

请查看以下代码片段以实现此要求。

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ExampleLineAcrossPage()
{
    // The path to the document directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();

        // Set page margin on all sides as 0
        page.PageInfo.Margin.Left = 0;
        page.PageInfo.Margin.Right = 0;
        page.PageInfo.Margin.Bottom = 0;
        page.PageInfo.Margin.Top = 0;

        // Create Graph object with Width and Height equal to page dimensions
        var graph = new Aspose.Pdf.Drawing.Graph(
            (float)page.PageInfo.Width,
            (float)page.PageInfo.Height);

        // Create first line object starting from Lower-Left to Top-Right corner of page
        var line1 = new Aspose.Pdf.Drawing.Line(new float[]
        {
            (float)page.Rect.LLX, 0,
            (float)page.PageInfo.Width,
            (float)page.Rect.URY
        });

        // Add line to shapes collection of Graph object
        graph.Shapes.Add(line1);

        // Create second line object starting from Top-Left corner to Bottom-Right corner of page
        var line2 = new Aspose.Pdf.Drawing.Line(new float[]
        {
            0, (float)page.Rect.URY,
            (float)page.PageInfo.Width, (float)page.Rect.LLX
        });

        // Add line to shapes collection of Graph object
        graph.Shapes.Add(line2);

        // Add Graph object to paragraphs collection of page
        page.Paragraphs.Add(graph);

        // Save PDF document
        document.Save(dataDir + "ExampleLineAcrossPage_out.pdf");
    }
}