itextsharp：如何找到矩形的填充颜色 [英] itextsharp: How to find the fill color of a rectangle

问题描述

我按照ItextSharp示例获取图形结构，获取矩形坐标，使用代码：

I follow ItextSharp example for getting a graphical structure, to get the rectangle coordinates, using code:

class VectorGraphicsListener : IExtRenderListener
{
public void ModifyPath(PathConstructionRenderInfo renderInfo)
{
    if (renderInfo.Operation == PathConstructionRenderInfo.RECT)
    {
        float x = renderInfo.SegmentData[0];
        float y = renderInfo.SegmentData[1];
        float w = renderInfo.SegmentData[2];
        float h = renderInfo.SegmentData[3];  
...      

我尝试了renderInfo.GetFillColor（）;
但是没有这样的方法。

I tried the renderInfo.GetFillColor(); but there is no such a method.

我想获得额外的矩形属性：

像矩形填充颜色，（有些模拟到DIV style =background：blue; border：black;html中的标签）
我是怎么得到的？

I want to get additional rectangle properties :
like rectangle fill color,( some analog to DIV style="background: blue; border:black;" tag in html) how I get it ?

推荐答案

页面亚历山大在他的回答中发布了一个链接是我之前的回复堆栈溢出。

因此，我只是将该答案（使用iText / Java）的代码移植到iTextSharp / C＃：

Thus, I simply ported the code from that answer (which was using iText / Java) to iTextSharp / C#:

class ExtRenderListener : IExtRenderListener
{
    public void BeginTextBlock() { }
    public void RenderText(TextRenderInfo renderInfo) { }
    public void EndTextBlock() { }
    public void RenderImage(ImageRenderInfo renderInfo) { }

    public void ModifyPath(PathConstructionRenderInfo renderInfo)
    {
        pathInfos.Add(renderInfo);
    }

    public iTextSharp.text.pdf.parser.Path RenderPath(PathPaintingRenderInfo renderInfo)
    {
        GraphicsState graphicsState = getGraphicsState(renderInfo);
        Matrix ctm = graphicsState.GetCtm();

        if ((renderInfo.Operation & PathPaintingRenderInfo.FILL) != 0)
        {
            Console.Write("FILL ({0}) ", toString(graphicsState.FillColor));
            if ((renderInfo.Operation & PathPaintingRenderInfo.STROKE) != 0)
                Console.Write("and ");
        }
        if ((renderInfo.Operation & PathPaintingRenderInfo.STROKE) != 0)
        {
            Console.Write("STROKE ({0}) ", toString(graphicsState.StrokeColor));
        }

        Console.Write("the path ");

        foreach (PathConstructionRenderInfo pathConstructionRenderInfo in pathInfos)
        {
            switch (pathConstructionRenderInfo.Operation)
            {
                case PathConstructionRenderInfo.MOVETO:
                    Console.Write("move to {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.CLOSE:
                    Console.Write("close {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.CURVE_123:
                    Console.Write("curve123 {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.CURVE_13:
                    Console.Write("curve13 {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.CURVE_23:
                    Console.Write("curve23 {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.LINETO:
                    Console.Write("line to {0} ", toString(transform(ctm, pathConstructionRenderInfo.SegmentData)));
                    break;
                case PathConstructionRenderInfo.RECT:
                    Console.Write("rectangle {0} ", toString(transform(ctm, expandRectangleCoordinates(pathConstructionRenderInfo.SegmentData))));
                    break;
            }
        }
        Console.WriteLine();

        pathInfos.Clear();
        return null;
    }

    String toString(IList<float> coordinates)
    {
        StringBuilder result = new StringBuilder();
        result.Append("[ ");
        for (int i = 0; i < coordinates.Count; i++)
        {
            result.Append(coordinates[i]);
            result.Append(' ');
        }
        result.Append(']');
        return result.ToString();
    }

    List<float> transform(Matrix ctm, IList<float> coordinates)
    {
        List<float> result = new List<float>();
        for (int i = 0; i + 1 < coordinates.Count; i += 2)
        {
            Vector vector = new Vector(coordinates[i], coordinates[i + 1], 1);
            vector = vector.Cross(ctm);
            result.Add(vector[Vector.I1]);
            result.Add(vector[Vector.I2]);
        }
        return result;
    }

    List<float> expandRectangleCoordinates(IList<float> rectangle)
    {
        if (rectangle.Count < 4)
            return new List<float>();
        return new List<float>
        {
                rectangle[0], rectangle[1],
                rectangle[0] + rectangle[2], rectangle[1],
                rectangle[0] + rectangle[2], rectangle[1] + rectangle[3],
                rectangle[0], rectangle[1] + rectangle[3]
        };
    }

    String toString(BaseColor baseColor)
    {
        if (baseColor == null)
            return "DEFAULT";
        return String.Format("{0},{1},{2}", baseColor.R, baseColor.G, baseColor.B);
    }

    GraphicsState getGraphicsState(PathPaintingRenderInfo renderInfo)
    {
        System.Reflection.FieldInfo gsField = typeof(PathPaintingRenderInfo).GetField("gs", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        return (GraphicsState) gsField.GetValue(renderInfo);
    }

    public void ClipPath(int rule)
    {
    }

    List<PathConstructionRenderInfo> pathInfos = new List<PathConstructionRenderInfo>();
}

检索 GraphicsState所需的反射发生在方法 getGraphicsState 。

using (var pdfReader = new PdfReader([FILE TO PARSE]))
{
    IExtRenderListener extRenderListener = new ExtRenderListener();
    // Loop through each page of the document
    for (var page = 1; page <= pdfReader.NumberOfPages; page++)
    {
        Console.Write("\nPage {0}\n====\n", page);
        PdfReaderContentParser parser = new PdfReaderContentParser(pdfReader);
        parser.ProcessContent(page, extRenderListener);
    }
}

输出

对于以前的问题所涉及的PDF，此代码返回

Output

For the PDF that former question was about, this code returns

Page 1
====
STROKE (0,0,0) the path rectangle [ 88,3 693,69 227,77 693,69 227,77 788 88,3 788 ] 
STROKE (0,0,0) the path rectangle [ 227,77 693,69 367,24 693,69 367,24 788 227,77 788 ] 
STROKE (0,0,0) the path rectangle [ 367,23 693,69 506,7 693,69 506,7 788 367,23 788 ] 
FILL (255,0,0) the path rectangle [ 229,77 695,69 365,37 695,69 365,37 786,09 229,77 786,09 ] 
STROKE (DEFAULT) the path move to [ 228 810 ] line to [ 338 810 ]

（正如您在坐标输出中观察到的，我当前的语言环境使用逗号作为小数分隔符...）

(As you can observe in the coordinate outputs, my current locale uses a comma as decimal separator...)

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