如何以适当的方式阅读PDF阿拉伯语内容?

时间:2018-11-18 17:27:06

标签: c# .net pdf

来源是:

$
الدرة الطَّقسية
للكنيسة القبطية
بين الكنائس الشرقية
مقدمات في طقوس الكنيسة
( 1 / 2 )
الكنائس الشَّرقيَّة وأوطانها
الجزء الأوَّل
رؤية عامة كنيسة المشرق الآشوريَّة

我得到的输出是:

- 
رؤية عامة كنيسة املشرق اآلش َّ ورية 
اجلزء األوَّل 
َّ الكنائس الش رقيَّة وأوطاهنا 





(1/2) 
مقدمات يف طقوس الكنيسة 
بني الكنـــائس الشرقية 
للكنيســة القبطية 
الدرة ا َّ لطقسية 
$ 

有些单词有空格并且顺序不同!

我将iTextSharp.text.pdf,iTextSharp.text.pdf.parser与以下代码结合使用:

class Program
{
    static void Main(string[] args)
    {
        string filepath = @"C:\Users\George\Desktop\George\church1.pdf";
        string result2=  GetTextFromPDF(filepath);

    }
    public static string GetTextFromPDF(string Path)
    {
        StringBuilder text = new StringBuilder();
        using (PdfReader reader = new PdfReader(Path))
        {
            for (int i = 1; i <= reader.NumberOfPages; i++)
            {
                if (i != 1) continue;
                text.Append(Bidi.BidiText(PdfTextExtractor.GetTextFromPage(reader, i, new LocationTextExtractionStrategy()), 1).Text );
            }
        }

        return text.ToString();
    }
}

public class BidiResult
{
    public string Text { set; get; }
    public bool IsRtl { set; get; }

    public BidiResult(string text, bool isRtl)
    {
        this.Text = text;
        this.IsRtl = isRtl;
    }
}
public static class Bidi
{
    /// <summary>
    /// Character types for symbols from 0000 to 00FF.
    /// </summary>
    public static string[] BaseTypes = new[] {
                            "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "S", "B", "S", "WS",
                            "B", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN",
                            "BN", "BN", "B", "B", "B", "S", "WS", "ON", "ON", "ET", "ET", "ET", "ON",
                            "ON", "ON", "ON", "ON", "ON", "CS", "ON", "CS", "ON", "EN", "EN", "EN",
                            "EN", "EN", "EN", "EN", "EN", "EN", "EN", "ON", "ON", "ON", "ON", "ON",
                            "ON", "ON", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "ON", "ON",
                            "ON", "ON", "ON", "ON", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "ON", "ON", "ON", "ON", "BN", "BN", "BN", "BN", "BN", "BN", "B", "BN",
                            "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN",
                            "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN", "BN",
                            "BN", "CS", "ON", "ET", "ET", "ET", "ET", "ON", "ON", "ON", "ON", "L", "ON",
                            "ON", "ON", "ON", "ON", "ET", "ET", "EN", "EN", "ON", "L", "ON", "ON", "ON",
                            "EN", "L", "ON", "ON", "ON", "ON", "ON", "L", "L", "L", "L", "L", "L", "L",
                            "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "ON", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L", "L",
                            "L", "L", "L", "ON", "L", "L", "L", "L", "L", "L", "L", "L"
                        };

    /// <summary>
    /// Character types for symbols from 0600 to 06FF
    /// </summary>
    public static string[] ArabicTypes = new[] {
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "CS", "AL", "ON", "ON", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM",
                            "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AN", "AN", "AN", "AN", "AN", "AN", "AN", "AN", "AN",
                            "AN", "ET", "AN", "AN", "AL", "AL", "AL", "NSM", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM",
                            "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "NSM", "ON", "NSM",
                            "NSM", "NSM", "NSM", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL",
                            "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL", "AL"
                        };

    public static bool IsOdd(int i)
    {
        return (i & 1) != 0;
    }

    public static bool IsEven(int i)
    {
        return (i & 1) == 0;
    }

    public static int FindUnequal(string[] arr, int start, string value)
    {
        int j;
        var jj = arr.Length;
        for (j = start; j < jj; ++j)
        {
            if (arr[j] != value)
                return j;
        }
        return j;
    }

    public static void SetValues(string[] arr, int start, int end, string value)
    {
        for (var j = start; j < end; ++j)
        {
            arr[j] = value;
        }
    }

    public static char[] ReverseValues(char[] arr, int start, int end)
    {
        var j = end - 1;
        for (var i = start; i < j; ++i, --j)
        {
            var temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }
        return arr;
    }

    public static char MirrorGlyphs(char c)
    {
        /*
         # BidiMirroring-1.txt
         0028; 0029 # LEFT PARENTHESIS
         0029; 0028 # RIGHT PARENTHESIS
         003C; 003E # LESS-THAN SIGN
         003E; 003C # GREATER-THAN SIGN
         005B; 005D # LEFT SQUARE BRACKET
         005D; 005B # RIGHT SQUARE BRACKET
         007B; 007D # LEFT CURLY BRACKET
         007D; 007B # RIGHT CURLY BRACKET
         00AB; 00BB # LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
         00BB; 00AB # RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
         */
        switch (c)
        {
            case '(':
                return ')';
            case ')':
                return '(';
            case '<':
                return '>';
            case '>':
                return '<';
            case ']':
                return '[';
            case '[':
                return ']';
            case '}':
                return '{';
            case '{':
                return '}';
            case '\u00AB':
                return '\u00BB';
            case '\u00BB':
                return '\u00AB';
            default:
                return c;
        }
    }

    public static BidiResult BidiText(string str, int startLevel)
    {
        var isLtr = true;
        var strLength = str.Length;
        if (strLength == 0)
            return new BidiResult(str, false);

        // get types, fill arrays

        var chars = new char[strLength];
        var types = new string[strLength];
        var oldtypes = new string[strLength];
        var numBidi = 0;

        for (var i = 0; i < strLength; ++i)
        {
            chars[i] = str[i];

            var charCode = str[i];
            string charType = "L";
            if (charCode <= 0x00ff)
                charType = BaseTypes[charCode];
            else if (0x0590 <= charCode && charCode <= 0x05f4)
                charType = "R";
            else if (0x0600 <= charCode && charCode <= 0x06ff)
                charType = ArabicTypes[charCode & 0xff];
            else if (0x0700 <= charCode && charCode <= 0x08AC)
                charType = "AL";

            if (charType == "R" || charType == "AL" || charType == "AN")
                numBidi++;

            oldtypes[i] = types[i] = charType;
        }

        // detect the bidi method
        //  if there are no rtl characters then no bidi needed
        //  if less than 30% chars are rtl then string is primarily ltr
        //  if more than 30% chars are rtl then string is primarily rtl
        if (numBidi == 0)
        {
            return new BidiResult(str, true);
        }

        if (startLevel == -1)
        {
            if ((strLength / numBidi) < 0.3)
            {
                startLevel = 0;
            }
            else
            {
                isLtr = false;
                startLevel = 1;
            }
        }

        var levels = new int[strLength];

        for (var i = 0; i < strLength; ++i)
        {
            levels[i] = startLevel;
        }

        /*
         X1-X10: skip most of this, since we are NOT doing the embeddings.
         */

        var e = IsOdd(startLevel) ? "R" : "L";
        var sor = e;
        var eor = sor;

        /*
         W1. Examine each non-spacing mark (NSM) in the level run, and change the
         type of the NSM to the type of the previous character. If the NSM is at the
         start of the level run, it will get the type of sor.
         */

        var lastType = sor;
        for (var i = 0; i < strLength; ++i)
        {
            if (types[i] == "NSM")
                types[i] = lastType;
            else
                lastType = types[i];
        }

        /*
         W2. Search backwards from each instance of a European number until the
         first strong type (R, L, AL, or sor) is found.  If an AL is found, change
         the type of the European number to Arabic number.
         */

        lastType = sor;
        for (var i = 0; i < strLength; ++i)
        {
            var t = types[i];
            if (t == "EN")
                types[i] = (lastType == "AL") ? "AN" : "EN";
            else if (t == "R" || t == "L" || t == "AL")
                lastType = t;
        }

        /*
         W3. Change all ALs to R.
         */

        for (var i = 0; i < strLength; ++i)
        {
            var t = types[i];
            if (t == "AL")
                types[i] = "R";
        }

        /*
         W4. A single European separator between two European numbers changes to a
         European number. A single common separator between two numbers of the same
         type changes to that type:
         */

        for (var i = 1; i < strLength - 1; ++i)
        {
            if (types[i] == "ES" && types[i - 1] == "EN" && types[i + 1] == "EN")
                types[i] = "EN";
            if (types[i] == "CS" && (types[i - 1] == "EN" || types[i - 1] == "AN") &&
                types[i + 1] == types[i - 1])
                types[i] = types[i - 1];
        }

        /*
         W5. A sequence of European terminators adjacent to European numbers changes
         to all European numbers:
         */

        for (var i = 0; i < strLength; ++i)
        {
            if (types[i] == "EN")
            {
                // do before
                for (var j = i - 1; j >= 0; --j)
                {
                    if (types[j] != "ET")
                        break;
                    types[j] = "EN";
                }
                // do after
                for (var j = i + 1; j < strLength; --j)
                {
                    if (types[j] != "ET")
                        break;
                    types[j] = "EN";
                }
            }
        }

        /*
         W6. Otherwise, separators and terminators change to Other Neutral:
         */

        for (var i = 0; i < strLength; ++i)
        {
            var t = types[i];
            if (t == "WS" || t == "ES" || t == "ET" || t == "CS")
                types[i] = "ON";
        }

        /*
         W7. Search backwards from each instance of a European number until the
         first strong type (R, L, or sor) is found. If an L is found,  then change
         the type of the European number to L.
         */

        lastType = sor;
        for (var i = 0; i < strLength; ++i)
        {
            var t = types[i];
            if (t == "EN")
                types[i] = (lastType == "L") ? "L" : "EN";
            else if (t == "R" || t == "L")
                lastType = t;
        }

        /*
         N1. A sequence of neutrals takes the direction of the surrounding strong
         text if the text on both sides has the same direction. European and Arabic
         numbers are treated as though they were R. Start-of-level-run (sor) and
         end-of-level-run (eor) are used at level run boundaries.
         */

        for (var i = 0; i < strLength; ++i)
        {
            if (types[i] == "ON")
            {
                var end = FindUnequal(types, i + 1, "ON");
                var before = sor;
                if (i > 0)
                    before = types[i - 1];
                var after = eor;
                if (end + 1 < strLength)
                    after = types[end + 1];
                if (before != "L")
                    before = "R";
                if (after != "L")
                    after = "R";
                if (before == after)
                    SetValues(types, i, end, before);
                i = end - 1; // reset to end (-1 so next iteration is ok)
            }
        }

        /*
         N2. Any remaining neutrals take the embedding direction.
         */

        for (var i = 0; i < strLength; ++i)
        {
            if (types[i] == "ON")
                types[i] = e;
        }

        /*
         I1. For all characters with an even (left-to-right) embedding direction,
         those of type R go up one level and those of type AN or EN go up two
         levels.
         I2. For all characters with an odd (right-to-left) embedding direction,
         those of type L, EN or AN go up one level.
         */

        for (var i = 0; i < strLength; ++i)
        {
            var t = types[i];
            if (IsEven(levels[i]))
            {
                if (t == "R")
                {
                    levels[i] += 1;
                }
                else if (t == "AN" || t == "EN")
                {
                    levels[i] += 2;
                }
            }
            else
            { // isOdd, so
                if (t == "L" || t == "AN" || t == "EN")
                {
                    levels[i] += 1;
                }
            }
        }

        /*
         L1. On each line, reset the embedding level of the following characters to
         the paragraph embedding level:

         segment separators,
         paragraph separators,
         any sequence of whitespace characters preceding a segment separator or
         paragraph separator, and any sequence of white space characters at the end
         of the line.
         */

        // don't bother as text is only single line

        /*
         L2. From the highest level found in the text to the lowest odd level on
         each line, reverse any contiguous sequence of characters that are at that
         level or higher.
         */

        // find highest level & lowest odd level

        var highestLevel = -1;
        var lowestOddLevel = 99;
        var ii = levels.Length;
        for (var i = 0; i < ii; ++i)
        {
            var level = levels[i];
            if (highestLevel < level)
                highestLevel = level;
            if (lowestOddLevel > level && IsOdd(level))
                lowestOddLevel = level;
        }

        // now reverse between those limits

        for (var level = highestLevel; level >= lowestOddLevel; --level)
        {
            // find segments to reverse
            var start = -1;
            ii = levels.Length;
            for (var i = 0; i < ii; ++i)
            {
                if (levels[i] < level)
                {
                    if (start >= 0)
                    {
                        chars = ReverseValues(chars, start, i);
                        start = -1;
                    }
                }
                else if (start < 0)
                {
                    start = i;
                }
            }
            if (start >= 0)
            {
                chars = ReverseValues(chars, start, levels.Length);
            }
        }

        /*
         L3. Combining marks applied to a right-to-left base character will at this
         point precede their base character. If the rendering engine expects them to
         follow the base characters in the final display process, then the ordering
         of the marks and the base character must be reversed.
         */

        // don't bother for now

        /*
         L4. A character that possesses the mirrored property as specified by
         Section 4.7, Mirrored, must be depicted by a mirrored glyph if the resolved
         directionality of that character is R.
         */

        // don't mirror as characters are already mirrored in the pdf

        // Finally, return string

        var result = string.Empty;
        ii = chars.Length;
        for (var i = 0; i < ii; ++i)
        {
            var ch = chars[i];
            if (ch != '<' && ch != '>')
                result += ch;
        }

        return new BidiResult(result, isLtr);
    }
}

0 个答案:

没有答案