[开发笔记]-C#获取pdf文档的页数

/// <summary>
/// 获取pdf文档的页数
/// </summary>
/// <param name="filePath"></param>
/// <returns>-1表示文件不存在</returns>
public static int GetPDFofPageCount(string filePath)
{
int count = -1;//-1表示文件不存在
if (File.Exists(filePath))
{
using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
StreamReader reader = new StreamReader(fs);
//从流的当前位置到末尾读取流
string pdfText = reader.ReadToEnd();
Regex rgx = new Regex(@"/Type\s*/Page[^s]");
MatchCollection matches = rgx.Matches(pdfText);
count = matches.Count;
}
}
return count;
}