求一正则， 取出字符中红色部分

Question

<tr>
                                                    <td>
                                                        <p align="center">
                                                            <img border="0" src="images/bmp-2.jpg" width="224" height="198">
                                                    </td>
                                                    <td width="180" rowspan="2">
                                                        <p align="center">
                                                            &nbsp;<b><font face="Arial" color="#000000">Download Datasheet<br>
                                                            </font></b><font face="Arial" color="#454545"><a target="_blank" href="pdf/BMP-2%20(CRP0801).pdf">
                                                                <img border="0" src="proteinexpression_files/pdf.gif" width="15" height="15"></a></font>
                                                    </td>
                                                </tr>

Answer 1

(?<=src=")[^"]+(?=")(?<=href=")[^"]+(?=")

Answer 2

你要说清楚规则
    <img border="0" src="images/bmp-2.jpg" width="224" height="198">
  <img border="0" src="proteinexpression_files/pdf.gif" width="15" height="15">为何只取第一个img中的src ，而不要第二个的src

Answer 3

(?i)<(?:img|a)\b[^>]*?(?:src|href)=(['"]?)(?<url>[^'"]+)\1[^>]*?>取Group["url"].Value

Answer 4

Regex reg = new Regex("(?<=[src|href]=\")(images|pdf)/[^\"]+(?=\")");