<div class="cnblogs_code">

          IsNum(        </span><span style="color: #0000ff;"&gt;string</span> Rx = <span style="color: #800000;"&gt;@"</span><span style="color: #800000;"&gt;^[1-9]\d*$</span><span style="color: #800000;"&gt;"</span><span style="color: #000000;"&gt;;
        </span><span style="color: #0000ff;"&gt;if</span><span style="color: #000000;"&gt; (Regex.IsMatch(Str,Rx))
        {
            </span><span style="color: #0000ff;"&gt;return</span> <span style="color: #0000ff;"&gt;true</span><span style="color: #000000;"&gt;;
        }
        </span><span style="color: #0000ff;"&gt;else</span><span style="color: #000000;"&gt;
        {
            </span><span style="color: #0000ff;"&gt;return</span> <span style="color: #0000ff;"&gt;false</span><span style="color: #000000;"&gt;;
        }

    }</span></pre>