.NET 3.5 chart控件 Error executing child request for ChartImg.axd 错误处理办法
the error is thrown because the handler is configured incorrectly. To fix the issue modify the httpHandler configuration that user LaptopHeaven referred to in this topic by adding the POST verb:
<add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false" />
大意为：这个错误是由于没有正确设置httphandler产生的， 需要在web.config的<system.web>下的<httpHandlers>（如无手动输入）内加入如下标签
<add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false" />