逐层遍历designerForm的子控件找到FlatDesigner类型;建议开发人员弄个专用的属性出来。
var designer= ((designerForm.Controls[0].Controls[2].Controls[0] as SplitContainer).Panel1.Controls[0] as SplitContainer).Panel2.Controls[0].Controls[0] as FlatDesigner;
designer.LocateDataSource += Designer_LocateDataSource;
Application.Run(designerForm);