通过StatusStrip访问 toolStripStatusLabel的属性

Form直接访问toolStripStatusLabel的属性,不能范围。报错。后来参考

http://stackoverflow.com/questions/29829936/how-to-update-toolstripstatuslabel-text-from-a-method-passing-all-the-controls-o

https://bytes.com/topic/c-sharp/answers/271395-mdi-statusstrip

才知道：

The Controls collection is not used on the ToolStrip and ToolStripContainer. You should use Items instead

所以应该这样用：

            ((StatusStrip)this.TopLevelControl.Controls["statusStrip1"]).Items["toolStripStatusLabel2"].Text = "Help"