mvc3里使用ViewBag，到底怎么用？

this.ViewBag.ABC= "123123";

@Html.TextBox("Name", this.ViewBag.ABC)

为什么这里一直提示错误呀？？
如何用ViewBag往@Html.TextBox赋值呢？？？
[解决办法]

@Html.TextBox("Name",ViewBag.ABC as object)

这样试一下
[解决办法]
@Html.TextBox("Name",ViewBag.ABC as string)