绘制了在.NET Compact Framework的一个TextBox [英] Drawing over a TextBox in .NET Compact Framework

问题描述

是否有可能绘制过的.NET Compact Framework的一个TextBox控件？我想创建一个水印权。我已阅读这个答案。这是我目前最好的办法，但我不想限制自己显示水印，只有当文本框没有焦点。

Is it possible to draw over a TextBox control in .NET Compact Framework? I want to create a watermark over it. I have read this answer. It's currently my best approach, but I do not want to limit myself to displaying the watermark only when the TextBox does not have the focus.

我愿意尝试任何黑客！

推荐答案

如果我要做到这一点，我想创建一个派生自文本框控件，这样你得到所有的基础渲染，事件，文本和选择，亚达，亚达。我则P / Invoke来的SetWindowLong改变窗口处理程序，并在自定义处理程序处理WM_PAINT，在水印或任何你想要的绘制。

If I were to do this, I'd create a control that derives from TextBox, that way you get all of the base rendering, events, text and selection, yada-yada. I'd then P/Invoke to SetWindowLong to change the window handler, and handle WM_PAINT in a custom handler, drawing in the watermark or whatever you want.

有一个良好的基础的例子就是 OpenNETCF.Windows.Forms.TextBox2 类，这是否子类化到处理剪切/复制/粘贴操作。我相信，code自1.x的天一直存在，因此code是免费提供的（在上面的链接页面底部）如果你没有/想要最新的。

A good base example is the OpenNETCF.Windows.Forms.TextBox2 class that does this subclassing to handle cut/copy/paste operations. I believe that code has been there since the 1.x days, so the code is freely available (bottom of the page in the link above) if you don't have/want the latest.

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