Android alertDialog 动态添加edittext无法弹出键盘解决方案

严格来说这也不算是原创了，因为项目的原因需要在alertDialog根据spinner的选项动态生成控件，其中遇到一个恶心的问题，创建的edittext无法弹出键盘输入，找了很久，终于在stackoverflow里找到了方法。

问题的原因是这样的（我英文不好就不翻译了）：

OK, so after reading a lot, I have figured out why this is a problem, and I do not need to use any workarounds.

The problem seems to be (at least in my case), that since the place where you enter text is hidden initially (or nested or something), AlertDialog is automatically setting the flag WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM (or some combination of that and WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE) so that things don't trigger a soft input to show up.

解决的方法就是加入这一句：

dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);

dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);

http://stackoverflow.com/questions/9102074/android-edittext-in-dialog-doesnt-pull-up-soft-keyboard