The EN_MAXTEXT notification message is sent when the current text insertion has exceeded the specified number of characters for the edit control. The text insertion has been truncated.

当编辑框中的文本超过了指定字符数时，文本将被截断，同时父窗口收到此消息。

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The EN_SETFOCUS notification message is sent when an edit control receives the keyboard focus. The parent window of the edit control receives this notification message through a WM_COMMAND message.

当编辑框获得键盘焦点时（即编辑框由无光标变成有光标在闪烁时），父窗口收到这一消息。

youdao

The EN_SETFOCUS notification message is sent when an edit control receives the keyboard focus. The parent window of the edit control receives this notification message through a WM_COMMAND message.

当编辑框获得键盘焦点时（即编辑框由无光标变成有光标在闪烁时），父窗口收到这一消息。

youdao