有时候需要限制编辑框输入的字符，比如只允许输入字母字符，或者只允许输入数字字符，本例子通过派生一个CEdit类处理WM＿CHAR消息，然后从编辑控件中过滤特定的字符。-sometimes necessary to restrict the importation of the edit box characters, such as only allowing the importation of alphabetical characters, or allow only the import

this a delphi example ocr char-this is a delphi example ocr char