WPF limits the contents of a TextBox entry

Restricts the text box TextBox's input, which is applied in many scenarios. For example, in a text box, you can only enter 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, "|" These 11 characters.

Restricting input 0-9 is easy to implement, and the key is this "|" Symbol. It corresponds to the Key.oempipe key in WPF. If the key is directly allowed to enter, then there will be "\" This symbol can also be entered. Then the question comes, how can we limit it? Simple: First make sure the SHIFT key is pressed.

The key code is as follows:

1 BOOL 0;

This allows the Key.oempiple key to be pressed to ensure that only the ' | ' is entered when we confirm that the SHIFT key has been pressed. Symbol.

A complete sample code is as follows:

1 Private voidTextbox_keydown_event (Objectsender, KeyEventArgs)2 {3             BOOLShiftkey = (Keyboard.modifiers & modifierkeys.shift)! =0;4             if(Shiftkey = =true)5             {6                 if(E.key! =key.oempipe)7                 {8e.handled =true;9                 }Ten             } One             Else if(E.key! = Key.delete && E.key! = Key.back && AE.key! = key.d0 && E.key! = key.d1 && -E.key! = Key.d2 && E.key! = key.d3 && -E.key! = key.d4 && E.key! = key.d5 && theE.key! = Key.d6 && E.key! = Key.d7 && -E.key! = Key.d8 && E.key! = key.d9 && -E.key! = key.numpad0 && E.key! = Key.numpad1 && -E.key! = key.numpad2 && E.key! = key.numpad3 && +E.key! = Key.numpad4 && E.key! = Key.numpad5 && -E.key! = Key.numpad6 && E.key! = Key.numpad7 && +E.key! = Key.numpad8 && E.key! =key.numpad9) A             { ate.handled =true; -             } -}

WPF limits the contents of a TextBox entry