Sorting out qlineedit application technologies

Control the input range of qlineedit

 

1. Use a regular expression to check the input range of qlineedit (the Code is as follows ):

# Include <qvalidator. h>

# Include <qlineedit. h>

 

Qlineedit * lineedit = new qlineedit (this );

Qregexp Regexp ("[A-Za-Z] [1-9] [0-9] {0, 2 }"); // ^ [1-9] [0-9] * $ and ^ [1-9] {1} [/d] * $

// The regular expression above indicates that only positive integers greater than 0 can be entered.

Lineedit-> setvalidator (New qregexpvalidator (Regexp, this ));

 

##### Or use this

Qlineedit: add only letters and numbers to favorites

Qregexp regx ("[a-zA-Z0-9] + $ ");

Qvalidator * validator = new qregexpvalidator (regx, lined );

UI-> lined-> setvalidator (validator );

 

2. Use the qintvalidator integer verification control to control the input range of qlineedit (the Code is as follows ):

# Include <qvalidator. h>

# Include <qlineedit. h>

Qvalidator * validator = new qintvalidator (100,999, this );

Qlineedit * edit = new qlineedit (this );

// Only allow Edit to input an integer between 100 and 999

Edit-> setvalidator (validator );

 

 

 

Lineedit = qlineedit () instantiate an input box

 

Lineedit = setreadonly (true) # Set to read-only

 

Lineedit. setdragenabled (true) # Set to accept drag and drop

 

Lineedit. setmaxlength (5) # set the maximum length

 

Lineedit. selectall () # select all

 

Lineedit. setfocus () # Get focus

 

Lineedit. setinputmask ("dx") # You must enter two characters to modify the input box.

 

Punctuationre = qregexp (R "[,;:.]") # obtain a Regexp object. The following verification is available:

 

Lineedit. setvalidator (qregexpvalidator (qregexp (R "[0-9] +"), Self) # set verification to verify user input

 

Lineedit. emit (signal ('textchanged (qstring) ') signal (when set to read-only, it seems that no specific test is available)

 

Lineedit. emit (signal (textedited (qstring) ') sends a signal if it is set to verify that the signal can be issued only after it passes verification (when set to read-only, it seems that no specific test is available)