Null Character Truncates String in Visual Basic

MORE INFORMATION

The SendKeys statement sends keystrokes to the active windows as if they were typed on the keyboard. Attempting to send a null character causes the string being sent to be truncated at the location of the null character.

You can use the MsgBox function to display a string expression as a message. However, if you use a string expression that contains the null character in the MsgBox function, the characters in the string after the null character do not display in the message box.

The Format function allows you to return an expression such as a string in a named or user-defined format. If you use the Format function in the Debug window to format a string expression that contains the null character, and if the null character is the first character in the string, the value 0 is returned.

Steps to Reproduce Behavior

The following Visual Basic procedure uses the SendKeys statement to send the word "Testing" to the active window:

   Sub Testing()
      SendKeys "Testing"
   End Sub
				

If you add a null character before the word Testing, the word "Testing" is not sent to the active window. In the following procedure, the keystrokes are not sent to the active window.

   Sub Testing()
      SendKeys Chr(0) + "Testing"
   End Sub
				

If a null character is placed between two (or more) concatenated strings, the string is truncated at the null character. In the following example, the word "Testing" is sent to the active window, but the string "One, Two, Three" is not.

   Sub Testing()
      SendKeys "Testing" + Chr(0)+ "One, Two, Three"
   End Sub
				

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