Prevent typing string in edit text

I have a problem. I want to create a edit text and then when I type a string in it, it will display nothing like a empty. That is to say it allows only numbers. I found some ways but they use push button for checking. Please help me.

Thank you in advance.

Answer 1

[Jan]

What does "only numbers" exactly mean? "1e3" is a number also.

What about checking the value inside the callback?

function Edit_Callback(hObject, EventData)
Str    = get(hObject, 'String');
Value  = sscanf(Str, '%g', 1);
fixStr = sprintf('%g', Value);
set(hObject, 'String', 'fixStr);

This tries to interprete the contents as 1 number and removes other characters.

[Quan Tran]

Thank you so much

But I have another problem :) When I typed '8.8*10^-7' in edit text, then I pushed enter button but it displayed '8.8'. How can I control it? I mean I want to type the mathematical symbol also.

[Walter Roberson]

You need to define all of the possible number formats, and then you need to write code that parses them. For example do you also allow 8.8E-7 ? 8.8d-7 ? .5e-7 ? 5E+007 ? 8.8+5.2i ? 8.8^-7 (where it is not 10 which is the base being raised) ? 8.8•10^+7 ? 8.8*10^—7 (notice that is one of the dashes, not a minus sign) ? 8.8*10ˆ7 (notice that is ˆ not ^) ？ 8.8·10^-7 ? 8.8×10^-7 ?

Answer 2

[Walter Roberson]

You can use a variation of http://www.mathworks.com/matlabcentral/fileexchange/24861-41-complete-gui-examples/content/GUI_37.m

Answer 3

[Daveed Daveed]

Hello. i was walking around here and i thought the following solution might be usefull for future people (may be the past time traveler :) )

function prevent_string(textbox_control)
if textbox_control.String ~= "" && isnan(str2double(textbox_control.String))
    textbox_control.String = "";
end

Answer 4

[Walter Roberson]

These days you would use a

uieditfield('numeric')

which requires uifigure() (and will not work for traditional figures)