When using listdlg, what is the value assigned when the user exits without making a selection?

13 次查看（过去 30 天）
Zachary Holt
Zachary Holt 2019-11-1
评论： Zachary Holt 2019-11-2
I'm using listdlg to give the user a dropdown list to make a selection of. While debugging, I tried exiting the listdlg without making a selection, and I got an error.
I tried to validate the data underneath by using a while loop. Normally when a user exits a menu without making a selection, the variable is assigned to 0. My error is occurring almost 90 lines later, so as long as the data is validated, there shouldn't be any errors.
choice = listdlg("PromptString",{"Select a plant to learn more about."},"SelectionMode","single","ListString",CP);
while choice == 0 % forces user to make selection
choice = listdlg("PromptString",{"Select a plant to learn more about."},"SelectionMode","single","ListString",CP);
end
Since my while loop is just bypassed if the user exits without making a selection, that means the variable choice is not 0. If it's not assigned to 0 when the user exits without making a selection, what is the value assigned?

请先登录，再回答此问题。

采纳的回答

the cyclist
the cyclist 2019-11-1
Quoting the documentation for listdlg ...
"If the user clicks Cancel, presses Esc, or clicks the close button in the dialog box title bar, then the indx value is returned as an empty array."
So, I think you need
while isempty(choice)
instead of
while choice == 0

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Interactive Control and Callbacks 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by