how to reset drop down list(go to first option) when pushing any other button in App designer

how can i reset drop down list (go to first option) when pushing any other button in App designer?

Answer 1

[Mario Malic]

You have to add callback to every 'any other button' component that'll reset it.

app.NameOfComponentDropDown.Value = app.NameOfComponentDropDown.Items(1);

[Hikmet Osman]

thanks

Answer 2

[Cris LaPierre]

In the callbacks for those other buttons, add the following code.

app.DropDown.Value = app.DropDown.Items(1);

[Hikmet Osman]

thanks...

Answer 3

[Hikmet Osman]

I created dropDown list like following:

% Create ElementLisDropDown

app.ElementLisDropDown = uidropdown(app.SelectionofTargetMaterialPanel);

app.ElementLisDropDown.Items = {'Select an element', ' 1: HYDROGEN', ' 2: HELIUM', ' 3: LITHIUM', ' 4: BERYLLIUM', ' 5: BORON'} ;

app.ElementLisDropDown.ItemsData = {'1', '2', '3', '4', '5'};

app.ElementLisDropDown.ValueChangedFcn = createCallbackFcn(app, @ElementLisDropDownValueChanged, true);

app.ElementLisDropDown.Position = [20 42 151 22];

app.ElementLisDropDown.Value = '1';

In the callbacks for other button, I added the following code:

app.ElementLisDropDown.Value=app.ElementLisDropDown.Items(1);

but I'm getting this error:

Error using matlab.ui.control.internal.model.ExactlyOneSelectionStrategy/validateValuePresentInItemsData (line 236)

'Value' must be an element defined in the 'ItemsData' property.

[Mario Malic]

I am not super familiar with interactions between Value and ItemsData properties. You have 6 Items and 5 ItemsData values, which might confuse MATLAB.

We don't know which line in your code is 236.

Answer 4

[Cris LaPierre]

You have changed your example. By default, ItemsData is empty, so the original responses set the value by indexing Items. For example, Items(1) is 'Select an element'.

From the documentation, "Notice that when the ItemsData property value is not empty, the value of the drop-down component is the ItemsData value that corresponds to the selected Items value element."

Because you've specified ItemsData, you must use those values to set the Value property, not Items. You can simplify the code in other callbacks to now be

app.ElementLisDropDown.Value='1';

What would probably make even more sense is to not define your ItemsData as text. Just use numbers.

Also be aware that you are one item short. The first ItemsData value corresponds to the first Items value. Currently, there is no ItemsData value for ' 5: BORON'

app.ElementLisDropDown.ItemsData = [1 2 3 4 5 6];
...
app.ElementLisDropDown.Value = 1;