The MATLAB App Designer application here requires the dynamic generation of dropdown menus based on file input. The file typically specifies both the number of dropdowns and their respective options, which are not known beforehand.
In dynamic creation of dropdown components in MATLAB App Designer, ensure that the storage structure is compatible with UI objects. If ‘app.presetDropdown’ is not explicitly declared as a cell array or object array, MATLAB may default to interpreting it as a numeric array, resulting in errors such as:
"Dot indexing is not supported for variables of this type."
To correctly store and manage multiple dropdowns, a cell array should be used, as UI components are object handles. The following code snippet demonstrates an approach for the same:
app.presetDropdown = cell(1, length(A));
for i = 1:length(A)
dd = uidropdown(app.UIFigure);
dd.FontSize = 16;
dd.Items = A{i};
dd.Position = [100, 300 - (i-1)*50, 150, 22];
app.presetDropdown{i} = dd;
end
This approach ensures that each dropdown is created and positioned distinctly. It also assumes that the variable A contains a cell array of item lists, one for each dropdown.
For more information, refer to the following documentations:
