The following is the correct spelling, you can try it. As for the reason, the construction method of JComboBox requires you to pass in a custom one.

ComboBoxModel, you don't need it here, just use the DefaultComboBoxModel that comes with JComboBox. Is to create with a parameterless construction method. Then call addItem to fill in the display data.

JComboBox comboBox = new JComboBox()；

comboBox.setBounds(50，50，50，50)；

for(int I = 1900； I & lt20 13; i++) {

combobox . additem(integer . value of(I))；

}

Add (combo box);

set visible(true)；