//在界面构造函数里加入下面两行代码
this.cbbDepartureAirport.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.SuggestAppend;
this.cbbDepartureAirport.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.ListItems;
//在界面构造函数里加入下面两行代码
this.cbbDepartureAirport.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.SuggestAppend;
this.cbbDepartureAirport.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.ListItems;