Windows Form ComboBox Text Filtering Drop Down

       static string[] x = { "Afghanistan", "Afgff", "Albania", "Bahrain", "Bhutan", "Cambodia", "Denmark", 
                                  "Egypt", "Finland", "Guyana", "Guinea", "Haiti", "Iceland", "Ireland", "Jamaica", "Jordan" };
       ArrayList flist = new ArrayList(x);
       public Form1()
       {
           InitializeComponent();

           this.cbxList.DropDownStyle = ComboBoxStyle.DropDown;
           this.cbxList.Items.AddRange(x);
           this.cbxList.AutoCompleteSource = AutoCompleteSource.ListItems;
           this.cbxList.AutoCompleteMode = AutoCompleteMode.Suggest;
       }

Breakdown of the ComboBox settings with help from MSDN

this.cbxList.DropDownStyle = ComboBoxStyle.DropDown;

http://msdn.microsoft.com/en-us/library/system.windows.forms.combobox.dropdownstyle.aspx
The DropDownStyle property specifies whether the list is always displayed or whether the list is displayed in a drop-down. That is, the different styles allowed are,

• Simple - list has no drop down arrow, text editable
• DropDown - list displayed by clicking down arrow and text is editable
• DropDownList - Similiar to DropDown but text is not editable

this.cbxList.Items.AddRange(x);

This just adds array of items to the ComboBox. http://msdn.microsoft.com/en-us/library/system.windows.forms.combobox.objectcollection.addrange.aspx

this.cbxList.AutoCompleteSource = AutoCompleteSource.ListItems;

Gets or sets a value specifying the source of complete strings used for automatic completion. http://msdn.microsoft.com/en-us/library/system.windows.forms.textbox.autocompletesource.aspx. Values available are,

• FileSystem
• HistoryList
• RecentlyUsedList
• AllUrl
• AllSystemSources
• FileSystemDirectories
• CustomSource
• None
• ListItems

More information at http://msdn.microsoft.com/en-us/library/system.windows.forms.autocompletesource.aspx

this.cbxList.AutoCompleteMode = AutoCompleteMode.Suggest;

Type of auto complete available

• None
• Suggest - filter appears at drop down
• Append - just appends the most likely string to the text
• SuggestAppend - Suggests AND Append

http://msdn.microsoft.com/en-us/library/system.windows.forms.autocompletemode.aspx