將一個項目（“ ---請選擇---”）添加到帶有數據源的組合框中

Question

我有一個帶有數據源的組合框，但我想添加一個項目。

我希望它看起來像這樣。

----Please select one---     //the item I want to add 
Tokyo                        //the items that came from the database
Osaka                        //the items that came from the database
Boston                       //the items that came from the database
Manila                       //the items that came from the database

我該如何補救？

謝謝

Answer 1

您需要在設置數據源之前將“請選擇”添加到要綁定的集合中，例如...

var countries = GetCountriesFromDatabase(); // Get countries from the database

countries.Insert(0, "----Please select one---"); // Insert your please select item

Combobox1.DataSource = countries; // Assign the datasource after inserting the item

Answer 2

Combobox1.DataSource = Yourdatasource; // this is your datasource
Combobox1.Items.Add("----Please select one---");