The ComboBox and ComboBoxEdit controls developed by Winform bind key/value data and comboboxkeyvalue

The ComboBox and ComboBoxEdit controls developed by Winform bind key/value data and comboboxkeyvalue

Bind the key/value using the ComboBox control:

Because ComboBox has the DataSource attribute, it can directly bind data sources, such as DataTable and ListItem.

Use DataTable to bind directly:

Public void BindSource () {DataTable dt = new DataTable (); dt. columns. add ("Text", Type. getType ("System. string "); dt. columns. add ("Value", Type. getType ("System. string "); dt. rows. add ("select", "0"); dt. rows. add ("option 1", "1"); dt. rows. add ("option 2", "2"); dt. rows. add ("option 3", "3"); comboBox1.DataSource = dt; comboBox1.DisplayMember = "Text"; // Text, that is, the explicit Text comboBox1.ValueMember = "Value "; // Value, that is, the actual Value comboBox1.SelectedIndex = 0; // set it to the first by default}

String text = this. comboBox1.Text; // obtain the selected text string value = this. comboBox1.SelectedValue. ToString (); // obtain the selected value

Use ListItem to implement key/value:

    public class ListItem : Object    {        public string Text { get; set; }        public string Value { get; set; }        public ListItem(string text,string value)        {            this.Text = text;            this.Value = value;        }        public override string ToString()        {            return this.Text;        }    }

Public void BindSource () {List <ListItem> list = new List <ListItem> (); list. add (new ListItem ("select", "0"); list. add (new ListItem ("option 1", "1"); list. add (new ListItem ("option 2", "2"); list. add (new ListItem ("option 3", "3"); comboBox1.DisplayMember = "Text"; // Text, that is, the explicit Text comboBox1.ValueMember = "Value "; // Value, that is, the actual Value comboBox1.DataSource = list; comboBox1.SelectedValue = "0"; // you can specify a Value of 0}

String text = (this. comboBox1.SelectedItem as ListItem). Text; // obtain the selected item text string value = (this. comboBox1.SelectedItem as ListItem). Value; // obtain the value of the selected item

 

Bind the key/value using the ComboBoxEdit control:

Because ComboBoxEdit does not have the DataSource attribute, you cannot bind the data source directly. You can add only one item.

    public class ListItem : Object    {        public string Text { get; set; }        public string Value { get; set; }        public ListItem(string text,string value)        {            this.Text = text;            this.Value = value;        }        public override string ToString()        {            return this.Text;        }    }

Public void BindSource () {string text = string. empty; string value = string. empty; ListItem item = null; for (int I = 0; I <4; I ++) {if (I = 0) {text = "select ";} else {text = "option" + I. toString ();} value = I. toString (); item = new ListItem (text, value); this. comboBoxEdit1.Properties. items. add (item );}}

When obtaining the value of the selected item, be sure to determine whether to select it.

String text = string. empty; string value = string. empty; if (comboBoxEdit1.SelectedIndex <0) // if it is less than 0, it indicates that it is not selected. if it is input, it is smaller than 0 {text = comboBoxEdit1.Text. trim (); // only the input text can be obtained} else {text = (comboBoxEdit1.SelectedItem as ListItem ). text; // obtain the selected Text value = (comboBoxEdit1.SelectedItem as ListItem ). value; // obtain the Value of the selected item}