windowsforms-devexpress-dot-xtraeditors-dot-controls-dot-querycheckstatebyvalueeventargs.md
Gets the current edit value.
Namespace : DevExpress.XtraEditors.Controls
Assembly : DevExpress.XtraEditors.v25.2.dll
NuGet Package : DevExpress.Win.Navigation
public object Value { get; }
Public ReadOnly Property Value As Object
| Type | Description |
|---|---|
| Object |
A Object expression representing an editor’s edit value.
|
This example demonstrates how to handle RepositoryItemCheckEdit.QueryCheckStateByValue and RepositoryItemCheckEdit.QueryValueByCheckState events in order to use a check editor to display and modify data from the bound data field.
The example assumes that a check editor is bound to a specific dataset field whose type is not obviously known and should be determined programmatically. The available data types that the field can take on are boolean, string and integer. So the field can contain the following combinations representing an option value (these values will be used to set the editor’s CheckEdit.EditValue property):
It is evident that making use of RepositoryItemCheckEdit.ValueChecked, RepositoryItemCheckEdit.ValueUnchecked and RepositoryItemCheckEdit.ValueGrayed properties is insufficient in this case. Thus, the example requires and implements a custom “edit value -> check state” and “check state -> edit value” conversion logic, which is illustrated by the sample code below.
using DevExpress.XtraEditors.Controls;
private void checkEdit1_QueryCheckStateByValue(object sender, QueryCheckStateByValueEventArgs e) {
string val = e.Value.ToString();
switch (val) {
case "True":
case "Yes":
case "1":
e.CheckState = CheckState.Checked;
break;
case "False":
case "No":
case "0":
e.CheckState = CheckState.Unchecked;
break;
default:
e.CheckState = CheckState.Indeterminate;
break;
}
e.Handled = true;
}
private void checkEdit1_QueryValueByCheckState(object sender, QueryValueByCheckStateEventArgs e) {
CheckEdit edit = sender as CheckEdit;
object val = edit.EditValue;
switch (e.CheckState) {
case CheckState.Checked:
if (val is bool) e.Value = true;
else if (val is string) e.Value = "Yes";
else if (val is int) e.Value = 1;
else e.Value = null;
break;
case CheckState.Unchecked:
if (val is bool) e.Value = false;
else if (val is string) e.Value = "No";
else if (val is int) e.Value = 0;
else e.Value = null;
break;
default:
if (val is bool) e.Value = false;
else if (val is string) e.Value = "?";
else if (val is int) e.Value = -1;
else e.Value = null;
break;
}
e.Handled = true;
}
Private Sub QueryCheckStateByValue(ByVal sender As Object, _
ByVal e As DevExpress.XtraEditors.Controls.QueryCheckStateByValueEventArgs)
Dim val As String = e.Value.ToString()
Select Case val
Case "True", "Yes", "1"
e.CheckState = CheckState.Checked
Case "False", "No", "0"
e.CheckState = CheckState.Unchecked
Case Else
e.CheckState = CheckState.Indeterminate
End Select
e.Handled = True
End Sub
Private Sub QueryValueByCheckState(ByVal sender As Object, _
ByVal e As DevExpress.XtraEditors.Controls.QueryValueByCheckStateEventArgs)
Dim Edit As CheckEdit = CType(sender, CheckEdit)
Dim Val As Object = Edit.EditValue
Select Case e.CheckState
Case CheckState.Checked
If TypeOf Val Is Boolean Then
e.Value = True
ElseIf TypeOf Val Is String Then
e.Value = "Yes"
ElseIf TypeOf Val Is Integer Then
e.Value = 1
Else : e.Value = Nothing
End If
Case CheckState.Unchecked
If TypeOf Val Is Boolean Then
e.Value = False
ElseIf TypeOf Val Is String Then
e.Value = "No"
ElseIf TypeOf Val Is Integer Then
e.Value = 0
Else : e.Value = Nothing
End If
Case Else
If TypeOf Val Is Boolean Then
e.Value = False
ElseIf TypeOf Val Is String Then
e.Value = "?"
ElseIf TypeOf Val Is Integer Then
e.Value = -1
Else : e.Value = Nothing
End If
End Select
e.Handled = True
End Sub
See Also
QueryCheckStateByValueEventArgs Class