DataGridBoolColumn.NullValue Property

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

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Gets or sets the actual value used when setting the value of the column to Value.

public:
 property System::Object ^ NullValue { System::Object ^ get(); void set(System::Object ^ value); };

[System.ComponentModel.TypeConverter(typeof(System.ComponentModel.StringConverter))]
public object NullValue { get; set; }

[<System.ComponentModel.TypeConverter(typeof(System.ComponentModel.StringConverter))>]
member this.NullValue : obj with get, set

Public Property NullValue As Object

Property Value

Object

The value, typed as Object.

Attributes: TypeConverterAttribute

Examples

The following code example sets the TrueValue, FalseValue, and NullValue properties of a DataGridBoolColumn.

private:

   void SetBoolColumnValues()
   {
      DataGridBoolColumn^ myGridColumn;
      
      // Get the DataGridBoolColumn you are setting.
      myGridColumn = dynamic_cast<DataGridBoolColumn^>(myDataGrid->TableStyles[ "Customers" ]->GridColumnStyles[ "Current" ]);
      
      // Set TrueValue, FalseValue, and NullValue.
      myGridColumn->TrueValue = true;
      myGridColumn->FalseValue = false;
      myGridColumn->NullValue = Convert::DBNull;
   }

private void SetBoolColumnValues(){
   DataGridBoolColumn myGridColumn;
   // Get the DataGridBoolColumn you are setting.
   myGridColumn = (DataGridBoolColumn) myDataGrid.
   TableStyles["Customers"].GridColumnStyles["Current"];
   // Set TrueValue, FalseValue, and NullValue.
   myGridColumn.TrueValue = true;
   myGridColumn.FalseValue = false;
   myGridColumn.NullValue = Convert.DBNull;
}

Private Sub SetBoolColumnValues()
   Dim myGridColumn As DataGridBoolColumn 
   ' Get the DataGridBoolColumn you are setting.
   myGridColumn = CType(myDataGrid.TableStyles _
   ("Customers").GridColumnStyles("Current"), DataGridBoolColumn)
   ' Set TrueValue, FalseValue, and NullValue.
   myGridColumn.TrueValue = true
   myGridColumn.FalseValue = false
   myGridColumn.NullValue = Convert.DBNull
End Sub

Remarks

You can also specify what text will be displayed by setting the NullText property.

The AllowNull property must be set to true to enter null values.

The FalseValue, NullValue, and TrueValue properties determine the actual values pushed into the data source.

Applies to

Product	Versions
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop	3.0, 10

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