Watermark in Windows Forms ComboBox (SfComboBox)

Null value

Watermark text can be shown in the SfComboBox control by setting the AllowNull property to true. If the value is null and the editor portion of the control is empty, the watermark will be displayed as text in the SfComboBox control. The default value of AllowNull is false.

sfComboBox1.AllowNull = true;
sfComboBox1.AllowNull = True

Watermark on the ComboTextBox

Appearance

Watermark text can be changed by setting value to the Watermark property. Watermark fore color can be changed by setting value to the WatermarkForeColor property. The default watermark text is None.

sfComboBox1.Watermark = "Choose a US State";
sfComboBox1.Style.EditorStyle.WatermarkForeColor = Color.Blue;
sfComboBox1.Watermark = "Choose a US State"
sfComboBox1.Style.EditorStyle.WatermarkForeColor = Color.Blue

Watermark text with different color