UpDownBase::ReadOnly Property

 

Gets or sets a value indicating whether the text can be changed by the use of the up or down buttons only.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public:
property bool ReadOnly {
	bool get();
	void set(bool value);
}

Property Value

Type: System::Boolean

true if the text can be changed by the use of the up or down buttons only; otherwise, false. The default value is false.

By setting the ReadOnly property to true, you will eliminate the need for much validation of the Text property. The user will be restricted to the use of the up and down buttons to change the Text values. It will only allow them to select values you specify.

System_CAPS_noteNote

In the derived class DomainUpDown, the behavior described is slightly different. When ReadOnly is set to true and a key is pressed, the control selects the first item in the collection where the first character matches the key pressed.

The following code example uses the derived class NumericUpDown and sets some of its properties derived from UpDownBase. This code requires that you have a NumericUpDown control, two ComboBox controls, and three CheckBox controls created on a form. Label the ComboBox controls BorderStyle and TextAlign. Label the CheckBox controls InterceptArrowKeys, ReadOnly, and UpDownAlign. The code allows you to change the property values at run time and see how each affects the appearance and behavior of the spin box. Add the following items to the combo box labeled BorderStyle: None, Fixed3D, and FixedSingle. Add the following items to the combo box labeled TextAlign: Left, Right, and Center.

void comboBox1_SelectedIndexChanged( Object^ sender, EventArgs^ e )
{
   // Set the BorderStyle property.
   if (  !String::Compare( comboBox1->Text, "Fixed3D" ) )
   {
      numericUpDown1->BorderStyle = System::Windows::Forms::BorderStyle::Fixed3D;
   }
   else
   if (  !String::Compare( comboBox1->Text, "None" ) )
   {
      numericUpDown1->BorderStyle = System::Windows::Forms::BorderStyle::None;
   }
   else
   if (  !String::Compare( comboBox1->Text, "FixedSingle" ) )
   {
      numericUpDown1->BorderStyle = System::Windows::Forms::BorderStyle::FixedSingle;
   }
}

void comboBox2_SelectedIndexChanged( Object^ sender, EventArgs^ e )
{
   // Set the TextAlign property.    
   if (  !String::Compare( comboBox2->Text, "Right" ) )
   {
      numericUpDown1->TextAlign = HorizontalAlignment::Right;
   }
   else
   if (  !String::Compare( comboBox1->Text, "Left" ) )
   {
      numericUpDown1->TextAlign = HorizontalAlignment::Left;
   }
   else
   if (  !String::Compare( comboBox1->Text, "Center" ) )
   {
      numericUpDown1->TextAlign = HorizontalAlignment::Center;
   }
}

void checkBox1_Click( Object^ sender, EventArgs^ e )
{
   // Evaluate and toggle the ReadOnly property.
   if ( numericUpDown1->ReadOnly )
   {
      numericUpDown1->ReadOnly = false;
   }
   else
   {
      numericUpDown1->ReadOnly = true;
   }
}

void checkBox2_Click( Object^ sender, EventArgs^ e )
{
   // Evaluate and toggle the InterceptArrowKeys property.
   if ( numericUpDown1->InterceptArrowKeys )
   {
      numericUpDown1->InterceptArrowKeys = false;
   }
   else
   {
      numericUpDown1->InterceptArrowKeys = true;
   }
}

void checkBox3_Click( Object^ sender, EventArgs^ e )
{
   // Evaluate and toggle the UpDownAlign property.
   if ( numericUpDown1->UpDownAlign == LeftRightAlignment::Left )
   {
      numericUpDown1->UpDownAlign = LeftRightAlignment::Right;
   }
   else
   {
      numericUpDown1->UpDownAlign = LeftRightAlignment::Left;
   }
}

.NET Framework
Available since 1.1
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