UpDownBase.ReadOnly 属性

定义

获取或设置一个值,该值指示是否只能使用向上或向下按钮更改文本。Gets or sets a value indicating whether the text can be changed by the use of the up or down buttons only.

public:
 property bool ReadOnly { bool get(); void set(bool value); };
public bool ReadOnly { get; set; }
member this.ReadOnly : bool with get, set
Public Property ReadOnly As Boolean

属性值

如果只能使用向上或向下按钮更改文本,则为 true;否则为 falsetrue if the text can be changed by the use of the up or down buttons only; otherwise, false. 默认值是 falseThe default value is false.

示例

下面的代码示例使用派生类 NumericUpDown 并设置派生自 UpDownBase的部分属性。The following code example uses the derived class NumericUpDown and sets some of its properties derived from UpDownBase. 此代码要求在窗体上创建 NumericUpDown 控件、两个 ComboBox 控件和三个 CheckBox 控件。This code requires that you have a NumericUpDown control, two ComboBox controls, and three CheckBox controls created on a form. ComboBox 控件标记 BorderStyleTextAlignLabel the ComboBox controls BorderStyle and TextAlign. CheckBox 控件标记 InterceptArrowKeysReadOnlyUpDownAlignLabel the CheckBox controls InterceptArrowKeys, ReadOnly, and UpDownAlign. 代码允许您在运行时更改属性值,并查看每个属性值如何影响数字显示框的外观和行为。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. 将以下项添加到标记为 BorderStyle: NoneFixed3DFixedSingle的组合框。Add the following items to the combo box labeled BorderStyle: None, Fixed3D, and FixedSingle. 将以下项添加到标记为 "文本对齐: LeftRightCenter的组合框。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;
   }
}
private void comboBox1_SelectedIndexChanged(Object sender, 
                                             EventArgs e)
 {
      // Set the BorderStyle property.
     switch(comboBox1.Text)
     {
         case "Fixed3D":
             numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
             break;
         case "None":
             numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.None;
             break;
         case "FixedSingle":
             numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
             break;
     }
 }
 
 private void comboBox2_SelectedIndexChanged(Object sender, 
                                             EventArgs e)
 {
      // Set the TextAlign property.    
     switch (comboBox2.Text)
     {
         case "Right":
             numericUpDown1.TextAlign = HorizontalAlignment.Right;
             break;
         case "Left":
             numericUpDown1.TextAlign = HorizontalAlignment.Left;
             break;
         case "Center":
             numericUpDown1.TextAlign = HorizontalAlignment.Center;
             break;
     }
 }
 
 private void checkBox1_Click(Object sender, 
                              EventArgs e)
 {
      // Evaluate and toggle the ReadOnly property.
     if (numericUpDown1.ReadOnly)
     {
         numericUpDown1.ReadOnly = false;
     }
     else
     {
         numericUpDown1.ReadOnly = true;
     }
 }
 
 private void checkBox2_Click(Object sender, 
                              EventArgs e)
 {
      // Evaluate and toggle the InterceptArrowKeys property.
     if (numericUpDown1.InterceptArrowKeys)
     {  
         numericUpDown1.InterceptArrowKeys = false;
     }
     else
     {
         numericUpDown1.InterceptArrowKeys = true;
     }
 }
 
 private 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;
     }
 }
 
Private Sub comboBox1_SelectedIndexChanged(sender As Object, e As EventArgs)
    ' Set the BorderStyle property.
    Select Case comboBox1.Text
        Case "Fixed3D"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Case "None"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.None
        Case "FixedSingle"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
    End Select
End Sub    

Private Sub comboBox2_SelectedIndexChanged(sender As Object, e As EventArgs)
    ' Set the TextAlign property.    
    Select Case comboBox2.Text
        Case "Right"
            numericUpDown1.TextAlign = HorizontalAlignment.Right
        Case "Left"
            numericUpDown1.TextAlign = HorizontalAlignment.Left
        Case "Center"
            numericUpDown1.TextAlign = HorizontalAlignment.Center
    End Select
End Sub    

Private Sub checkBox1_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the ReadOnly property.
    If numericUpDown1.ReadOnly Then
        numericUpDown1.ReadOnly = False
    Else
        numericUpDown1.ReadOnly = True
    End If
End Sub    

Private Sub checkBox2_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the InterceptArrowKeys property.
    If numericUpDown1.InterceptArrowKeys Then
        numericUpDown1.InterceptArrowKeys = False
    Else
        numericUpDown1.InterceptArrowKeys = True
    End If
End Sub    

Private Sub checkBox3_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the UpDownAlign property.
    If numericUpDown1.UpDownAlign = LeftRightAlignment.Left Then
        numericUpDown1.UpDownAlign = LeftRightAlignment.Right
    Else
        numericUpDown1.UpDownAlign = LeftRightAlignment.Left
    End If
End Sub

注解

通过将 ReadOnly 属性设置为 true,无需对 Text 属性进行大量验证。By setting the ReadOnly property to true, you will eliminate the need for much validation of the Text property. 用户将被限制为使用 "上移" 和 "下移" 按钮更改 Text 值。The user will be restricted to the use of the up and down buttons to change the Text values. 它将只允许他们选择指定的值。It will only allow them to select values you specify.

备注

在派生类 DomainUpDown中,描述的行为稍有不同。In the derived class DomainUpDown, the behavior described is slightly different. ReadOnly 设置为 true 并按下某个键时,控件将选择集合中第一个字符与按下的键匹配的第一项。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.

适用于

另请参阅