DataGridView.CellFormatting DataGridView.CellFormatting DataGridView.CellFormatting DataGridView.CellFormatting Event

定义

需要设置单元格内容的显示格式时发生。Occurs when the contents of a cell need to be formatted for display.

public:
 event System::Windows::Forms::DataGridViewCellFormattingEventHandler ^ CellFormatting;
public event System.Windows.Forms.DataGridViewCellFormattingEventHandler CellFormatting;
member this.CellFormatting : System.Windows.Forms.DataGridViewCellFormattingEventHandler 
Public Custom Event CellFormatting As DataGridViewCellFormattingEventHandler 

示例

下面的代码示例演示如何处理CellFormatting事件。The following code example shows how to handle the CellFormatting event.

void dataGridView1_CellFormatting( Object^ /*sender*/, DataGridViewCellFormattingEventArgs^ e )
{
   // If the column is the Artist column, check the
   // value.
   if ( this->dataGridView1->Columns[ e->ColumnIndex ]->Name->Equals( "Artist" ) )
   {
      if ( e->Value != nullptr )
      {
         // Check for the string "pink" in the cell.
         String^ stringValue = dynamic_cast<String^>(e->Value);
         stringValue = stringValue->ToLower();
         if ( (stringValue->IndexOf( "pink" ) > -1) )
         {
            DataGridViewCellStyle^ pinkStyle = gcnew DataGridViewCellStyle;

            //Change the style of the cell.
            pinkStyle->BackColor = Color::Pink;
            pinkStyle->ForeColor = Color::Black;
            pinkStyle->Font = gcnew System::Drawing::Font( "Times New Roman",8,FontStyle::Bold );
            e->CellStyle = pinkStyle;
         }
         
      }
   }
   else
   if ( this->dataGridView1->Columns[ e->ColumnIndex ]->Name->Equals( "Release Date" ) )
   {
      ShortFormDateFormat( e );
   }
}


//Even though the date internaly stores the year as YYYY, using formatting, the
//UI can have the format in YY.  
void ShortFormDateFormat( DataGridViewCellFormattingEventArgs^ formatting )
{
   if ( formatting->Value != nullptr )
   {
      try
      {
         System::Text::StringBuilder^ dateString = gcnew System::Text::StringBuilder;
         DateTime theDate = DateTime::Parse( formatting->Value->ToString() );
         dateString->Append( theDate.Month );
         dateString->Append( "/" );
         dateString->Append( theDate.Day );
         dateString->Append( "/" );
         dateString->Append( theDate.Year.ToString()->Substring( 2 ) );
         formatting->Value = dateString->ToString();
         formatting->FormattingApplied = true;
      }
      catch ( Exception^ /*notInDateFormat*/ ) 
      {
         // Set to false in case there are other handlers interested trying to
         // format this DataGridViewCellFormattingEventArgs instance.
         formatting->FormattingApplied = false;
      }

   }
}
private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
    // If the column is the Artist column, check the
    // value.
    if (this.dataGridView1.Columns[e.ColumnIndex].Name == "Artist")
    {
        if (e.Value != null)
        {
            // Check for the string "pink" in the cell.
            string stringValue = (string)e.Value;
            stringValue = stringValue.ToLower();
            if ((stringValue.IndexOf("pink") > -1))
            {
                e.CellStyle.BackColor = Color.Pink;
            }

        }
    }
    else if (this.dataGridView1.Columns[e.ColumnIndex].Name == "Release Date")
    {
        ShortFormDateFormat(e);
    }
}

//Even though the date internaly stores the year as YYYY, using formatting, the
//UI can have the format in YY.  
private static void ShortFormDateFormat(DataGridViewCellFormattingEventArgs formatting)
{
    if (formatting.Value != null)
    {
        try
        {
            System.Text.StringBuilder dateString = new System.Text.StringBuilder();
            DateTime theDate = DateTime.Parse(formatting.Value.ToString());

            dateString.Append(theDate.Month);
            dateString.Append("/");
            dateString.Append(theDate.Day);
            dateString.Append("/");
            dateString.Append(theDate.Year.ToString().Substring(2));
            formatting.Value = dateString.ToString();
            formatting.FormattingApplied = true;
        }
        catch (FormatException)
        {
            // Set to false in case there are other handlers interested trying to
            // format this DataGridViewCellFormattingEventArgs instance.
            formatting.FormattingApplied = false;
        }
    }
}
Private Sub dataGridView1_CellFormatting(ByVal sender As Object, _
    ByVal e As DataGridViewCellFormattingEventArgs) _
    Handles dataGridView1.CellFormatting
    ' If the column is the Artist column, check the
    ' value.
    If Me.dataGridView1.Columns(e.ColumnIndex).Name _
        = "Artist" Then
        If e.Value IsNot Nothing Then

            ' Check for the string "pink" in the cell.
            Dim stringValue As String = _
            CType(e.Value, String)
            stringValue = stringValue.ToLower()
            If ((stringValue.IndexOf("pink") > -1)) Then
                e.CellStyle.BackColor = Color.Pink
            End If

        End If
    ElseIf Me.dataGridView1.Columns(e.ColumnIndex).Name _
        = "Release Date" Then
        ShortFormDateFormat(e)
    End If
End Sub

'Even though the date internaly stores the year as YYYY, using formatting, the
'UI can have the format in YY.  
Private Shared Sub ShortFormDateFormat(ByVal formatting As DataGridViewCellFormattingEventArgs)
    If formatting.Value IsNot Nothing Then
        Try
            Dim dateString As System.Text.StringBuilder = New System.Text.StringBuilder()
            Dim theDate As Date = DateTime.Parse(formatting.Value.ToString())

            dateString.Append(theDate.Month)
            dateString.Append("/")
            dateString.Append(theDate.Day)
            dateString.Append("/")
            dateString.Append(theDate.Year.ToString().Substring(2))
            formatting.Value = dateString.ToString()
            formatting.FormattingApplied = True
        Catch notInDateFormat As FormatException
            ' Set to false in case there are other handlers interested trying to
            ' format this DataGridViewCellFormattingEventArgs instance.
            formatting.FormattingApplied = False
        End Try
    End If
End Sub

注解

默认情况下,DataGridView控件将尝试将单元格的值转换为适合显示格式。By default, the DataGridView control will attempt to convert a cell's value into a format suitable for display. 例如,它将转换为数字值的文本框单元中显示的字符串。For example, it will convert a numerical value into a string for display in a text box cell. 可以通过设置使用的格式设置约定来指示Format的属性DataGridViewCellStyle属性返回如DefaultCellStyle属性。You can indicate the formatting convention to use by setting the Format property of the DataGridViewCellStyle returned by properties such as the DefaultCellStyle property.

如果标准的格式设置是不够的可以自定义格式设置通过处理CellFormatting事件。If the standard formatting is insufficient, you can customize the formatting by handling the CellFormatting event. 此事件可以指示具体的显示值,以及单元格样式,如前景色和背景颜色,若要使用的单元格显示。This event lets you indicate the exact display value as well as the cell styles, such as background and foreground color, to use for the cell display. 这意味着可以处理任何类型的单元格格式,而不考虑是否单元格的值本身需要格式设置此事件。This means you can handle this event for any kind of cell formatting, regardless of whether the cell value itself needs formatting.

CellFormatting每次每个单元格绘制,因此,应避免耗时处理在处理此事件时发生的事件。The CellFormatting event occurs every time each cell is painted, so you should avoid lengthy processing when handling this event. 也会发生此事件时该单元格FormattedValue检索或其GetFormattedValue调用方法。This event also occurs when the cell FormattedValue is retrieved or its GetFormattedValue method is called.

当处理CellFormatting事件,ConvertEventArgs.Value与单元格的值初始化属性。When you handle the CellFormatting event, the ConvertEventArgs.Value property is initialized with the cell value. 如果提供从单元格的值的显示值的自定义转换,设置ConvertEventArgs.Value属性设置为转换后的值,确保新的值指定单元格的类型的FormattedValueType属性。If you provide custom conversion from the cell value to the display value, set the ConvertEventArgs.Value property to the converted value, ensuring that the new value is of the type specified by the cell FormattedValueType property. 若要指示没有更多值的格式设置是有必要,设置DataGridViewCellFormattingEventArgs.FormattingApplied属性设置为trueTo indicate that no further value formatting is necessary, set the DataGridViewCellFormattingEventArgs.FormattingApplied property to true.

事件处理程序完成后,如果ConvertEventArgs.Valuenull或者不是正确的类型,或DataGridViewCellFormattingEventArgs.FormattingApplied属性是false,则Value使用格式化FormatNullValueDataSourceNullValue,和FormatProvider属性返回的单元格样式DataGridViewCellFormattingEventArgs.CellStyle属性,则使用该单元格初始化InheritedStyle属性。When the event handler completes, if the ConvertEventArgs.Value is null or is not of the correct type, or the DataGridViewCellFormattingEventArgs.FormattingApplied property is false, the Value is formatted using the Format, NullValue, DataSourceNullValue, and FormatProvider properties of the cell style returned by the DataGridViewCellFormattingEventArgs.CellStyle property, which is initialized using the cell InheritedStyle property.

而不考虑的值DataGridViewCellFormattingEventArgs.FormattingApplied属性中,返回的对象的显示属性DataGridViewCellFormattingEventArgs.CellStyle属性用于呈现该单元格。Regardless of the value of the DataGridViewCellFormattingEventArgs.FormattingApplied property, the display properties of the object returned by the DataGridViewCellFormattingEventArgs.CellStyle property are used to render the cell.

有关自定义格式设置使用的详细信息CellFormatting事件,请参阅如何:自定义 Windows 窗体 DataGridView 控件中的数据格式设置For more information about custom formatting using the CellFormatting event, see How to: Customize Data Formatting in the Windows Forms DataGridView Control.

若要避免处理此事件时出现的性能损失,通过参数的事件处理程序,而不是直接访问该单元格访问该单元格。To avoid performance penalties when handling this event, access the cell through the parameters of the event handler rather than accessing the cell directly.

若要自定义一个带格式的用户指定值转换为实际的单元值,请处理CellParsing事件。To customize the conversion of a formatted, user-specified value into an actual cell value, handle the CellParsing event.

有关如何处理事件的详细信息,请参阅处理和引发事件For more information about how to handle events, see Handling and Raising Events.

适用于

另请参阅