DataGridView.CellToolTipTextNeeded 事件

public:
 event System::Windows::Forms::DataGridViewCellToolTipTextNeededEventHandler ^ CellToolTipTextNeeded;

public event System.Windows.Forms.DataGridViewCellToolTipTextNeededEventHandler CellToolTipTextNeeded;

public event System.Windows.Forms.DataGridViewCellToolTipTextNeededEventHandler? CellToolTipTextNeeded;

member this.CellToolTipTextNeeded : System.Windows.Forms.DataGridViewCellToolTipTextNeededEventHandler 

Public Custom Event CellToolTipTextNeeded As DataGridViewCellToolTipTextNeededEventHandler 

事件類型

範例

下列程式代碼範例示範如何使用 CellToolTipTextNeeded 事件處理程式，在數據綁定 DataGridView 控件中顯示隱藏數據行的資訊。

void dataGridView1_CellToolTipTextNeeded(object sender,
    DataGridViewCellToolTipTextNeededEventArgs e)
{
    string newLine = Environment.NewLine;
    if (e.RowIndex > -1)
    {
        DataGridViewRow dataGridViewRow1 = dataGridView1.Rows[e.RowIndex];

        // Add the employee's ID to the ToolTipText.
        e.ToolTipText = String.Format("EmployeeID {0}:{1}",
            dataGridViewRow1.Cells["EmployeeID"].Value, newLine);

        // Add the employee's name to the ToolTipText.
        e.ToolTipText += String.Format("{0} {1} {2}{3}",
            dataGridViewRow1.Cells["TitleOfCourtesy"].Value.ToString(),
            dataGridViewRow1.Cells["FirstName"].Value.ToString(),
            dataGridViewRow1.Cells["LastName"].Value.ToString(),
            newLine);

        // Add the employee's title to the ToolTipText.
        e.ToolTipText += String.Format("{0}{1}{2}",
            dataGridViewRow1.Cells["Title"].Value.ToString(),
            newLine, newLine);

        // Add the employee's contact information to the ToolTipText.
        e.ToolTipText += String.Format("{0}{1}{2}, ",
            dataGridViewRow1.Cells["Address"].Value.ToString(), newLine,
            dataGridViewRow1.Cells["City"].Value.ToString());
        if (!String.IsNullOrEmpty(
            dataGridViewRow1.Cells["Region"].Value.ToString()))
        {
            e.ToolTipText += String.Format("{0}, ",
                dataGridViewRow1.Cells["Region"].Value.ToString());
        }
        e.ToolTipText += String.Format("{0}, {1}{2}{3} EXT:{4}{5}{6}",
            dataGridViewRow1.Cells["Country"].Value.ToString(),
            dataGridViewRow1.Cells["PostalCode"].Value.ToString(),
            newLine, dataGridViewRow1.Cells["HomePhone"].Value.ToString(),
            dataGridViewRow1.Cells["Extension"].Value.ToString(),
            newLine, newLine);

        // Add employee information to the ToolTipText.
        DateTime HireDate =
            (DateTime)dataGridViewRow1.Cells["HireDate"].Value;
        e.ToolTipText +=
            String.Format("Employee since: {0}/{1}/{2}{3}Manager: {4}",
            HireDate.Month.ToString(), HireDate.Day.ToString(),
            HireDate.Year.ToString(), newLine,
            dataGridViewRow1.Cells["Manager"].Value.ToString());
    }
}

Public Sub dataGridView1_CellToolTipTextNeeded(ByVal sender As Object, _
    ByVal e As DataGridViewCellToolTipTextNeededEventArgs) _
    Handles dataGridView1.CellToolTipTextNeeded

    Dim newLine As String = Environment.NewLine
    If e.RowIndex > -1 Then
        Dim dataGridViewRow1 As DataGridViewRow = _
        dataGridView1.Rows(e.RowIndex)

        ' Add the employee's ID to the ToolTipText.
        e.ToolTipText = String.Format("EmployeeID {0}: {1}", _
            dataGridViewRow1.Cells("EmployeeID").Value.ToString(), _
            newLine)

        ' Add the employee's name to the ToolTipText.
        e.ToolTipText += String.Format("{0} {1} {2} {3}", _
            dataGridViewRow1.Cells("TitleOfCourtesy").Value.ToString(), _
            dataGridViewRow1.Cells("FirstName").Value.ToString(), _
            dataGridViewRow1.Cells("LastName").Value.ToString(), _
            newLine)

        ' Add the employee's title to the ToolTipText.
        e.ToolTipText += String.Format("{0}{1}{2}", _
            dataGridViewRow1.Cells("Title").Value.ToString(), _
            newLine, newLine)

        ' Add the employee's contact information to the ToolTipText.
        e.ToolTipText += String.Format("{0}{1}{2}, ", _
            dataGridViewRow1.Cells("Address").Value.ToString(), newLine, _
            dataGridViewRow1.Cells("City").Value.ToString())
        If Not String.IsNullOrEmpty( _
            dataGridViewRow1.Cells("Region").Value.ToString())

            e.ToolTipText += String.Format("{0}, ", _
               dataGridViewRow1.Cells("Region").Value.ToString())
        End If
        e.ToolTipText += String.Format("{0}, {1}{2}{3} EXT:{4}{5}{6}", _
            dataGridViewRow1.Cells("Country").Value.ToString(), _
            dataGridViewRow1.Cells("PostalCode").Value.ToString(), _
            newLine, _
            dataGridViewRow1.Cells("HomePhone").Value.ToString(), _
            dataGridViewRow1.Cells("Extension").Value.ToString(), _
            newLine, newLine)

        ' Add employee information to the ToolTipText.
        Dim HireDate As DateTime = _
            CType(dataGridViewRow1.Cells("HireDate").Value, DateTime)
        e.ToolTipText += _
            String.Format("Employee since: {0}/{1}/{2}{3}Manager: {4}", _
                HireDate.Month.ToString(), HireDate.Day.ToString(), _
                HireDate.Year.ToString(), newLine, _
                dataGridViewRow1.Cells("Manager").Value.ToString())
    End If
End Sub

備註

CellToolTipTextNeeded只有在設定控件DataSource屬性或其 VirtualMode 屬性為 true時，DataGridView才會發生此事件。

當您處理 CellToolTipTextNeeded 事件時，如果 ShowCellToolTips 屬性值是 true ，而且滑鼠指標位於單元格上方，或使用者使用鍵盤流覽至單元格，就會顯示您在處理程式中指定的ToolTip文字。 當您想要顯示數據格目前狀態或值所決定的工具提示時，事件 CellToolTipTextNeeded 會很有用。

CellToolTipTextNeeded每當以程式設計方式擷取屬性的值DataGridViewCell.ToolTipText，或當使用者使用滑鼠或鍵盤流覽至單元格時，也會發生此事件。

您可以使用 DataGridViewCellEventArgs.ColumnIndex 和 RowIndex 屬性來判斷儲存格的狀態或值，並使用這項資訊來變更或修改 DataGridViewCellToolTipTextNeededEventArgs.ToolTipText 屬性。 這個屬性會使用事件值所覆寫的單元格 ToolTipText 屬性值初始化。

CellToolTipTextNeeded處理大量數據時，請處理 事件，以避免設定多個數據格ToolTipText值的效能負面影響。 如需詳細資訊，請參閱 縮放 Windows Form DataGridView 控制項的最佳做法。

如需如何處理事件的詳細資訊，請參閱 處理和引發事件。

適用於

另請參閱

• DataSource
• VirtualMode
• ShowCellToolTips
• DataGridViewCellToolTipTextNeededEventHandler
• DataGridViewCellToolTipTextNeededEventArgs
• ToolTipText
• ToolTipText
• OnCellToolTipTextNeeded(DataGridViewCellToolTipTextNeededEventArgs)
• DataGridView 控制項 (Windows Form)