DataGridView.CellErrorTextNeeded DataGridView.CellErrorTextNeeded DataGridView.CellErrorTextNeeded DataGridView.CellErrorTextNeeded Event

정의

셀의 오류 텍스트가 필요할 때 발생합니다.Occurs when a cell's error text is needed.

public:
 event System::Windows::Forms::DataGridViewCellErrorTextNeededEventHandler ^ CellErrorTextNeeded;
public event System.Windows.Forms.DataGridViewCellErrorTextNeededEventHandler CellErrorTextNeeded;
member this.CellErrorTextNeeded : System.Windows.Forms.DataGridViewCellErrorTextNeededEventHandler 
Public Custom Event CellErrorTextNeeded As DataGridViewCellErrorTextNeededEventHandler 

예제

다음 코드 예제에는 행을 공유 하지 않도록 모든 공유 셀에 걸쳐 복제 하려면 셀 오류 없이 셀에 대 한 오류 메시지를 만드는 방법을 보여 줍니다.The following code example demonstrates how to create error messages for cells without unsharing rows or causing the cell error to be duplicated over all the shared cells.

ToolStripMenuItem^ wholeTable;
ToolStripMenuItem^ lookUp;
System::Windows::Forms::ContextMenuStrip^ strip;
String^ cellErrorText;

void dataGridView1_CellContextMenuStripNeeded( Object^ /*sender*/,
    DataGridViewCellContextMenuStripNeededEventArgs^ e )
{
    cellErrorText = String::Empty;
    if ( strip == nullptr )
    {
        strip = gcnew System::Windows::Forms::ContextMenuStrip;
        lookUp->Text = L"Look Up";
        wholeTable->Text = L"See Whole Table";
        strip->Items->Add( lookUp );
        strip->Items->Add( wholeTable );
    }

    e->ContextMenuStrip = strip;
}

void wholeTable_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
{
    dataGridView1->DataSource = Populate( L"Select * from employees", true );
}

DataGridViewCellEventArgs^ theCellImHoveringOver;
void dataGridView1_CellMouseEnter( Object^ /*sender*/, DataGridViewCellEventArgs^ e )
{
    theCellImHoveringOver = e;
}

DataGridViewCellEventArgs^ cellErrorLocation;
void lookUp_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
{
    try
    {
        dataGridView1->DataSource = Populate( String::Format( L"Select * from employees where {0} = '{1}'", dataGridView1->Columns[ theCellImHoveringOver->ColumnIndex ]->Name, dataGridView1->Rows[ theCellImHoveringOver->RowIndex ]->Cells[ theCellImHoveringOver->ColumnIndex ]->Value ), true );
    }
    catch ( ... ) 
    {
        cellErrorText = L"Can't look this cell up";
        cellErrorLocation = theCellImHoveringOver;
    }

}

void dataGridView1_CellErrorTextNeeded( Object^ /*sender*/, DataGridViewCellErrorTextNeededEventArgs^ e )
{
    if ( cellErrorLocation != nullptr )
    {
        if ( e->ColumnIndex == cellErrorLocation->ColumnIndex && e->RowIndex == cellErrorLocation->RowIndex )
        {
            e->ErrorText = cellErrorText;
        }
    }
}

DataTable^ Populate( String^ query, bool resetUnsharedCounter )
{
    if ( resetUnsharedCounter )
    {
        ResetCounter();
    }


    // Alter the data source as necessary
    SqlDataAdapter^ adapter = gcnew SqlDataAdapter( query,
        gcnew SqlConnection( L"Integrated Security=SSPI;Persist Security Info=False;"
        L"Initial Catalog=Northwind;Data Source= localhost" ) );
    DataTable^ table = gcnew DataTable;
    adapter->Fill( table );
    return table;
}

Label^ count;
int unsharedRowCounter;
void ResetCounter()
{
    unsharedRowCounter = 0;
    count->Text = unsharedRowCounter.ToString();
}
private ToolStripMenuItem wholeTable = new ToolStripMenuItem();
private ToolStripMenuItem lookUp = new ToolStripMenuItem();
private ContextMenuStrip strip;
private string cellErrorText;

private void dataGridView1_CellContextMenuStripNeeded(object sender,
    DataGridViewCellContextMenuStripNeededEventArgs e)
{
    cellErrorText = String.Empty;

    if (strip == null)
    {
        strip = new ContextMenuStrip();
        lookUp.Text = "Look Up";
        wholeTable.Text = "See Whole Table";
        strip.Items.Add(lookUp);
        strip.Items.Add(wholeTable);
    }
    e.ContextMenuStrip = strip;
}

private void wholeTable_Click(object sender, EventArgs e)
{
    dataGridView1.DataSource = Populate("Select * from employees", true);
}

private DataGridViewCellEventArgs theCellImHoveringOver;

private void dataGridView1_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
{
    theCellImHoveringOver = e;
}

private DataGridViewCellEventArgs cellErrorLocation;

private void lookUp_Click(object sender, EventArgs e)
{
    try
    {
        dataGridView1.DataSource = Populate("Select * from employees where " +
            dataGridView1.Columns[theCellImHoveringOver.ColumnIndex].Name + " = '" +
            dataGridView1.Rows[theCellImHoveringOver.RowIndex].
            Cells[theCellImHoveringOver.ColumnIndex].Value + "'",
            true);
    }
    catch (SqlException)
    {
        cellErrorText = "Can't look this cell up";
        cellErrorLocation = theCellImHoveringOver;
    }
}

private void dataGridView1_CellErrorTextNeeded(object sender,
    DataGridViewCellErrorTextNeededEventArgs e)
{
    if (cellErrorLocation != null)
    {
        if (e.ColumnIndex == cellErrorLocation.ColumnIndex &&
            e.RowIndex == cellErrorLocation.RowIndex)
        {
            e.ErrorText = cellErrorText;
        }
    }
}

private DataTable Populate(string query, bool resetUnsharedCounter)
{
    if (resetUnsharedCounter)
    {
        ResetCounter();
    }

    // Alter the data source as necessary
    SqlDataAdapter adapter = new SqlDataAdapter(query,
        new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;" +
        "Initial Catalog=Northwind;Data Source=localhost"));

    DataTable table = new DataTable();
    table.Locale = System.Globalization.CultureInfo.InvariantCulture;
    adapter.Fill(table);
    return table;
}

private Label count = new Label();
private int unsharedRowCounter;

private void ResetCounter()
{
    unsharedRowCounter = 0;
    count.Text = unsharedRowCounter.ToString();
}
Private WithEvents wholeTable As New ToolStripMenuItem()
Private WithEvents lookUp As New ToolStripMenuItem()
Private strip As ContextMenuStrip
Private cellErrorText As String

Private Sub dataGridView1_CellContextMenuStripNeeded(ByVal sender As Object, _
    ByVal e As DataGridViewCellContextMenuStripNeededEventArgs) _
    Handles dataGridView1.CellContextMenuStripNeeded

    cellErrorText = String.Empty

    If strip Is Nothing Then
        strip = New ContextMenuStrip()
        lookUp.Text = "Look Up"
        wholeTable.Text = "See Whole Table"
        strip.Items.Add(lookUp)
        strip.Items.Add(wholeTable)
    End If
    e.ContextMenuStrip = strip
End Sub

Private Sub wholeTable_Click(ByVal sender As Object, ByVal e As EventArgs) Handles wholeTable.Click
    dataGridView1.DataSource = Populate("Select * from employees", True)
End Sub

Private theCellImHoveringOver As DataGridViewCellEventArgs

Private Sub dataGridView1_CellMouseEnter(ByVal sender As Object, _
    ByVal e As DataGridViewCellEventArgs) _
    Handles dataGridView1.CellMouseEnter

    theCellImHoveringOver = e
End Sub

Private cellErrorLocation As DataGridViewCellEventArgs

Private Sub lookUp_Click(ByVal sender As Object, ByVal e As EventArgs) Handles lookUp.Click
    Try
        dataGridView1.DataSource = Populate("Select * from employees where " & _
            dataGridView1.Columns(theCellImHoveringOver.ColumnIndex).Name & " = '" & _
            dataGridView1.Rows(theCellImHoveringOver.RowIndex).Cells(theCellImHoveringOver.ColumnIndex).Value.ToString() & _
            "'", True)
    Catch ex As SqlException
        cellErrorText = "Can't look this cell up"
        cellErrorLocation = theCellImHoveringOver
    End Try
End Sub

Private Sub dataGridView1_CellErrorTextNeeded(ByVal sender As Object, _
            ByVal e As DataGridViewCellErrorTextNeededEventArgs) _
            Handles dataGridView1.CellErrorTextNeeded
    If (Not cellErrorLocation Is Nothing) Then
        If e.ColumnIndex = cellErrorLocation.ColumnIndex AndAlso _
            e.RowIndex = cellErrorLocation.RowIndex Then
            e.ErrorText = cellErrorText
        End If
    End If
End Sub

Private Function Populate(ByVal query As String, ByVal resetUnsharedCounter As Boolean) As DataTable

    If resetUnsharedCounter Then
        ResetCounter()
    End If

    ' Alter the data source as necessary
    Dim adapter As New SqlDataAdapter(query, _
        New SqlConnection("Integrated Security=SSPI;Persist Security Info=False;" & _
        "Initial Catalog=Northwind;Data Source=localhost"))

    Dim table As New DataTable()
    table.Locale = System.Globalization.CultureInfo.InvariantCulture
    adapter.Fill(table)
    Return table
End Function

Private count As New Label()
Private unsharedRowCounter As Integer

Private Sub ResetCounter()
    unsharedRowCounter = 0
    count.Text = unsharedRowCounter.ToString()
End Sub

설명

CellErrorTextNeeded 이벤트에만 발생 경우를 DataGridView 컨트롤 DataSource 속성을 설정 또는 해당 VirtualMode 속성은 true합니다.The CellErrorTextNeeded event occurs only when the DataGridView control DataSource property is set or its VirtualMode property is true. 처리는 CellErrorTextNeeded 이벤트는 해당 값 또는 상태에 따라 셀에 대 한 오류를 확인 하려는 경우에 유용 합니다.Handling the CellErrorTextNeeded event is useful when you want to determine the error for a cell depending on its value or state.

처리 하는 경우는 CellErrorTextNeeded 이벤트 오류 텍스트에에서 지정 된 처리기를 오류 문자 모양과 셀에 표시 하지 않는 한는 ShowCellErrors 속성이 false 셀이 편집 모드 또는 합니다.When you handle the CellErrorTextNeeded event and specify error text in the handler, an error glyph appears in the cell unless the ShowCellErrors property is set to false or the cell is in edit mode. 오류 기호 위로 마우스 포인터를 이동할 때 오류 텍스트 도구 설명에 나타납니다.When the user moves the mouse pointer over the error glyph, the error text appears in a ToolTip.

CellErrorTextNeeded 이벤트도 발생 될 때마다 값을 DataGridViewCell.ErrorText 속성을 검색 합니다.The CellErrorTextNeeded event also occurs whenever the value of the DataGridViewCell.ErrorText property is retrieved.

사용할 수는 DataGridViewCellEventArgs.RowIndexColumnIndex 속성을 상태 또는 셀의 값을 확인 하 고이 정보를 사용 하 여 변경 하거나 수정 하는 DataGridViewCellErrorTextNeededEventArgs.ErrorText 속성입니다.You can use the DataGridViewCellEventArgs.RowIndex and ColumnIndex property to determine the state or value of a cell, and use this information to change or modify the DataGridViewCellErrorTextNeededEventArgs.ErrorText property. 이 속성은 셀의 값을 사용 하 여 초기화 ErrorText 이벤트 값을 재정의 하는 속성입니다.This property is initialized with the value of the cell ErrorText property, which the event value overrides.

처리를 CellErrorTextNeeded 많은 양의 데이터로 작업할 때 이벤트 ErrorText 여러 셀에 대 한 값입니다.Handle the CellErrorTextNeeded event when working with large amounts of data to avoid the performance penalties of setting the cell ErrorText value for multiple cells. 자세한 내용은 Windows Forms DataGridView 컨트롤의 크기 조정에 대 한 모범 사례합니다.For more information, see Best Practices for Scaling the Windows Forms DataGridView Control.

이벤트를 처리 하는 방법에 대 한 자세한 내용은 참조 하세요. 이벤트 처리 및 발생합니다.For more information about how to handle events, see Handling and Raising Events.

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