DataGridViewCheckBoxColumn.ThreeState 屬性

參考

定義

命名空間:: System.Windows.Forms

組件:: System.Windows.Forms.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

取得或設定值，指出裝載的核取方塊儲存格是否允許三種而非兩種核取狀態。

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

public bool ThreeState { get; set; }

member this.ThreeState : bool with get, set

Public Property ThreeState As Boolean

屬性值

Boolean

如果裝載的 DataGridViewCheckBoxCell 物件能夠擁有第三個不定狀態，則為 true，否則為 false。預設為 false。

例外狀況

InvalidOperationException

CellTemplate 屬性的值是 null。

範例

下列程式碼範例會使用 DataGridViewCheckBoxColumn 來追蹤辦公室光源的狀態。屬性會將 FalseValue 「turnedOff」與 false 產生關聯，屬性 TrueValue 會將「turnedOn」與 true 產生關聯，而屬性會將 IndeterminateValue 「unknown」關聯至不確定。

#using <System.Windows.Forms.dll>
#using <System.dll>
#using <System.Drawing.dll>
using namespace System;
using namespace System::IO;
using namespace System::Collections::Generic;
using namespace System::Windows::Forms;

public enum class LightStatus
{
    Unknown,
    TurnedOn,
    TurnedOff
};

public ref class TriValueVirtualCheckBox: public Form
{
private:
    DataGridView^ dataGridView1;

private:
    const int initialSize;

private:
    Dictionary<int, LightStatus>^ store;

public:
    TriValueVirtualCheckBox() :  Form(), initialSize(500)
    {
        dataGridView1 = gcnew DataGridView();
        store = gcnew Dictionary<int, LightStatus>();
        Text = this->GetType()->Name;

        for(int i = 0; i < initialSize; i++)
        {
            store->Add(i, LightStatus::Unknown);
        }

        Controls->Add(dataGridView1);
        dataGridView1->VirtualMode = true;
        dataGridView1->AllowUserToDeleteRows = false;
        dataGridView1->CellValueNeeded += 
            gcnew DataGridViewCellValueEventHandler(
            this, &TriValueVirtualCheckBox::dataGridView1_CellValueNeeded);
        dataGridView1->CellValuePushed += 
            gcnew DataGridViewCellValueEventHandler(
            this, &TriValueVirtualCheckBox::dataGridView1_CellValuePushed);

        dataGridView1->Columns->Add(CreateCheckBoxColumn());
        dataGridView1->Rows->AddCopies(0, initialSize);
    }

private:
    DataGridViewCheckBoxColumn^ CreateCheckBoxColumn()
    {
        DataGridViewCheckBoxColumn^ dataGridViewCheckBoxColumn1
            = gcnew DataGridViewCheckBoxColumn();
        dataGridViewCheckBoxColumn1->HeaderText = "Lights On";
        dataGridViewCheckBoxColumn1->TrueValue = LightStatus::TurnedOn;
        dataGridViewCheckBoxColumn1->FalseValue =
            LightStatus::TurnedOff;
        dataGridViewCheckBoxColumn1->IndeterminateValue
            = LightStatus::Unknown;
        dataGridViewCheckBoxColumn1->ThreeState = true;
        dataGridViewCheckBoxColumn1->ValueType = LightStatus::typeid;
        return dataGridViewCheckBoxColumn1;
    }

#pragma region "data store maintance"
private:
    void dataGridView1_CellValueNeeded(Object^ sender,
        DataGridViewCellValueEventArgs^ e)
    {
        e->Value = store[e->RowIndex];
    }

private:
    void dataGridView1_CellValuePushed(Object^ sender,
        DataGridViewCellValueEventArgs^ e)
    {
        store[e->RowIndex] = (LightStatus) e->Value;
    }
#pragma endregion

};

[STAThread]
int main()
{
    Application::Run(gcnew TriValueVirtualCheckBox());
}

using System;
using System.IO;
using System.Collections.Generic;
using System.Windows.Forms;

public class TriValueVirtualCheckBox:Form
{
    DataGridView dataGridView1 = new DataGridView();

    const int initialSize = 500;

    Dictionary<int, LightStatus> store 
        = new Dictionary<int, LightStatus>();

    public TriValueVirtualCheckBox() : base()
    {        
        Text = this.GetType().Name;

        int index = 0;
        for(index=0; index<=initialSize; index++)
            store.Add(index, LightStatus.Unknown);

        Controls.Add(dataGridView1);
        dataGridView1.VirtualMode = true;
        dataGridView1.AllowUserToDeleteRows = false;
        dataGridView1.CellValueNeeded += new 
            DataGridViewCellValueEventHandler(dataGridView1_CellValueNeeded);
        dataGridView1.CellValuePushed += new 
            DataGridViewCellValueEventHandler(dataGridView1_CellValuePushed);

        dataGridView1.Columns.Add(CreateCheckBoxColumn());
        dataGridView1.Rows.AddCopies(0, initialSize);
    }

    private DataGridViewCheckBoxColumn CreateCheckBoxColumn()
    {
        DataGridViewCheckBoxColumn dataGridViewCheckBoxColumn1 
            = new DataGridViewCheckBoxColumn();
        dataGridViewCheckBoxColumn1.HeaderText = "Lights On";
        dataGridViewCheckBoxColumn1.TrueValue = LightStatus.TurnedOn;
        dataGridViewCheckBoxColumn1.FalseValue = LightStatus.TurnedOff;
        dataGridViewCheckBoxColumn1.IndeterminateValue 
            = LightStatus.Unknown;
        dataGridViewCheckBoxColumn1.ThreeState = true;
        dataGridViewCheckBoxColumn1.ValueType = typeof(LightStatus);
        return dataGridViewCheckBoxColumn1;
    }

#region "data store maintance"
    private void dataGridView1_CellValueNeeded(object sender, 
        DataGridViewCellValueEventArgs e)
    {
        e.Value = store[e.RowIndex];
    }

    private void dataGridView1_CellValuePushed(object sender, 
        DataGridViewCellValueEventArgs e)
    {
        store[e.RowIndex] = (LightStatus) e.Value;
    }
#endregion

    [STAThreadAttribute()]
    public static void Main()
    {
        Application.Run(new TriValueVirtualCheckBox());
    }
}

public enum LightStatus
{
    Unknown, 
    TurnedOn, 
    TurnedOff
};

Imports System.IO
Imports System.Collections.Generic
Imports System.Windows.Forms

Public Class TriValueVirtualCheckBox
    Inherits System.Windows.Forms.Form

    Dim WithEvents dataGridView1 As New DataGridView

    Const initialSize As Integer = 500

    Dim store As New Dictionary(Of Integer, LightStatus)

    Public Sub New()
        MyBase.New()
        Text = Me.GetType().Name

        Dim index As Integer = 0
        For index = 0 To initialSize
            store.Add(index, LightStatus.Unknown)
        Next

        Controls.Add(dataGridView1)
        dataGridView1.VirtualMode = True
        dataGridView1.AllowUserToDeleteRows = False
        dataGridView1.Columns.Add(CreateCheckBoxColumn())
        dataGridView1.Rows.AddCopies(0, initialSize)
    End Sub

    Private Function CreateCheckBoxColumn() As DataGridViewCheckBoxColumn
        Dim dataGridViewCheckBoxColumn1 _
            As New DataGridViewCheckBoxColumn()
        dataGridViewCheckBoxColumn1.HeaderText = "Lights On"
        dataGridViewCheckBoxColumn1.TrueValue = LightStatus.TurnedOn
        dataGridViewCheckBoxColumn1.FalseValue = LightStatus.TurnedOff
        dataGridViewCheckBoxColumn1.IndeterminateValue = _
            LightStatus.Unknown
        dataGridViewCheckBoxColumn1.ThreeState = True
        dataGridViewCheckBoxColumn1.ValueType = GetType(LightStatus)
        Return dataGridViewCheckBoxColumn1
    End Function

#Region "data store maintance"
    Private Sub dataGridView1_CellValueNeeded(ByVal sender As Object, _
        ByVal e As DataGridViewCellValueEventArgs) _
        Handles dataGridView1.CellValueNeeded

        e.Value = store(e.RowIndex)
    End Sub

    Private Sub dataGridView1_CellValuePushed(ByVal sender As Object, _
        ByVal e As DataGridViewCellValueEventArgs) _
        Handles dataGridView1.CellValuePushed

        store.Item(e.RowIndex) = CType(e.Value, LightStatus)
    End Sub
#End Region

    <STAThreadAttribute()> _
    Public Shared Sub Main()
        Application.Run(New TriValueVirtualCheckBox())
    End Sub
End Class

Public Enum LightStatus
    Unknown
    TurnedOn
    TurnedOff
End Enum

備註

不確定狀態可能很有用，例如，當您不想在核取方塊中設定預設值時。

取得或設定這個屬性會取得或設定 ThreeState 屬性所 CellTemplate 傳回之儲存格物件的屬性。設定此屬性也會設定 ThreeState 資料行中每個儲存格的屬性，並重新整理資料行顯示。若要覆寫個別儲存格的指定值，請在設定資料行值之後設定儲存格值。

NullValue如果屬性所 DefaultCellStyle 傳回物件的屬性具有的值 false ，則變更 ThreeState 屬性值為自動設定 NullValue 為 true Indeterminate 。如果 NullValue 的值為 Indeterminate ，則將 ThreeState 屬性值變更為 false 自動設定 NullValue 為 false 。

適用於

共用方式為

DataGridViewCheckBoxColumn.ThreeState 屬性

定義

屬性值

例外狀況

範例

備註

適用於

另請參閱

其他資源