Uso de la fuente de datos con CheckBoxList

Question

Uso CheckBoxList en mi aplicación Windows Forms y estoy tratando de aplicarle una fuente de datos.

Tener un DataTable, 'dt', con columnas id, name y ischecked, utilizo dicho código:

((ListBox)MyCheckBoxList).DataSource = dt; 
((ListBox)MyCheckBoxList).DisplayMember = "name"; 
((ListBox)MyCheckBoxList).ValueMember = "id"; 

¿Cómo se configura CheckState para todos los artículos en MyCheckBoxList?

Guardo este valor en mi datatable y quiero vincularlos con MyCheckBoxList.

Answer 1

No estoy seguro de que haya una forma de establecer el cheque a través de la propiedad ValueMember.

Se podría dar a este un ir:

foreach (DataRow item in dt.Rows) 
{ 
    MyCheckedListBox.Items.Add(item["Name"].ToString(), Convert.ToBoolean(item["Checked"])); 
} 

Answer 2

he decidido mi problema en dos etapas. En primer lugar, he aplicado la fuente de datos, y luego en el círculo establecer la propiedad activada para cada artículo, como en el siguiente código:

((ListBox)MyCheckBoxList).DataSource = dt; 
((ListBox)MyCheckBoxList).DisplayMember = "name"; 
        ... 

for (int i = 0; i < folloving.Items.Count; i++) 
{ 
    DataRowView row = (DataRowView)MyCheckBoxList.Items[i]; 
    bool isChecked = Convert.ToBoolean(row["checked"]); 
    MyCheckBoxList.SetItemChecked(i, isChecked); 
} 

Answer 3

Como otra solución alternativa, he implementado el evento CheckedListBox.Format para actualizar automáticamente el CheckedState visualizado con los datos; e implementó el evento CheckedListBox.ItemCheck para actualizar automáticamente los datos con CheckedState.

private DataTable myDataTable = null; 
private BindingSource myBindingSource = new BindingSource(); 

// Column Name Constants 
private const string C_ITEM_INDEX = "Item_Index";  // CheckedListBox Item's Index 
private const string C_ITEM_TEXT = "Item_Text";  // Item's Text 
private const string C_ITEM_CHECKED = "Item_Checked"; // Item's Checked State 
private const string C_DATA_KEY = "Data_Key";   // Arbitrary Key Value for Relating Item to Other Data 

private void Startup() 
{ 
    // Create DataTable 
    // This DataTable has 4 Columns described by the constants above 
    myDataTable = new DataTable(); 
    myDataTable.Columns.Add(new DataColumn(C_ITEM_INDEX, typeof(Int32))); 
    myDataTable.Columns[C_ITEM_INDEX].DefaultValue = 0; 
    myDataTable.Columns.Add(new DataColumn(C_ITEM_TEXT, typeof(string))); 
    myDataTable.Columns[C_ITEM_TEXT].DefaultValue = ""; 

    // I personally like Integer 1=true, 0=false values. typeof(bool) will also work. 
    myDataTable.Columns.Add(new DataColumn(C_ITEM_CHECKED, typeof(Int32))); 
    myDataTable.Columns[C_ITEM_CHECKED].DefaultValue = 0; 

    // Other columns can be included in the DataTable 
    myDataTable.Columns.Add(new DataColumn(C_DATA_KEY, typeof(Int32))); 
    myDataTable.Columns[C_DATA_KEY].DefaultValue = 0;  
    myDataTable.AcceptChanges(); 

    // Bind the DataTable's DefaultView to the CheckedListBox 
    myBindingSource.DataSource = myDataTable.DefaultView; 
    this.myCheckedListBox.DataSource = myBindingSource; 

    // Set the DisplayMember to the DataColumn you want displayed as the CheckedListBox Items's Text 
    this.myCheckedListBox.DisplayMember = C_ITEM_TEXT; 

    // Set the ValueMember to the Data. Note: The ValueMember is not displayed and is Not the CheckBox value. 
    this.myCheckedListBox.ValueMember = C_DATA_KEY; 

    // Hookup Event Handler for the CheckedListBox.Format Event. 
    /// * The Format event enables us to just in time update the CheckBoxes with the values in the DataTable 
    this.myCheckedListBox.Format += myCheckedListBox_Format; 

    // Hookup Event Handler for the CheckedListBox.ItemCheck Event. 
    /// * The ItemCheck event enables us to just in time update the DataTable with the values from the Item CheckBoxes 
    this.myCheckedListBox.ItemCheck += myCheckedListBox_ItemCheck; 
} 


void myCheckedListBox_Format(object sender, ListControlConvertEventArgs e) 
{ 
    /// * The Format event enables us to just in time update the CheckBoxes with the values in the DataTable 
    // Retrieve the Index of the Item in the CheckedListBox by finding the DataRowView in the BindingSource 
    // Note: Use a column with unique values for the BindingSource.Find() function 
    int listindex = myBindingSource.Find(C_ITEM_INDEX, ((DataRowView)e.ListItem)[C_ITEM_INDEX]); 

    // The argument, e.ListItem, is the current DataRowView in the DataTable's DefaultView 
    // Check to see if the checkbox value is different from the data 
    if (((CheckedListBox)sender).GetItemChecked(listindex) != Convert.ToBoolean(((DataRowView)e.ListItem)[C_ITEM_CHECKED])) 
    { 
    // Set the CheckList Item's CheckState to match the data 
    ((CheckedListBox)sender).SetItemChecked(listindex, Convert.ToBoolean(((DataRowView)e.ListItem)[C_ITEM_CHECKED])); 
    } 
} 


void myCheckedListBox_ItemCheck(object sender, ItemCheckEventArgs e) 
{ 
    /// * The ItemCheck event enables us to just in time update the DataTable with the values from the Item CheckBoxes 
    // Update the data with the new CheckState value. 
    if (e.NewValue == CheckState.Checked) 
    { 
    myDataTable.DefaultView[e.Index][C_ITEM_CHECKED] = 1; 
    } 
    else 
    { 
    myDataTable.DefaultView[e.Index][C_ITEM_CHECKED] = 0; 
    } 
    // Update other data values too if you need to. 
}