ItemCheckEventArgs 类

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

Source:

ItemCheckEventArgs.cs

为 ItemCheck 和 CheckedListBox 控件的 ListView 事件提供数据。

C#

public class ItemCheckEventArgs : EventArgs

继承

Object

EventArgs

ItemCheckEventArgs

示例

下面的代码示例演示了一个用于处理 事件的选中 ListView 控件 ListView.ItemCheck 。 方法使用 CurrentValue 对象的 和 Index 属性 ItemCheckEventArgs 来检索和计算所选菜单项的价格。 若要运行此示例，请将以下代码粘贴到包含 ListView 名为 ListView1 和 TextBox 的 Textbox1窗体中。 InitializeListView从窗体的构造函数或Load方法调用 方法。 确保所有事件都与其事件处理方法相关联。

C#

private void InitializeListView()
{
    this.ListView1 = new System.Windows.Forms.ListView();

    // Set properties such as BackColor and DockStyle and Location.
    this.ListView1.BackColor = System.Drawing.SystemColors.Control;
    this.ListView1.Dock = System.Windows.Forms.DockStyle.Top;
    this.ListView1.Location = new System.Drawing.Point(0, 0);
    this.ListView1.Size = new System.Drawing.Size(292, 130);
    this.ListView1.View = System.Windows.Forms.View.Details;
    this.ListView1.HideSelection = false;

    // Allow the user to select multiple items.
    this.ListView1.MultiSelect = true;

    // Show CheckBoxes in the ListView.
    this.ListView1.CheckBoxes = true;
    
    //Set the column headers and populate the columns.
    ListView1.HeaderStyle = ColumnHeaderStyle.Nonclickable;
    
    ColumnHeader columnHeader1 = new ColumnHeader();
    columnHeader1.Text = "Breakfast Choices";
    columnHeader1.TextAlign = HorizontalAlignment.Left;
    columnHeader1.Width = 146;

    ColumnHeader columnHeader2 = new ColumnHeader();
    columnHeader2.Text = "Price Each";
    columnHeader2.TextAlign = HorizontalAlignment.Center;
    columnHeader2.Width = 142;

    this.ListView1.Columns.Add(columnHeader1);
    this.ListView1.Columns.Add(columnHeader2);

    string[] foodList = new string[]{"Juice", "Coffee", 
        "Cereal & Milk", "Fruit Plate", "Toast & Jelly", 
        "Bagel & Cream Cheese"};

    string[] foodPrice = new string[]{"1.09", "1.09", "2.19", 
        "2.79", "2.09", "2.69"};
    
    int count;

    // Members are added one at a time, so call BeginUpdate to ensure 
    // the list is painted only once, rather than as each list item is added.
    ListView1.BeginUpdate();

    for(count = 0; count < foodList.Length; count++)
    {
        ListViewItem listItem = new ListViewItem(foodList[count]);
        listItem.SubItems.Add(foodPrice[count]);
        ListView1.Items.Add(listItem);
    }

    //Call EndUpdate when you finish adding items to the ListView.
    ListView1.EndUpdate();
    this.Controls.Add(this.ListView1);
}

C#

double price = 0.0;

// Handles the ItemCheck event. The method uses the CurrentValue
// property of the ItemCheckEventArgs to retrieve and tally the  
// price of the menu items selected.  
private void ListView1_ItemCheck1(object sender, 
    System.Windows.Forms.ItemCheckEventArgs e)
{
    if (e.CurrentValue==CheckState.Unchecked)
    {
        price += Double.Parse(
            this.ListView1.Items[e.Index].SubItems[1].Text);
    }
    else if((e.CurrentValue==CheckState.Checked))
    {
        price -= Double.Parse(
            this.ListView1.Items[e.Index].SubItems[1].Text);
    }

    // Output the price to TextBox1.
    TextBox1.Text = price.ToString();
}

注解

当 ItemCheck 选中列表框中项的选中状态发生更改时，将发生该事件。 类ItemCheckEventArgs指定要更改的项的索引、项检查框的当前值以及要为检查框设置的新值。

有关处理事件的详细信息，请参阅 处理和引发事件。

构造函数

ItemCheckEventArgs(Int32, CheckState, CheckState)

初始化 ItemCheckEventArgs 类的新实例。

属性

CurrentValue	获取一个值，该值指示该项的复选框的当前状态。
Index	获取要更改的项的从零开始的索引。
NewValue	获取或设置一个值，该值指示是否将该项的复选框设置为选中、未选中或不确定。

适用于

另请参阅

• CheckedListBox
• ItemCheck