Question

在C＃Windows窗体应用程序中;是否有一个ListView控件的事件处理程序，当项目添加到listview项时会被触发？

Answer 1

您无需编辑其他来源！

好的：从ListView更改为myListView

很久以前 - 但是我搜索没有带有自己的ItemAdd-Function的工具的解决方案！最好的方法...使用WndProc函数。

消息：LVM_INSERTITEM

http://msdn.microsoft.com/en-us/library/windows/desktop/bb761107%28v=vs.85%29.aspx

//COMMCTRL.H
#define LVM_FIRST               0x1000           // ListView messages
#define LVM_INSERTITEMA         (LVM_FIRST + 7)  
#define LVM_INSERTITEMW         (LVM_FIRST + 77) 
//edit itemremove (LVM_DELETEITEM)
#define LVM_DELETEITEM          (LVM_FIRST + 8)

C＃ - 实施

class myListView : ListView {

    protected override void WndProc(ref Message m){
        base.WndProc(ref m);

        switch (m.Msg){
            case 0x1007:    //ListViewItemAdd-A
                System.Diagnostics.Debug.WriteLine("Item added (A)");
                break;
            case 0x104D:    //ListViewItemAdd-W
                System.Diagnostics.Debug.WriteLine("Item added (W)");
                break;
            //edit for itemremove
            case 0x1008:
                System.Diagnostics.Debug.WriteLine("Item removed");
                break;
            case 0x1009:
                System.Diagnostics.Debug.WriteLine("Item removed (All)");
                break;
            default:
                break;
        }
    }
}

现在您可以激活自己的ItemAddedEvent。我希望能帮助其他有同样问题的人。

gegards raiserle

（编辑：请投票;））

Answer 2

我会see here 或here。它们或多或少是相同的答案，只是用不同的风格书写。简短版本，将ItemAdded事件添加到ListViewItemCollection。

Answer 3

没有事件可以做到这一点。但是你总是可以创建自己的列表框：

public class MyListView : ListView
{
    public void AddItem(ListViewItem item)
    {
        Items.Add(item);
        if (ItemAdded != null)
            ItemAdded.Invoke(this, new ItemsAddedArgs(item));
    }

    public EventHandler<ItemsAddedArgs> ItemAdded;
}

public class ItemsAddedArgs : EventArgs
{
    public ItemsAddedArgs(ListViewItem item)
    {
        Item = item;
    }

    public object Item { get; set; }
}

Answer 4

另一种方法是将项目保存在ObservableCollection类的实例中，将ListView.ItemsSource设置为该集合并订阅ObservableCollection.CollectionChanged事件。

Answer 5

框架不定义ItemAdded等事件。但是，请务必访问此解决方法：An Observer Pattern and an Extended ListView Event Model。例如，在那里定义了以下事件：

public event ListViewItemDelegate ItemAdded; 
public event ListViewItemRangeDelegate ItemRangeAdded; 
public event ListViewRemoveDelegate ItemRemoved; 
public event ListViewRemoveAtDelegate ItemRemovedAt;

Answer 6



    public class CustomListView : ListView
    {
        private const int LVM_FIRST = 0x1000;
        private const int LVM_INSERTITEMA = LVM_FIRST + 7;
        private const int LVM_INSERTITEMW = LVM_FIRST + 77;
        private const int LVM_DELETEITEM = LVM_FIRST + 8;
        private const int LVM_DELETEITEMALL = LVM_FIRST + 9;
    
        private CustomListViewItemOffsetSorter m_sorter;
    
        private System.ComponentModel.IContainer components = null;
        private System.Windows.Forms.Timer m_timer = null;
    
        public CustomListView()
            : base()
        {
            this.components = new System.ComponentModel.Container();
            this.m_timer = new Timer(this.components);
            this.m_timer.Interval = 1;
            this.m_timer.Tick += (s, e) =>
            {
                this.m_timer.Enabled = false;
                if (ItemCountChanged != null)
                {
                    ItemCountChanged.Invoke(this, EventArgs.Empty);
                }
            };
        }
    
        public event EventHandler ItemCountChanged;
    
        private void OnItemCountChanged()
        {
            this.m_timer.Enabled = false;
            this.m_timer.Enabled = true;
        }
    
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }
    
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);
    
            switch (m.Msg)
            {
                case LVM_INSERTITEMA:
                case LVM_INSERTITEMW:    //ListViewItemAdd-W
                case LVM_DELETEITEM:
                case LVM_DELETEITEMALL:
                    this.OnItemCountChanged();
                    break;
                default:
                    break;
            }
        }
    }



    //--------------------------------------------------------//
    CustomListView listView = new CustomListView();
    listView.ItemCountChanged += new EventHandler(listView_ItemCountChanged);
    
    private void listView_ItemCountChanged(object sender, EventArgs e)
    {
        System.Diagnostics.Debug.WriteLine("ItemCountChanged: {0}", listView.Items.Count);
    }

为ListView Items_added添加事件处理程序

6 个答案: