如何从ListView控件中的各个项目中删除复选框？

Question

我有一个列表'Name'，'Expected'，'Total'的ListView，我想在最后添加另一个列'Recount'。只有当“预期”值大于“总计”值时，“重新计数”列才会有一个复选框。

到目前为止，我已经获得了包含列的ListView，并且可以在左侧添加一个复选框，但该复选框不在列标题下（尽管我可能会在其中放置另一个没有值的列来解决这是所有的记录。

任何人都有什么想法我还能做什么？

Answer 1

这实际上相对简单，只要您愿意忍受P / Invoke的苦差事来访问本机Windows控件中内置的功能，但.NET FW不会公开。

我演示in my answer here如何使用TreeView控件完成同样的事情，并考虑到ListView与TreeView的相似之处，这可以在非常相同的情况下完成使用ListView的方式。

以下是所有必需的代码（确保您为Imports命名空间添加了System.Runtime.InteropServices声明：

' P/Invoke declarations
Private Const LVIF_STATE As Integer = &H8
Private Const LVIS_STATEIMAGEMASK As Integer = &HF000
Private Const LVM_FIRST As Integer = &H1000
Private Const LVM_SETITEM As Integer = LVM_FIRST + 76

<StructLayout(LayoutKind.Sequential, Pack:=8, CharSet:=CharSet.Auto)> _
Private Structure LVITEM
   Public mask As Integer
   Public iItem As Integer
   Public iSubItem As Integer
   Public state As Integer
   Public stateMask As Integer
   <MarshalAs(UnmanagedType.LPTStr)> _
   Public lpszText As String
   Public cchTextMax As Integer
   Public iImage As Integer
   Public lParam As IntPtr
End Structure

<DllImport("user32.dll", CharSet:=CharSet.Auto)> _
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByRef lParam As LVITEM) As IntPtr
End Function

''' <summary>
''' Hides the checkbox for the specified item in a ListView control.
''' </summary>
Private Sub HideCheckBox(ByVal lvw As ListView, ByVal item As ListViewItem)
   Dim lvi As LVITEM = New LVITEM()
   lvi.iItem = item.Index
   lvi.mask = LVIF_STATE
   lvi.stateMask = LVIS_STATEIMAGEMASK
   lvi.state = 0
   SendMessage(lvw.Handle, LVM_SETITEM, IntPtr.Zero, lvi)
End Sub

然后你可以简单地调用上面的方法：

Private Sub btnHideCheckForSelected_Click(ByVal sender As Object, ByVal e As EventArgs)
   ' Hide the checkbox next to the currently selected ListViewItem
   HideCheckBox(myListView, myListView.SelectedItems(0))
End Sub

制作看起来有点像这样的东西（点击番茄和黄瓜项目的“隐藏检查”按钮后）：

Answer 2

下面的C＃版本。

    private void HideCheckbox(ListView lvw, ListViewItem item)
    {
        var lviItem = new LVITEM();
        lviItem.iItem = item.Index;
        lviItem.mask = LVIF_STATE;
        lviItem.stateMask = LVIS_STATEIMAGEMASK;
        lviItem.state = 0;
        SendMessage(lvw.Handle, LVM_SETITEM, IntPtr.Zero, ref lviItem);
    }

    private const int LVIF_STATE = 0x8;
    private const int LVIS_STATEIMAGEMASK = 0xF000;
    private const int LVM_FIRST = 0x1000;
    private const int LVM_SETITEM = LVM_FIRST + 76;

    // suppress warnings for interop
#pragma warning disable 0649
    private struct LVITEM
    {
        public int mask;
        public int iItem;
        public int iSubItem;
        public int state;
        public int stateMask;
        [MarshalAs(UnmanagedType.LPTStr)]
        public String lpszText;
        public int cchTextMax;
        public int iImage;
        public IntPtr iParam;
    }
#pragma warning restore 0649

    [DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam,  ref LVITEM lParam);

    private void button1_Click(object sender, EventArgs e)
    {
        HideCheckbox(listView1, listView1.SelectedItems[0]);
    }