我有一个 ListView，checkboxes = true，View = List。在项目开始时，我进行了一些计算并确定数据库是否为空以及我应该从那里做什么。我要做的一件事是遍历报告名称的数组（来自 dll）并将列表视图项添加到 ListView，因为我们希望它尽可能动态。如果应用程序刚刚启动，则在 ListViewItem_ItemChecked 事件中（If Not _bShowAll Then）我只是让它通过，否则我称之为“昂贵”的功能。当我开始我的应用程序时，它似乎需要很长时间，所以我在“昂贵”函数中设置了一个断点，它被击中的次数与报告名称的次数一样多。我知道 ListViewItem.SelectedItem 如果设置将调用 ListViewItem_ItemChecked 以及 ListViewItem.Checked，我认为还有其他一些。但从初始化开始，我为 ListViewItem 调用的唯一函数是插入。当我在我的 ListViedItem_ItemChecked 中放置一个断点时，我命中了断点。这是我的构造函数、ListViewItem_ItemChecked 和“昂贵”函数。
Public Sub New()
'Initializes all of the controls on the screen and their properties.'
InitializeComponent()
'Sets the variable to what the Window text is at Startup'
_strTitle = Me.Text
'ViewModes is a dll that contains Class ViewModes and a variable ViewModes.'
'Goes through the Dictionary(Of string, String) and adds all of the keys to the View Mode ComboBox.'
For Each kvp As KeyValuePair(Of String, String) In ViewModes.ViewModes.ViewModes
cmbViewMode.Items.Add(kvp.Key)
Next
'Sets the View Mode ComboBox to the first item that was added to it.'
cmbViewMode.SelectedIndex = 0
lblFigureTitle.Text = "ALL"
_bShowAll = True
For Each strReportName As String In _dataController.ReportNames
lvReports.Items.Insert(lvReports.Items.Count, strReportName)
Next
_bShowAll = False
'Check to see if the database has any information or not.'
If Not _dataController.DatabaseIsEmpty Then
'There''s no point in doing the stuff in this block if the database is Empty'
'Sets the lable next to "IPB:" to the IPB obtained from the first record of the .out file.'
lblIPBNumber.Text = _dataController.IPBNumber
'Adds the IPB Number to the Window text so if it is minimized and the user has multiple'
'instances of the app running, they can know which one is which by hovering over the bar in the Taskbar.'
Me.Text = _strTitle + " IPB: " + _dataController.IPBNumber
'This builds the TreeView with the Figure names.'
BuildFigureTree()
'This goes through the data in the database and builds the list of reports'
'BuildReports()'
End If
End Sub
Private Sub lvReports_ItemChecked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ItemCheckedEventArgs) Handles lvReports.ItemChecked
If Not e Is Nothing Then
If cbAllReports.Checked Then
If Not e.Item.Checked Then
cbAllReports.Checked = False
e.Item.Checked = True
End If
_lstReportFilter.Add(e.Item.Name)
Else
If e.Item.Checked Then
_lstReportFilter.Add(e.Item.Name)
cbTaggedRecords.Checked = False
Else
_lstReportFilter.Remove(e.Item.Name)
End If
End If
Else
For Each lvi As ListViewItem In lvReports.Items
lvi.Checked = False
Next
End If
For Each rr As ReportRecord In _lstReportRecords.Where(Function(rRecord As ReportRecord) _lstReportFilter.Contains(rRecord.Description))
_strReportFilter += If(String.IsNullOrEmpty(_strReportFilter) Or _strReportFilter = "-1", "", ",") + rr.PartID.ToString()
Next
If Not _bShowAll Then
FillDataGridView()
End If
End Sub
Private Sub FillDataGridView()
'Set the cursor to a wait cursor just in case it takes some time retrieving information from the db'
Me.Cursor = Cursors.WaitCursor
Try
'We always want to make sure both scroll bars are visible'
dgvParts.ScrollBars = ScrollBars.Both
Dim strFilter As String = String.Empty
'If there is a value in the Search TextBox, add it to the filter'
If Not String.IsNullOrEmpty(_strSearchFilter) Then
strFilter += If(String.IsNullOrEmpty(strFilter), " ", " and ") + _strSearchFilter
End If
'For us to filter on Figures, there has to be nodes in the tree.'
If tvFigures.Nodes.Count > 0 Then
'If the FigureTitle text equals "ALL" (set whenever a tree node is selected)'
'then we don''t need to set a filter for figure.'
If Not lblFigureTitle.Text = "ALL" Then
'cbCurrentFigure is naturally not checked. And we don''t want to filter on just that figure'
'if the user isn''t searching for something. So if there is a value in the search box and'
'cbCurrentFigure is checked, then we want to look at only the selected figure. However,'
'if the search box is empty and cbCurrentFigure is not checked, we also want to search'
'only on the selected figure.'
If (Not String.IsNullOrEmpty(_strSearchFilter) And cbCurrentFigure.Checked) Or (String.IsNullOrEmpty(_strSearchFilter) And Not cbCurrentFigure.Checked) Then
strFilter += If(String.IsNullOrEmpty(strFilter), " ", " and ") + Constants.TransformColumnOrHeaderName("Figure") + " = '" + tvFigures.SelectedNode.Name + "'"
End If
Else
strFilter += If(String.IsNullOrEmpty(strFilter), " ", " and ") + Constants.TransformColumnOrHeaderName("Figure") + " LIKE '%%' "
End If
End If
'A selection of an indenture level in the combo box means we need to add a filter. "ALL"'
'is not a selection and needs no filter.'
If Not cmbIndentureLevel.Text = "ALL" And Not String.IsNullOrEmpty(cmbIndentureLevel.Text) Then
strFilter += If(String.IsNullOrEmpty(strFilter), " ", " and ") + Constants.TransformColumnOrHeaderName("Indenture") + " = " + cmbIndentureLevel.Text
End If
'If the user has selected any of the reports in the list view, add those to the filter.'
If Not String.IsNullOrEmpty(_strReportFilter) Then
strFilter += If(String.IsNullOrEmpty(strFilter), " ", " and ") + " PART_ID IN (" + _strReportFilter + ")"
End If
'If there is no filter, then we don''t want to view anything.'
If Not String.IsNullOrEmpty(strFilter) Then
'If there are validation errors from importing the file, we want to display those errors and get out.'
If _lstValidationResults.Count > 0 Then
dgvParts.DataSource = _lstValidationResults
For Each col As DataGridViewColumn In dgvParts.Columns
col.DataPropertyName = "ErrorMessage"
col.Visible = True
col.SortMode = DataGridViewColumnSortMode.Programmatic
col.AutoSizeMode = DataGridViewAutoSizeColumnMode.ColumnHeader
Next
dgvParts.AutoResizeColumns()
Return
End If
Dim bSource As BindingSource = New BindingSource()
'We use the text from the View Mode combo box to look in a dictionary and obtain'
'the query needed for that view. We also send the filter so we get ONLY what we'
'need when we''re pulling the data, instead of pulling it all and then filtering.'
bSource.DataSource = _dataController.PopulateDataGrid(cmbViewMode.Text, strFilter).Tables(0)
dgvParts.DataSource = bSource
dgvParts.Columns(0).Visible = False
'The Description Column should only be 250 characters in size. If a description is longer'
'than that, they need to double click the cell and a message box will pop up.'
dgvParts.Columns("Description").Resizable = DataGridViewTriState.False
dgvParts.Columns("Description").Width = 750
For Each col As DataGridViewColumn In dgvParts.Columns
'Programmatic sorting means custom sorting. May be changed to automatic.'
col.SortMode = DataGridViewColumnSortMode.Programmatic
'Again, we don''t want to resize the description column, it should stay set.'
If Not col.Name = "Description" Then
dgvParts.AutoResizeColumn(col.Index)
End If
'Because the Tags column is only reported, we do not want them to change any values'
'in the column.'
If col.Name.ToUpper() = "TAGS" Then
col.ReadOnly = True
End If
Next
'Other row and cell properties.'
dgvParts.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.DisplayedCells
dgvParts.ShowCellToolTips = True
dgvParts.BorderStyle = BorderStyle.Fixed3D
End If
FormatCells()
'The information from here until the Catch statement goes through and counts how'
'many records for each report there are and to set those counts into the items'
'in the list view.'
Dim nTotalCount As Integer = 0
For Each lvi As ListViewItem In lvReports.Items
Dim nCount As Integer = _lstReportRecords.Where(Function(rr As ReportRecord) lvi.Text.Contains(rr.Description)).Count()
nTotalCount += nCount
lvi.Text = If(lvi.Text.Contains("("), lvi.Text.Substring(0, lvi.Text.IndexOf("(") + 1), lvi.Text.Trim() + " (") + nTotalCount.ToString() + ")"
Next
cbAllReports.Text = If(cbAllReports.Text.Contains("("), cbAllReports.Text.Substring(0, cbAllReports.Text.IndexOf("(") + 1), cbAllReports.Text + " (") + nTotalCount.ToString() + ")"
cbTaggedRecords.Text = If(cbTaggedRecords.Text.Contains("("), cbTaggedRecords.Text.Substring(0, cbTaggedRecords.Text.IndexOf("(") + 1), cbTaggedRecords.Text + " (") + _lstReportRecords.Where(Function(rr As ReportRecord) rr.Description.Contains("Tagged")).Count().ToString() + ")"
Catch ex As Exception
'An exception was thrown. Show it to the user so they can report it.'
MessageBox.Show(ex.Message)
End Try
'Change the cursor back to the default cursor'
Me.Cursor = Cursors.Default
End Sub
在将项目插入 ListView 和 False 之前，我确保 _bShowAll 为 True（意味着通过 ItemChecked 函数），但我仍然点击了 ItemChanged 函数。任何人都可以看到我缺少的东西，一种使它更容易的方法，或者有没有一种方法可以在不调用 ItemChecked 方法的情况下插入一个项目？谢谢。
更新：没关系，每个人。我发现这个说它在 CheckBoxes 属性设置为 true 时调用该方法。