Winform下的Datagrid的列风格(5)—DataGridTreeViewColumn
class DataGridTreeViewColumn: DataGridColumnStyle 
{
private TreeView myTreeView = new TreeView (); private DataView ChoiceDataViewSource; private string ChoiceDisplayField; private string ChoiceValueField; private string ChoiceParentValueField; private bool isEditing; public DataGridTreeViewColumn(DataView ChoiceDataViewSource,string ChoiceDisplayField,string ChoiceValueField) : base() 
{//适用于主键策略采用System.Guid 类型的表，其他类型不可能不适用，需要修改
this.ChoiceDataViewSource =ChoiceDataViewSource; this.ChoiceDisplayField =ChoiceDisplayField; char[] bytearray_临时=new char[] {' '}; string[] stringarrya_临时=ChoiceValueField.Split (bytearray_临时); this.ChoiceValueField =stringarrya_临时[0]; this.ChoiceParentValueField=stringarrya_临时[1]; //myComboBox.DropDownStyle =System.Windows .Forms .ComboBoxStyle .DropDownList ; myTreeView.Visible = false; //myComboBox.DataSource =this.ChoiceDataViewSource; //myComboBox.DisplayMember= this.ChoiceDisplayField; //myComboBox.ValueMember =this.ChoiceValueField;
} protected override void Abort(int rowNum) { isEditing = false; myTreeView.AfterSelect -=new System.Windows .Forms .TreeViewEventHandler (TreeViewSelectedIndexChanged); //myComboBox.SelectedIndexChanged -= // new EventHandler(ComboBoxSelectedIndexChanged ); Invalidate(); } protected override bool Commit (CurrencyManager dataSource, int rowNum) { myTreeView.Bounds =Rectangle.Empty; //myComboBox.Bounds = Rectangle.Empty; myTreeView.AfterSelect -=new System.Windows.Forms .TreeViewEventHandler (TreeViewSelectedIndexChanged); //myComboBox.SelectedIndexChanged -= // new EventHandler(ComboBoxSelectedIndexChanged ); if (!isEditing) return true; isEditing = false; try { System.Object value = myTreeView.SelectedNode.Tag ;//.SelectedValue; SetColumnValueAtRow(dataSource, rowNum, value); } catch (Exception) { Abort(rowNum); return false; } Invalidate(); return true; } protected override void Edit( CurrencyManager source, int rowNum, Rectangle bounds, bool readOnly, string instantText, bool cellIsVisible) { TreeView_Creator(); object value =GetColumnValueAtRow(source, rowNum); if (cellIsVisible) { int h=200; if (bounds.Height<25) h=bounds.Height *8; if (bounds.Y >h) { myTreeView.Bounds = new Rectangle (bounds.X + 2, bounds.Y+bounds.Height - 2-h, bounds.Width - 4, h); } else { myTreeView.Bounds = new Rectangle (bounds.X + 2, bounds.Y + 2, bounds.Width - 4, h); } System.Windows .Forms .TreeNode i= FindTree (value); if (i!=null) { myTreeView.SelectedNode =i; } myTreeView.Visible = true; myTreeView.AfterSelect += new System.Windows .Forms .TreeViewEventHandler (TreeViewSelectedIndexChanged ); } else { //myComboBox.Value = value;需要增加一段程序，查对对应显示项显示 myTreeView.SelectedNode =this.FindTree (value); myTreeView.Visible = false; } if (myTreeView.Visible) DataGridTableStyle.DataGrid.Invalidate(bounds); } private void TreeView_Creator() { this.myTreeView .Nodes .Clear (); System.Windows .Forms .TreeNode snode; string stemp=ChoiceDataViewSource.RowFilter ; int t=ChoiceDataViewSource.Count ;//Test ChoiceDataViewSource.RowFilter =ChoiceParentValueField+"='00000000-0000-0000-0000-000000000000'"; int int1=ChoiceDataViewSource.Count ; string[] Displays=new string [int1]; object[] Values=new object [int1]; for (int i=0;i<int1;i++) { Displays[i]= ChoiceDataViewSource[i][ChoiceDisplayField].ToString (); Values[i]=ChoiceDataViewSource[i][ChoiceValueField]; } for (int i=0;i<int1;i++) { snode=new TreeNode (); snode.Text =Displays[i]; snode.Tag =Values[i]; ChoiceDataViewSource.RowFilter =ChoiceParentValueField+"='"+Values[i].ToString ()+"'"; if (ChoiceDataViewSource.Count >0) { snode.Nodes .AddRange (CreatSubNodes()); } myTreeView.Nodes .Add (snode); } ChoiceDataViewSource.RowFilter=stemp; } private System.Windows .Forms .TreeNode[] CreatSubNodes() { System.Windows .Forms .TreeNode[] snodes=null; string stemp=ChoiceDataViewSource.RowFilter ; int int1=ChoiceDataViewSource.Count ; string[] Displays=new string [int1]; object[] Values=new object [int1]; snodes=new System.Windows .Forms .TreeNode[int1]; for (int i=0;i<int1;i++) { Displays[i]= ChoiceDataViewSource[i][ChoiceDisplayField].ToString (); Values[i]=ChoiceDataViewSource[i][ChoiceValueField]; } for (int i=0;i<int1;i++) { snodes[i]=new TreeNode (); snodes[i].Text =Displays[i]; snodes[i].Tag =Values[i]; ChoiceDataViewSource.RowFilter =ChoiceParentValueField+"='"+Values[i].ToString ()+"'"; if (ChoiceDataViewSource.Count >0) { snodes[i].Nodes.AddRange (CreatSubNodes()); } //myTreeView.Nodes .Add (snode); } //ChoiceDataViewSource.RowFilter=stemp; return snodes; } protected int Find(System.Object value) { int int1; int int2; int2=ChoiceDataViewSource.Count ; if (int2<=0) { return -1; } for (int1=0;int1<int2;int1++) { if (ChoiceDataViewSource[int1][ChoiceValueField ].ToString ().Trim ()==value.ToString ().Trim ()) { return int1; } } return -1; } private System.Windows .Forms .TreeNode FindTreeNode(System.Object value,System.Windows .Forms .TreeNode SubNode) { int int1;int int2; System.Windows .Forms .TreeNode node1; //System.Windows .Forms .TreeNode [] nodearray; //nodearray=SubNode.Nodes ; int2=SubNode.Nodes.Count ; if (int2<=0) { return null; } for (int1=0;int1<int2;int1++) { if (SubNode.Nodes[int1].Tag .ToString ().Trim ()==value.ToString ().Trim ()) { return SubNode.Nodes[int1]; } if (SubNode.Nodes[int1].Nodes .Count >0) { node1=FindTreeNode(value,SubNode.Nodes[int1]); if (node1!=null) { return node1; } } } return null; } protected System.Windows .Forms .TreeNode FindTree(System.Object value) { System.Windows .Forms .TreeNode snode; int int1=this.myTreeView .Nodes .Count ; for (int i=0;i<int1;i++) { snode=FindTreeNode(value,this.myTreeView .Nodes [i]); if (snode!=null) { return snode; } } return null; } protected override Size GetPreferredSize( Graphics g, object value) { return new Size(100, 25);//myComboBox.PreferredHeight+ 4); } protected override int GetMinimumHeight() { return 25;//this.myTreeView.hei.PreferredHeight + 4; } protected override int GetPreferredHeight(Graphics g, object value) { return 25;//return myComboBox.PreferredHeight + 4; } protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum) { Paint(g, bounds, source, rowNum, false); } protected override void Paint( Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, bool alignToRight) { Paint( g,bounds, source, rowNum, Brushes.Red, Brushes.Blue, alignToRight); } protected override void Paint( Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, Brush backBrush, Brush foreBrush, bool alignToRight) { object value=GetColumnValueAtRow(source, rowNum); int int1=Find (value); string display=""; if (int1>=0) { display=this.ChoiceDataViewSource [int1][ChoiceDisplayField ].ToString (); } Rectangle rect = bounds; g.FillRectangle(backBrush,rect); rect.Offset(0, 2); rect.Height -= 2; g.DrawString(display, this.DataGridTableStyle.DataGrid.Font, foreBrush, rect); } protected override void SetDataGridInColumn(DataGrid value) { base.SetDataGridInColumn(value); if (myTreeView.Parent != null) { myTreeView.Parent .Controls .Remove (myTreeView); } if (value != null) { value.Controls.Add(myTreeView); } } private void TreeViewSelectedIndexChanged(object sender, System.Windows .Forms .TreeViewEventArgs e) { this.isEditing = true; base.ColumnStartedEditing(myTreeView); }
}例：学生档案 班级档案 年极档案 学校档案
则当datagrid显示学生档案时，他的学生属班级ID_Point列点击后显示“学校-年级-班级”树视，可以从中选择班级，焦点离开后显示班级名称。
还有一效率问题，因每次点击DataGridTreeViewColumn列中的单元格都根据dataview重新生成treeview，再根据当前单元格的ID_Point查找到树视中的选择项，当dataview稍大一点时，可明显感觉到延时。
暂时使用吧，以后想到更好的办法再改进。
