C#如何自定義DataGridViewColumn來顯示TreeView

2019-11-14 13:41:50

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　　我們可以自定義DataGridView的DataGridViewColumn來實現自定義的列，下面介紹一下如何通過擴展DataGridViewColumn來實現一個TreeViewColumn

1 TreeViewColumn類

　TreeViewColumn繼承自DataGridViewColumn，為了動態給TreeViewColumn傳入一個TreeView，這里暴露出一個公共屬性_root，可以綁定一個初始化的TreeView. 另外需要重寫DataGridCell類型的CellTemplate，這里返還一個TreeViewCell（需要自定義）

 1     /// <summary> 2     /// Host TreeView In DataGridView Cell 3     /// </summary> 4    public class TreeViewColumn : DataGridViewColumn 5     { 6         public TreeViewColumn() 7             : base(new TreeViewCell()) 8         { 9         }10         [Description("Set TreeView Root in DataGridView Cell"), Category("TreeView")]11         public TreeView _root12         {13             get{return Roots.tree;}14             set{Roots.tree=value;}15         }16         public override DataGridViewCell CellTemplate17         {18             get19             {20                 return base.CellTemplate;21             }22             set23             {24                 // Ensure that the cell used for the template is a TreeViewCell.25                 if (value != null &&26                     !value.GetType().IsAssignableFrom(typeof(TreeViewCell)))27                 {28                     throw new InvalidCastException("Must be a TreeViewCell");29                 }30                 base.CellTemplate = value;31             }32         }33     }

2 TreeViewCell類

　　上面TreeViewColumn重寫了CellTemplate，返回的就是自定義的TreeViewCell，這里就是具體實現其邏輯。一般來說選擇樹控件的節點后，返回的是一個文本信息，是文本類型，可以繼承DataGridViewTextBoxCell,并重寫InitializeEditingControl來進行自定義的DataGridView.EditingControl （編輯控件）。

 1   public class TreeViewCell : DataGridViewTextBoxCell 2     { 3  4         public TreeViewCell() 5             : base() 6         { 7          8             //初始設置 9         }10        11         public override void InitializeEditingControl(int rowIndex, object12             initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)13         {14             // Set the value of the editing control to the current cell value.15             base.InitializeEditingControl(rowIndex, initialFormattedValue,16                 dataGridViewCellStyle);17             TreeViewEditingControl ctl =18                 DataGridView.EditingControl as TreeViewEditingControl;19             // Use the default row value when Value PRoperty is null.20             if (this.Value == null)21             {22 23                 ctl.SelectedNode =new TreeNode( this.DefaultNewRowValue.ToString());24             }25             else26             {27                 ctl.SelectedNode = new TreeNode(this.Value.ToString());28             }29         }30 31         public override Type EditType32         {33             get34             {35                 // Return the type of the editing control that CalendarCell uses.36                 return typeof(TreeViewEditingControl);37             }38         }39 40         public override Type ValueType41         {42             get43             {44                 // Return the type of the value that CalendarCell contains.45                 return typeof(String);46             }47         }48 49         public override object DefaultNewRowValue50         {51             get52             {53                 // Use the current date and time as the default value.54                 return "";55             }56         }57     }

3 TreeViewEditingControl類

　　TreeViewEditingControl為編輯控件，當用戶編輯TreeViewCell時，顯示的為樹編輯控件，需要繼承TreeView，同時實現IDataGridViewEditingControl接口，實現以下方法：

  1 public class TreeViewEditingControl : TreeView, IDataGridViewEditingControl  2     {  3         DataGridView dataGridView;  4         private bool valueChanged = false;  5         int rowIndex;  6         public TreeViewEditingControl()  7         {  8             try  9             { 10                 //必須加Roots.tree.Nodes[0].Clone() 否則報錯 不能在多處增添或插入項，必須首先將其從當前位置移除或將其克隆 11                 this.Nodes.Add(Roots.tree.Nodes[0].Clone() as TreeNode); 12                 this.SelectedNode = this.Nodes[0]; 13  14                15             } 16             catch (Exception ex) 17             { 18                 MessageBox.Show(ex.Message); 19             } 20             21           22         } 23     24         // Implements the IDataGridViewEditingControl.EditingControlFormattedValue  25         // property. 26         public object EditingControlFormattedValue 27         { 28             get 29             { 30                 return this.SelectedNode.Text; 31             } 32             set 33             { 34                 if (value is String) 35                 { 36                     try 37                     { 38                         // This will throw an exception of the string is  39                         // null, empty, or not in the format of a date. 40                         this.SelectedNode = new TreeNode((String)value); 41                          42                     } 43                     catch 44                     { 45                         // In the case of an exception, just use the  46                         // default value so we're not left with a null 47                         // value. 48                         this.SelectedNode = new TreeNode(""); 49                     } 50                 } 51             } 52         } 53  54         // Implements the  55         // IDataGridViewEditingControl.GetEditingControlFormattedValue method. 56         public object GetEditingControlFormattedValue( 57             DataGridViewDataErrorContexts context) 58         { 59             return EditingControlFormattedValue; 60         } 61  62         // Implements the  63         // IDataGridViewEditingControl.ApplyCellStyleToEditingControl method. 64         public void ApplyCellStyleToEditingControl( 65             DataGridViewCellStyle dataGridViewCellStyle) 66         { 67             this.Font = dataGridViewCellStyle.Font; 68             this.ForeColor = dataGridViewCellStyle.ForeColor; 69             this.BackColor = dataGridViewCellStyle.BackColor; 70         } 71  72         // Implements the IDataGridViewEditingControl.EditingControlRowIndex  73         // property. 74         public int EditingControlRowIndex 75         { 76             get 77             { 78                 return rowIndex; 79             } 80             set 81             { 82                 rowIndex = value; 83             } 84         } 85  86         // Implements the IDataGridViewEditingControl.EditingControlWantsInputKey  87         // method. 88         public bool EditingControlWantsInputKey( 89             Keys key, bool dataGridViewWantsInputKey) 90         { 91             // Let the TreeViewPicker handle the keys listed. 92             switch (key & Keys.KeyCode) 93             { 94                 case Keys.Left: 95                 case Keys.Up: 96                 case Keys.Down: 97                 case Keys.Right: 98                 case Keys.Home: 99                 case Keys.End:100                 case Keys.PageDown:101                 case Keys.PageUp:102                     return true;103                 default:104                     return !dataGridViewWantsInputKey;105             }106         }107 108         // Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit 109         // method.110         public void PrepareEditingControlForEdit(bool selectAll)111         {112             // No preparation needs to be done.113         }114 115         // Implements the IDataGridViewEditingControl116         // .RepositionEditingControlOnValueChange property.117         public bool RepositionEditingControlOnValueChange118         {119             get120             {121                 return false;122             }123         }124 125         // Implements the IDataGridViewEditingControl126         // .EditingControlDataGridView property.127         public DataGridView EditingControlDataGridView128         {129             get130             {131                 return dataGridView;132             }133             set134             {135                 dataGridView = value;136             }137         }138 139         // Implements the IDataGridViewEditingControl140         // .EditingControlValueChanged property.141         public bool EditingControlValueChanged142         {143             get144             {145                 return valueChanged;146             }147             set148             {149                 valueChanged = value;150             }151         }152 153         // Implements the IDataGridViewEditingControl154         // .EditingPanelCursor property.155         public Cursor EditingPanelCursor156         {157             get158             {159                 return base.Cursor;160             }161         }162 163         protected override void OnAfterExpand(TreeViewEventArgs e)164         {165             base.OnAfterExpand(e);166             this.dataGridView.Columns[this.dataGridView.CurrentCell.ColumnIndex].Width = this.Width+10;167             this.dataGridView.Rows[this.dataGridView.CurrentCell.RowIndex].Height = this.Height+20;168            169         }170         protected override void OnAfterSelect(TreeViewEventArgs e)171         {172             // Notify the DataGridView that the contents of the cell173             // have changed.174             valueChanged = true;175             this.EditingControlDataGridView.NotifyCurrentCellDirty(true);176             base.OnAfterSelect(e);177             178         }179        180     }

　　為了在不同類之間傳遞參數，定義一個全局靜態類：

1   /// <summary>2     /// 靜態類的靜態屬性，用于在不同class間傳遞參數3     /// </summary>4     public static class Roots5     {6         //從前臺綁定樹7        public static TreeView tree = null;8     }

完整代碼為：

  1 using System;  2 using System.Collections.Generic;  3 using System.Linq;  4 using System.Text;  5 using System.Windows.Forms;  6 using System.ComponentModel;  7 namespace Host_Controls_in_Windows_Forms_DataGridView_Cells  8 {  9     /// <summary> 10     /// 靜態類的靜態屬性，用于在不同class間傳遞參數 11     /// </summary> 12     public static class Roots 13     { 14         //從前臺綁定樹 15        public static TreeView tree = null; 16     } 17     /// <summary> 18     /// Host TreeView In DataGridView Cell 19     /// </summary> 20    public class TreeViewColumn : DataGridViewColumn 21     { 22         public TreeViewColumn() 23             : base(new TreeViewCell()) 24         { 25         } 26         [Description("Set TreeView Root in DataGridView Cell"), Category("TreeView")] 27         public TreeView _root 28         { 29             get{return Roots.tree;} 30             set{Roots.tree=value;} 31         } 32         public override DataGridViewCell CellTemplate 33         { 34             get 35             { 36                 return base.CellTemplate; 37             } 38             set 39             { 40                 // Ensure that the cell used for the template is a TreeViewCell. 41                 if (value != null && 42                     !value.GetType().IsAssignableFrom(typeof(TreeViewCell))) 43                 { 44                     throw new InvalidCastException("Must be a TreeViewCell"); 45                 } 46                 base.CellTemplate = value; 47             } 48         } 49     } 50  51     //---------------------------------------------------------------------- 52     public class TreeViewCell : DataGridViewTextBoxCell 53     { 54  55         public TreeViewCell() 56             : base() 57         { 58          59             //初始設置 60         } 61         62         public override void InitializeEditingControl(int rowIndex, object 63             initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle) 64         { 65             // Set the value of the editing control to the current cell value. 66             base.InitializeEditingControl(rowIndex, initialFormattedValue, 67                 dataGridViewCellStyle); 68             TreeViewEditingControl ctl = 69                 DataGridView.EditingControl as TreeViewEditingControl; 70             // Use the default row value when Value property is null. 71             if (this.Value == null) 72             { 73  74                 ctl.SelectedNode =new TreeNode( this.DefaultNewRowValue.ToString()); 75             } 76             else 77             { 78                 ctl.SelectedNode = new TreeNode(this.Value.ToString()); 79             } 80         } 81  82         public override Type EditType 83         { 84             get 85             { 86                 // Return the type of the editing control that CalendarCell uses. 87                 return typeof(TreeViewEditingControl); 88             } 89         } 90  91         public override Type ValueType 92         { 93             get 94             { 95                 // Return the type of the value that CalendarCell contains. 96                 return typeof(String); 97             } 98         } 99 100         public override object DefaultNewRowValue101         {102             get103             {104                 // Use the current date and time as the default value.105                 return "";106             }107         }108     }109     //-----------------------------------------------------------------110 111    public class TreeViewEditingControl : TreeView, IDataGridViewEditingControl112     {113         DataGridView dataGridView;114         private bool valueChanged = false;115         int rowIndex;116         public TreeViewEditingControl()117         {118             try119             {120                 //必須加Roots.tree.Nodes[0].Clone() 否則報錯 不能在多處增添或插入項，必須首先將其從當前位置移除或將其克隆121                 this.Nodes.Add(Roots.tree.Nodes[0].Clone() as TreeNode);122                 this.SelectedNode = this.Nodes[0];123 124               125             }126             catch (Exception ex)127             {128                 MessageBox.Show(ex.Message);129             }130            131          132         }133    134         // Implements the IDataGridViewEditingControl.EditingControlFormattedValue 135         // property.136         public object EditingControlFormattedValue137         {138             get139             {140                 return this.SelectedNode.Text;141             }142             set143             {144                 if (value is String)145                 {146                     try147                     {148                         // This will throw an exception of the string is 149                         // null, empty, or not in the format of a date.150                         this.SelectedNode = new TreeNode((String)value);151                         152                     }153                     catch154                     {155                         // In the case of an exception, just use the 156                         // default value so we're not left with a null157                         // value.158                         this.SelectedNode = new TreeNode("");159                     }160                 }161             }162         }163 164         // Implements the 165         // IDataGridViewEditingControl.GetEditingControlFormattedValue method.166         public object GetEditingControlFormattedValue(167             DataGridViewDataErrorContexts context)168         {169             return EditingControlFormattedValue;170         }171 172         // Implements the 173         // IDataGridViewEditingControl.ApplyCellStyleToEditingControl method.174         public void ApplyCellStyleToEditingControl(175             DataGridViewCellStyle dataGridViewCellStyle)176         {177             this.Font = dataGridViewCellStyle.Font;178             this.ForeColor = dataGridViewCellStyle.ForeColor;179             this.BackColor = dataGridViewCellStyle.BackColor;180         }181 182         // Implements the IDataGridViewEditingControl.EditingControlRowIndex 183         // property.184         public int EditingControlRowIndex185         {186             get187             {188                 return rowIndex;189             }190             set191             {192                 rowIndex = value;193             }194         }195 196         // Implements the IDataGridViewEditingControl.EditingControlWantsInputKey 197         // method.198         public bool EditingControlWantsInputKey(199             Keys key, bool dataGridViewWantsInputKey)200         {201             // Let the TreeViewPicker handle the keys listed.202             switch (key & Keys.KeyCode)203             {204                 case Keys.Left:205                 case Keys.Up:206                 case Keys.Down:207                 case Keys.Right:208                 case Keys.Home:209                 case Keys.End:210                 case Keys.PageDown:211                 case Keys.PageUp:212                     return true;213                 default:214                     return !dataGridViewWantsInputKey;215             }216         }217 218         // Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit 219         // method.220         public void PrepareEditingControlForEdit(bool selectAll)221         {222             // No preparation needs to be done.223         }224 225         // Implements the IDataGridViewEditingControl226         // .RepositionEditingControlOnValueChange property.227         public bool RepositionEditingControlOnValueChange228         {229             get230             {231                 return false;232             }233         }234 235         // Implements the IDataGridViewEditingControl236         // .EditingControlDataGridView property.237         public DataGridView EditingControlDataGridView238         {239             get240             {241                 return dataGridView;242             }243             set244             {245                 dataGridView = value;246             }247         }248 249         // Implements the IDataGridViewEditingControl250         // .EditingControlValueChanged property.251         public bool EditingControlValueChanged252         {253             get254             {255                 return valueChanged;256             }257             set258             {259                 valueChanged = value;260             }261         }262 263         // Implements the IDataGridViewEditingControl264         // .EditingPanelCursor property.265         public Cursor EditingPanelCursor266         {267             get268             {269                 return base.Cursor;270             }271         }272 273         protected override void OnAfterExpand(TreeViewEventArgs e)274         {275             base.OnAfterExpand(e);276             this.dataGridView.Columns[this.dataGridView.CurrentCell.ColumnIndex].Width = this.Width+10;277             this.dataGridView.Rows[this.dataGridView.CurrentCell.RowIndex].Height = this.Height+20;278            279         }280         protected override void OnAfterSelect(TreeViewEventArgs e)281         {282             // Notify the DataGridView that the contents of the cell283             // have changed.284             valueChanged = true;285             this.EditingControlDataGridView.NotifyCurrentCellDirty(true);286             base.OnAfterSelect(e);287             288         }289        290     }291 292 293 294 }