我们可以自定义datagridview的datagridviewcolumn来实现自定义的列，下面介绍一下如何通过扩展datagridviewcolumn来实现一个treeviewcolumn
1.treeviewcolumn类
treeviewcolumn继承自datagridviewcolumn，为了动态给treeviewcolumn传入一个treeview，这里暴露出一个公共属性_root，可以绑定一个初始化的treeview. 另外需要重写datagridcell类型的celltemplate，这里返还一个treeviewcell（需要自定义）
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/// <summary> /// host treeview in datagridview cell /// </summary> public class treeviewcolumn : datagridviewcolumn { public treeviewcolumn() : base(new treeviewcell()) { } [description("set treeview root in datagridview cell"), category("treeview")] public treeview _root { get{return roots.tree;} set{roots.tree=value;} } public override datagridviewcell celltemplate { get { return base.celltemplate; } set { // ensure that the cell used for the template is a treeviewcell. if (value != null && !value.gettype().isassignablefrom(typeof(treeviewcell))) { throw new invalidcastexception("must be a treeviewcell"); } base.celltemplate = value; } } } |
2.treeviewcell类
上面treeviewcolumn重写了celltemplate，返回的就是自定义的treeviewcell，这里就是具体实现其逻辑。一般来说选择树控件的节点后，返回的是一个文本信息，是文本类型，可以继承datagridviewtextboxcell,并重写initializeeditingcontrol来进行自定义的datagridview.editingcontrol （编辑控件）。
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public class treeviewcell : datagridviewtextboxcell { public treeviewcell() : base() { //初始设置 } public override void initializeeditingcontrol(int rowindex, object initialformattedvalue, datagridviewcellstyle datagridviewcellstyle) { // set the value of the editing control to the current cell value. base.initializeeditingcontrol(rowindex, initialformattedvalue, datagridviewcellstyle); treevieweditingcontrol ctl = datagridview.editingcontrol as treevieweditingcontrol; // use the default row value when value property is null. if (this.value == null) { ctl.selectednode =new treenode( this.defaultnewrowvalue.tostring()); } else { ctl.selectednode = new treenode(this.value.tostring()); } } public override type edittype { get { // return the type of the editing control that calendarcell uses. return typeof(treevieweditingcontrol); } } public override type valuetype { get { // return the type of the value that calendarcell contains. return typeof(string); } } public override object defaultnewrowvalue { get { // use the current date and time as the default value. return ""; } } } |
3.treevieweditingcontrol类
treevieweditingcontrol为编辑控件，当用户编辑treeviewcell时，显示的为树编辑控件，需要继承treeview，同时实现idatagridvieweditingcontrol接口，实现以下方法：
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public class treevieweditingcontrol : treeview, idatagridvieweditingcontrol { datagridview datagridview; private bool valuechanged = false; int rowindex; public treevieweditingcontrol() { try { //必须加roots.tree.nodes[].clone() 否则报错 不能在多处增添或插入项，必须首先将其从当前位置移除或将其克隆 this.nodes.add(roots.tree.nodes[].clone() as treenode); this.selectednode = this.nodes[]; } catch (exception ex) { messagebox.show(ex.message); } } // implements the idatagridvieweditingcontrol.editingcontrolformattedvalue // property. public object editingcontrolformattedvalue { get { return this.selectednode.text; } set { if (value is string) { try { // this will throw an exception of the string is // null, empty, or not in the format of a date. this.selectednode = new treenode((string)value); } catch { // in the case of an exception, just use the // default value so we're not left with a null // value. this.selectednode = new treenode(""); } } } } // implements the // idatagridvieweditingcontrol.geteditingcontrolformattedvalue method. public object geteditingcontrolformattedvalue( datagridviewdataerrorcontexts context) { return editingcontrolformattedvalue; } // implements the // idatagridvieweditingcontrol.applycellstyletoeditingcontrol method. public void applycellstyletoeditingcontrol( datagridviewcellstyle datagridviewcellstyle) { this.font = datagridviewcellstyle.font; this.forecolor = datagridviewcellstyle.forecolor; this.backcolor = datagridviewcellstyle.backcolor; } // implements the idatagridvieweditingcontrol.editingcontrolrowindex // property. public int editingcontrolrowindex { get { return rowindex; } set { rowindex = value; } } // implements the idatagridvieweditingcontrol.editingcontrolwantsinputkey // method. public bool editingcontrolwantsinputkey( keys key, bool datagridviewwantsinputkey) { // let the treeviewpicker handle the keys listed. switch (key & keys.keycode) { case keys.left: case keys.up: case keys.down: case keys.right: case keys.home: case keys.end: case keys.pagedown: case keys.pageup: return true; default: return !datagridviewwantsinputkey; } } // implements the idatagridvieweditingcontrol.prepareeditingcontrolforedit // method. public void prepareeditingcontrolforedit(bool selectall) { // no preparation needs to be done. } // implements the idatagridvieweditingcontrol // .repositioneditingcontrolonvaluechange property. public bool repositioneditingcontrolonvaluechange { get { return false; } } // implements the idatagridvieweditingcontrol // .editingcontroldatagridview property. public datagridview editingcontroldatagridview { get { return datagridview; } set { datagridview = value; } } // implements the idatagridvieweditingcontrol // .editingcontrolvaluechanged property. public bool editingcontrolvaluechanged { get { return valuechanged; } set { valuechanged = value; } } // implements the idatagridvieweditingcontrol // .editingpanelcursor property. public cursor editingpanelcursor { get { return base.cursor; } } protected override void onafterexpand(treevieweventargs e) { base.onafterexpand(e); this.datagridview.columns[this.datagridview.currentcell.columnindex].width = this.width+; this.datagridview.rows[this.datagridview.currentcell.rowindex].height = this.height+; } protected override void onafterselect(treevieweventargs e) { // notify the datagridview that the contents of the cell // have changed. valuechanged = true; this.editingcontroldatagridview.notifycurrentcelldirty(true); base.onafterselect(e); } } |
为了在不同类之间传递参数，定义一个全局静态类：
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/// <summary> /// 静态类的静态属性，用于在不同class间传递参数 /// </summary> public static class roots { //从前台绑定树 public static treeview tree = null; } |
完整代码为：
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using system;using system.collections.generic;using system.linq;using system.text;using system.windows.forms;using system.componentmodel;namespace host_controls_in_windows_forms_datagridview_cells{ /// <summary> /// 静态类的静态属性，用于在不同class间传递参数 /// </summary> public static class roots { //从前台绑定树 public static treeview tree = null; } /// <summary> /// host treeview in datagridview cell /// </summary> public class treeviewcolumn : datagridviewcolumn { public treeviewcolumn() : base(new treeviewcell()) { } [description("set treeview root in datagridview cell"), category("treeview")] public treeview _root { get{return roots.tree;} set{roots.tree=value;} } public override datagridviewcell celltemplate { get { return base.celltemplate; } set { // ensure that the cell used for the template is a treeviewcell. if (value != null && !value.gettype().isassignablefrom(typeof(treeviewcell))) { throw new invalidcastexception("must be a treeviewcell"); } base.celltemplate = value; } } } //---------------------------------------------------------------------- public class treeviewcell : datagridviewtextboxcell { public treeviewcell() : base() { //初始设置 } public override void initializeeditingcontrol(int rowindex, object initialformattedvalue, datagridviewcellstyle datagridviewcellstyle) { // set the value of the editing control to the current cell value. base.initializeeditingcontrol(rowindex, initialformattedvalue, datagridviewcellstyle); treevieweditingcontrol ctl = datagridview.editingcontrol as treevieweditingcontrol; // use the default row value when value property is null. if (this.value == null) { ctl.selectednode =new treenode( this.defaultnewrowvalue.tostring()); } else { ctl.selectednode = new treenode(this.value.tostring()); } } public override type edittype { get { // return the type of the editing control that calendarcell uses. return typeof(treevieweditingcontrol); } } public override type valuetype { get { // return the type of the value that calendarcell contains. return typeof(string); } } public override object defaultnewrowvalue { get { // use the current date and time as the default value. return ""; } } } //-----------------------------------------------------------------public class treevieweditingcontrol : treeview, idatagridvieweditingcontrol { datagridview datagridview; private bool valuechanged = false; int rowindex; public treevieweditingcontrol() { try { //必须加roots.tree.nodes[].clone() 否则报错 不能在多处增添或插入项，必须首先将其从当前位置移除或将其克隆 this.nodes.add(roots.tree.nodes[].clone() as treenode); this.selectednode = this.nodes[]; } catch (exception ex) { messagebox.show(ex.message); } } // implements the idatagridvieweditingcontrol.editingcontrolformattedvalue // property. public object editingcontrolformattedvalue { get { return this.selectednode.text; } set { if (value is string) { try { // this will throw an exception of the string is // null, empty, or not in the format of a date. this.selectednode = new treenode((string)value); } catch { // in the case of an exception, just use the // default value so we're not left with a null // value. this.selectednode = new treenode(""); } } } } // implements the // idatagridvieweditingcontrol.geteditingcontrolformattedvalue method. public object geteditingcontrolformattedvalue( datagridviewdataerrorcontexts context) { return editingcontrolformattedvalue; } // implements the // idatagridvieweditingcontrol.applycellstyletoeditingcontrol method. public void applycellstyletoeditingcontrol( datagridviewcellstyle datagridviewcellstyle) { this.font = datagridviewcellstyle.font; this.forecolor = datagridviewcellstyle.forecolor; this.backcolor = datagridviewcellstyle.backcolor; } // implements the idatagridvieweditingcontrol.editingcontrolrowindex // property. public int editingcontrolrowindex { get { return rowindex; } set { rowindex = value; } } // implements the idatagridvieweditingcontrol.editingcontrolwantsinputkey // method. public bool editingcontrolwantsinputkey( keys key, bool datagridviewwantsinputkey) { // let the treeviewpicker handle the keys listed. switch (key & keys.keycode) { case keys.left: case keys.up: case keys.down: case keys.right: case keys.home: case keys.end: case keys.pagedown: case keys.pageup: return true; default: return !datagridviewwantsinputkey; } } // implements the idatagridvieweditingcontrol.prepareeditingcontrolforedit // method. public void prepareeditingcontrolforedit(bool selectall) { // no preparation needs to be done. } // implements the idatagridvieweditingcontrol // .repositioneditingcontrolonvaluechange property. public bool repositioneditingcontrolonvaluechange { get { return false; } } // implements the idatagridvieweditingcontrol // .editingcontroldatagridview property. public datagridview editingcontroldatagridview { get { return datagridview; } set { datagridview = value; } } // implements the idatagridvieweditingcontrol // .editingcontrolvaluechanged property. public bool editingcontrolvaluechanged { get { return valuechanged; } set { valuechanged = value; } } // implements the idatagridvieweditingcontrol // .editingpanelcursor property. public cursor editingpanelcursor { get { return base.cursor; } } protected override void onafterexpand(treevieweventargs e) { base.onafterexpand(e); this.datagridview.columns[this.datagridview.currentcell.columnindex].width = this.width+; this.datagridview.rows[this.datagridview.currentcell.rowindex].height = this.height+; } protected override void onafterselect(treevieweventargs e) { // notify the datagridview that the contents of the cell // have changed. valuechanged = true; this.editingcontroldatagridview.notifycurrentcelldirty(true); base.onafterselect(e); } }} |
当编辑无误后，可以在添加列的时候看到treeviewcolumn类型。此类型暴露出一个_root属性，可以绑定外部的一个带数据的treeview。
运行代码，单击单元格，进入编辑状态，可以看到如下界面：
以上内容是小编给大家介绍的c#自定义datagridviewcolumn显示treeview 的全部叙述，希望大家喜欢。
