[DevExpress] disable TreeListNode CheckBox and treelistnode

[DevExpress] disable TreeListNode CheckBox and treelistnode

In actual development, you need to set the node uncheckable according to the conditions. You can view the DevExpress document and find that the combined use of the CustomDrawNodeCheckBox and BeforeCheckNode events can be achieved, generally, the rules that cannot be checked when setting nodes are the same, so code is slightly encapsulated.

Key code:

/// <Summary> /// disable CheckBox /// description /// use it in the CustomDrawNodeCheckBox event /// </summary> /// <param name = "tree"> TreeList </param> /// <param name = "conditionHanlder"> DeleGate </param> /// <param name = "e"> CustomDrawNodeCheckBoxEventArgs </param> public static void DisabledCheckBox (this TreeListNode tree, predicate <TreeListNode> conditionHanlder, CustomDrawNodeCheckBoxEventArgs e) {if (conditionHanlder (e. node) {e. objectArgs. state = ObjectState. disabled ;}} /// <summary> /// the CheckBox of the forbidden node // description /// use this method in the BeforeCheckNode event /// </summary> /// <param name =" tree "> TreeListNode </param> // <param name =" conditionHanlder "> DeleGate </param> // <param name =" e "> CheckNodeEventArgs </param> public static void DisabledSetCheckBox (this TreeListNode tree, predicate <TreeListNode> conditionHanlder, CheckNodeEventArgs e) {if (conditionHanlder (e. node) {e. canCheck = false ;}}

Example:

/// <Summary> // CustomDrawNodeCheckBox event // </summary> void LHTree_CustomDrawNodeCheckBox (object sender, CustomDrawNodeCheckBoxEventArgs e) {e. node. disabledCheckBox (DisableNodeCheckBoxRule, e);} // <summary> // BeforeCheckNode event // </summary> void dispatch (object sender, CheckNodeEventArgs e) {e. node. disabledSetCheckBox (DisableNodeCheckBoxRule, e );} /// <summary> /// Disable TreeListNode rule // </summary> /// <param name = "node"> </param> /// <returns> </returns> private bool DisableNodeCheckBoxRule (TreeListNode node) {bool _ disable = false; if (OpLampCfgList. count> 0) {string _ cabId = OpLampCfgList [0]. cabID; NodeType _ curType = node. getNodeType (); if (_ curType = NodeType. lamp) // when the node is of the Lamp type and the parent node KEYID is equal to _ cabId, block Checkbox {_ disable = node. parentNode. parentNode. getKeyID (). equals (_ cabId);} if (_ curType = NodeType. pole) // when the node is of the Pole type and the parent node KEYID is equal to _ cabId, the Checkbox {_ disable = node is blocked. parentNode. getKeyID (). equals (_ cabId);} if (_ curType = NodeType. cab & node. getKeyID (). equals (_ cabId) // when the node is of the Box Type KEYID equal to _ cabId, block Checkbox {_ disable = true;} if (_ curType = NodeType. area | _ curType = NodeType. cabsGroupRoot) // when the node type is equal to the region or root node, block Checkbox {_ disable = true ;}} return _ disable ;}

Code effect:

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Hope this is helpful!

Q: How does the DEVExpress TreeList control bind data? Which event triggers binding? Now

Bind
Private void initTree ()
{

String sqltree = "select fitemid id, fnumber code, fname name, fparentid parentid from T_ITEM where fitemclassid = 4 and fdeleted = 0 and substring (fnumber, 1, 1) = '8' and fdetail = 0 ";
DataTable dtTree = SqlFunc. ExecSQL (sqltree );
TreeList1.DataSource = dtTree;
TreeList1.Columns ["id"]. Visible = false;
TreeList1.Columns ["parentid"]. Visible = false;
TreeList1.ExpandAll ();
GridView1.OptionsView. AllowCellMerge = true;
}
Click Event
Private void treelistpolicfocusednodechanged (object sender, DevExpress. XtraTreeList. FocusedNodeChangedEventArgs e)
{
DataRowView drv = (DataRowView) treeList1.GetDataRecordByNode (treeList1.FocusedNode );
DataRow dr = drv. Row;
Int p = Convert. ToInt32 (dr [0]);
..................
}
 
How to bind DevExpress in C # To XtraTreeList Parent and Child Nodes

This. treeList. DataSource = dt;

This. treeList. ParentFieldName = "Father_City_Id ";

This. treeList. KeyFieldName = "CityId ";

This is almost the case.