C# FindNodeBiFieldValue返回null
逻辑:C# FindNodeBiFieldValue返回null,c#,winforms,devexpress,C#,Winforms,Devexpress,逻辑: -根据条件“expand=true”从数据表行中选择 -搜索行 -根据字符串字段的值,我们可以在“托盘列表”中找到节点 在方法ExpandCurentNode()的行中 TreeListNode node = treeList1.FindNodeByFieldValue("NodeName", name); 我们得到空值 问题 为什么FindNodeByFieldValue返回null 说明 树列表填充方法DataBinding() 属性PopulateServiceColumns=
-根据条件“expand=true”从数据表行中选择
-搜索行
-根据字符串字段的值,我们可以在“托盘列表”中找到节点 在方法
ExpandCurentNode()
的行中
TreeListNode node = treeList1.FindNodeByFieldValue("NodeName", name);
我们得到空值
问题为什么FindNodeByFieldValue返回null 说明
树列表填充方法
DataBinding()
属性
PopulateServiceColumns=true
连接代码
public void connect()
{
string catBD = @"с:\db\db.01.accdb";
string conBD = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0}", catBD);
OleDbConnection connection = new OleDbConnection(conBD);
connection.Open();
string query1 = "SELECT * FROM TableTreeViewNoAi_12";
OleDbCommand cmd1 = new OleDbCommand(query1, connection);
dt = new DataTable();
dt.Columns.Add("ID", typeof(int));
dt.Columns["ID"].AutoIncrement = true;
dt.Columns["ID"].AutoIncrementSeed = 44;
dt.Columns["ID"].AutoIncrementStep = 1;
dt.Columns.Add("PrID", typeof(int));
dt.Columns.Add("sorting", typeof(int));
dt.Columns.Add("NodeName", typeof(string));
dt.Columns.Add("Description", typeof(string));
dt.Columns.Add("Comment", typeof(string));
dt.Columns.Add("dateN", typeof(string));
dt.Columns.Add("Cost", typeof(int));
dt.Columns.Add("typeRecord", typeof(string));
dt.Columns.Add("stImageInd", typeof(int));
dt.Columns.Add("expand", typeof(bool));
dt.Columns.Add("focus", typeof(bool));
try
{
adapter = new OleDbDataAdapter(cmd1);
cmdBuilder = new OleDbCommandBuilder(adapter);
adapter.UpdateCommand = cmdBuilder.GetUpdateCommand();
adapter.InsertCommand = cmdBuilder.GetInsertCommand();
}
catch (Exception ex)
{
string s = ex.Message;
throw;
}
adapter.Fill(dt);
dt.RowChanged += new DataRowChangeEventHandler(Row_Changed);
}
public void DataBinding()
{
// Чтобы отобразить поля "KeyFieldName" и "ParentFieldName"
// Свойство - PopulateServiceColumns = true
// Привязка к ключевым полям
treeList1This.KeyFieldName = "ID";
treeList1This.ParentFieldName = "PrID";
treeList1This.DataSource = dt;
// dataGridView1.DataSource = dt;
}
表格代码
private void Frm29UC_Load(object sender, EventArgs e)
{
treeList1.BestFitColumns(); // расширить поля
ExpandCurentNode(); // восстановление дерева после открытия
}
public void ExpandCurentNode() // Восстановление состояния после открытия дерева
{
var selectedDt = conectDB.dt.Select("expand = true"); // DataTable.Select
int i = selectedDt.Length;
foreach (var b in selectedDt)
{
string name = b["NodeName"].ToString();
TreeListNode node = treeList1.FindNodeByFieldValue("NodeName", name); // +- string s = node.GetValue("NodeName").ToString();
node.Expand();
ExpandParentNode(node);
}
}
调用ExpandCurentNode方法时,确保树列表已完全初始化。为此,请在方法之前调用该方法