本文整理汇总了C#中System.Web.UI.WebControls.HierarchicalDataBoundControl类的典型用法代码示例。如果您正苦于以下问题：C# HierarchicalDataBoundControl类的具体用法？C# HierarchicalDataBoundControl怎么用？C# HierarchicalDataBoundControl使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
HierarchicalDataBoundControl类属于System.Web.UI.WebControls命名空间，在下文中一共展示了HierarchicalDataBoundControl类的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: PerformDataBinding
//引入命名空间
using System;
using System.Collections;
using System.ComponentModel;
using System.Security.Permissions;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Samples.AspNet.CS.Controls {
[AspNetHostingPermission(SecurityAction.Demand,
Level=AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermission(SecurityAction.InheritanceDemand,
Level=AspNetHostingPermissionLevel.Minimal)]
public class GeneologyTree : HierarchicalDataBoundControl {
private TreeNode rootNode;
public TreeNode RootNode {
get {
rootNode ??= new TreeNode(String.Empty);
return rootNode;
}
}
private ArrayList nodes;
public ArrayList Nodes {
get {
if (null == nodes) {
nodes = new ArrayList();
}
return nodes;
}
}
public string DataTextField {
get {
object o = ViewState["DataTextField"];
return((o == null) ? string.Empty : (string)o);
}
set {
ViewState["DataTextField"] = value;
if (Initialized) {
OnDataPropertyChanged();
}
}
}
private int _maxDepth = 0;
protected override void PerformDataBinding() {
base.PerformDataBinding();
// Do not attempt to bind data if there is no
// data source set.
if (!IsBoundUsingDataSourceID && (DataSource == null)) {
return;
}
HierarchicalDataSourceView view = GetData(RootNode.DataPath);
if (view == null) {
throw new InvalidOperationException
("No view returned by data source control.");
}
IHierarchicalEnumerable enumerable = view.Select();
if (enumerable != null) {
Nodes.Clear();
try {
RecurseDataBindInternal(RootNode, enumerable, 1);
}
finally {
}
}
}
private void RecurseDataBindInternal(TreeNode node,
IHierarchicalEnumerable enumerable, int depth) {
foreach(object item in enumerable) {
IHierarchyData data = enumerable.GetHierarchyData(item);
if (null != data) {
// Create an object that represents the bound data
// to the control.
TreeNode newNode = new TreeNode();
RootViewNode rvnode = new RootViewNode();
rvnode.Node = newNode;
rvnode.Depth = depth;
// The dataItem is not just a string, but potentially
// an XML node or some other container.
// If DataTextField is set, use it to determine which
// field to render. Otherwise, use the first field.
if (DataTextField.Length > 0) {
newNode.Text = DataBinder.GetPropertyValue
(data, DataTextField, null);
}
else {
PropertyDescriptorCollection props =
TypeDescriptor.GetProperties(data);
// Set the "default" value of the node.
newNode.Text = String.Empty;
// Set the true data-bound value of the TextBox,
// if possible.
if (props.Count >= 1) {
if (null != props[0].GetValue(data)) {
newNode.Text =
props[0].GetValue(data).ToString();
}
}
}
Nodes.Add(rvnode);
if (data.HasChildren) {
IHierarchicalEnumerable newEnumerable =
data.GetChildren();
if (newEnumerable != null) {
RecurseDataBindInternal(newNode,
newEnumerable, depth+1 );
}
}
if ( _maxDepth < depth) _maxDepth = depth;
}
}
}
protected override void Render(HtmlTextWriter writer) {
writer.WriteLine("<PRE>");
int currentDepth = 1;
int currentTextLen = 0;
foreach (RootViewNode rvnode in Nodes) {
if (rvnode.Depth == currentDepth) {
string output = " " + rvnode.Node.Text + " ";
writer.Write(output);
currentTextLen = currentTextLen + output.Length;
}
else {
writer.WriteLine("");
// Some very basic white-space formatting
int halfLine = currentTextLen / 2;
for (int i=0;i<halfLine;i++) {
writer.Write(' ');
}
writer.Write('|');
writer.WriteLine("");
++currentDepth;
currentTextLen = 0;
for (int j=0;j<halfLine;j++) {
writer.Write(' ');
}
string output = " " + rvnode.Node.Text + " ";
writer.Write(output);
currentTextLen = currentTextLen + output.Length;
}
}
writer.WriteLine("</PRE>");
}
private class RootViewNode {
public TreeNode Node;
public int Depth;
}
}
}