//------------------------------------------------------------------------------

// <copyright file="ControlUtil.cs" company="Microsoft">

// Copyright (c) Microsoft Corporation. All rights reserved.

// </copyright>

//------------------------------------------------------------------------------

using System;

using System.Collections.Generic;

using System.Text;

using System.Web.Resources;

using System.Web.UI;

namespace System.Web.UI {

internal class ControlUtil {

internal static Control FindTargetControl(string controlID, Control control, bool searchNamingContainers) {

Control foundControl;

if (searchNamingContainers) {

Control currentContainer;

foundControl = null;

// DevDiv 73305: Do not assume starting control is not a naming container.

if (control is INamingContainer) {

currentContainer = control;

}

else {

currentContainer = control.NamingContainer;

}

do {

foundControl = currentContainer.FindControl(controlID);

currentContainer = currentContainer.NamingContainer;

}

while (foundControl == null && currentContainer != null);

}

else {

foundControl = control.FindControl(controlID);

}

return foundControl;

}

internal static bool IsBuiltInHiddenField(string hiddenFieldName) {

// Returns true is the field name represents a hidden field generated

// by ASP.NET's core runtime. This includes fields such as ViewState and

// EventValidation, but not ones generated by specific controls such as

// TreeView and WebParts.

// If the field is less than two chars long it's not built-in. (Perf)

if (hiddenFieldName.Length <= 2) {

return false;

}

// If it doesn't start with two underscores, it's not built-in. (Perf)

if (hiddenFieldName[0] != '_' ||

hiddenFieldName[1] != '_') {

return false;

}

// Examine list of built-in ASP.NET fields. The list was created by examining

// the ASP.NET source code for hidden field registration and rendering.

// We exclude __VIEWSTATEENCRYPTED and __VIEWSTATEFIELDCOUNT from the list

// since they're covered by the general __VIEWSTATE part.

return

hiddenFieldName.StartsWith("__VIEWSTATE", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__EVENTVALIDATION", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__LASTFOCUS", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__SCROLLPOSITIONX", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__SCROLLPOSITIONY", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__EVENTTARGET", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__EVENTARGUMENT", StringComparison.Ordinal) ||

String.Equals(hiddenFieldName, "__PREVIOUSPAGE", StringComparison.Ordinal);

}

}

}