接着上文这里我们来说说状态数据时如何加载的。
虽然在Control中有调用状态转存的方法，但是这里有一个判断条件 if (_controlState >= ControlState.ViewStateLoaded) 一般的get请求这里的条件是不满足的。internal enum ControlState
{ Constructed, FrameworkInitialized, ChildrenInitialized, Initialized, ViewStateLoaded, Loaded, PreRendered }我们知道在page的ProcessRequest中this.ControlState = ControlState.FrameworkInitialized; ProcessRequestMain方法中在Init后有调用this.InitRecursive(null);在这个方法里面有这么一句_controlState = ControlState.Initialized;，在LoadAllState()方法中有这么一句 base.LoadViewStateRecursive(second.Second);，而LoadViewStateRecursive中又有_controlState = ControlState.ViewStateLoaded这句带代码，所以我们在Page_load中动态条件控件时， if (_controlState >= ControlState.ViewStateLoaded)条件成立，如图：
所以在运行this.form1.Controls.Add(txt);这句以前，txt的值为demo1，
如图
但是运行以后之就发生变化了：
当然这里的txt.Text值也是我上次post过来的旧值，新值是在控件的LoadPostData方法中重新绑定。在默认的LoadViewStateRecursive方法中有一个很重要的判断
internal void LoadViewStateRecursive(object savedState) {
// nothing to do if we have no state if (savedState == null || flags[disableViewState]) return;。。。。。。。
_controlState = ControlState.ViewStateLoaded
}大家看到我上面是一个CustTextBoxt : TextBox控件，如果我们直接添加TextBox控件的话，那么着这里的txt.Text一直都是demo1，可见控件动态添加的时候是否加载状态数 据与状态数据的保存有关。而状态数据的保存主要就是SaveViewState完成的，这里我第一次post的时候SaveViewState返回数据：
所以第二次能取到上次post过来的数据。
其中与SaveViewState有关的方法主要有：
public class TextBox : WebControl, IPostBackDataHandler, IEditableTextControl { protected override object SaveViewState() { if (SaveTextViewState == false) { ViewState.SetItemDirty("Text", false); } return base.SaveViewState(); } private bool SaveTextViewState { get { // // Must be saved when // 1. There is a registered event handler for SelectedIndexChanged // 2. Control is not enabled or visible, because the browser's post data will not include this control // 3. The instance is a derived instance, which might be overriding the OnTextChanged method if (TextMode == TextBoxMode.Password) { return false; } if ((Events[EventTextChanged] != null) || (IsEnabled == false) || (Visible == false) || (ReadOnly) || (this.GetType() != typeof(TextBox))) { return true; } return false; } } } public class WebControl : Control, IAttributeAccessor { protected override object SaveViewState() { Pair myState = null; // Save values cached out of view state if (_webControlFlags[disabledDirty]) { ViewState["Enabled"] = !flags[isWebControlDisabled]; } if (ControlStyleCreated) { // the style shares the StateBag of its owner WebControl // call SaveViewState to let style participate in state management ControlStyle.SaveViewState(); } object baseState = base.SaveViewState(); object aState = null; if (attrState != null) { aState = attrState.SaveViewState(); } if (baseState != null || aState != null) { myState = new Pair(baseState, aState); } return myState; }}public class Control : IComponent, IParserAccessor, IUrlResolutionService, IDataBindingsAccessor, IControlBuilderAccessor, IControlDesignerAccessor, IExpressionsAccessor { protected virtual object SaveViewState() { // Save values cached out of view state if (flags[visibleDirty]) { ViewState["Visible"] = !flags[invisible]; } if (flags[validateRequestModeDirty]) { ViewState["ValidateRequestMode"] = (int)ValidateRequestMode; } if (_viewState != null) return _viewState.SaveViewState(); return null; }}public sealed class StateBag : IStateManager, IDictionary { internal object SaveViewState() { ArrayList data = null; if (bag.Count != 0) { IDictionaryEnumerator e = bag.GetEnumerator(); while (e.MoveNext()) { StateItem item = (StateItem)(e.Value); if (item.IsDirty) { if (data == null) { data = new ArrayList(); }#if OBJECTSTATEFORMATTER data.Add(new IndexedString((string)e.Key));#else data.Add(e.Key);#endif data.Add(item.Value); } } } return data; } } 到这里我们知道保存状态信息主要是在StateBag 的SaveViewState方法中，这里有一个检查 if (item.IsDirty) ，在TextBox的SaveViewState方法中有一个判断
if (SaveTextViewState == false) { ViewState.SetItemDirty("Text", false); }
与它的SaveTextViewState 属性有关。
那么我们可以总结一下：动态创建的控件默认是在被添加的时候加载器状态数据，如果是静态添加的数据那就是LoadAllState来处理状态数据的加载。状态数据的加载与控件的SaveViewState密切相关，如果该方法的返回值为null既没有状态信息，那也不需要加载什么状态信息了。