控件生命周期

第一次加载主要事件如下：
1:TrackViewState
2:OnPreRender
3:SaveViewState()
4:Render

回传时页面加载主要事件如下：

page.isPostBack
1:TrackViewState
2:LoadViewState
3:LoadPostData
4:RaisePostDataChangedEvent
5RaisePostBackEvent
6:OnPreRender
7:SaveViewState
8:Render
如果要回传。在Render的PostBackOptions的AutoPostBack = true;
如果要加载数据。在OnPreRender加this.Page.RegisterRequiresPostBack(this);

事例：

  1 using  System;
  2 using  System.Collections.Specialized;
  3 using  System.ComponentModel;
  4 using  System.Globalization;
  5 using  System.Security.Permissions;
  6 using  System.Web;
  7 using  System.Web.UI;
  8 using  System.Web.UI.WebControls;
  9
 10 [assembly: TagPrefix( " Invent.Controls " ,  " Invent " )]
 11 namespace  InventControls
 12 {
 13   // [SupportsEventValidation, ControlValueProperty("Checked"), DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"), DefaultEvent("CheckedChanged"), Designer("System.Web.UI.Design.WebControls.CheckBoxDesigner, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"), DefaultProperty("Text"), AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal), AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)]
 14    public class InventCheckBox : WebControl, IPostBackDataHandler, ICheckBoxControl
 15    {
 16        [Description("Control_OnServerCheckChanged"), Category("Action")]
 17        public event EventHandler CheckedChanged
 18        {
 19            add
 20            {
 21                base.Events.AddHandler(InventCheckBox.EventCheckedChanged, value);
 22            }
 23            remove
 24            {
 25                base.Events.RemoveHandler(InventCheckBox.EventCheckedChanged, value);
 26            }
 27        }
 28
 29        static InventCheckBox()
 30        {
 31            InventCheckBox.EventCheckedChanged = new object();
 32        }
 33
 34        public InventCheckBox() : base(HtmlTextWriterTag.Input)
 35        {
 36        }
 37
 38        protected override void AddAttributesToRender(HtmlTextWriter writer)
 39        {
 40            //base.AddDisplayInlineBlockIfNeeded(writer);
 41        }
 42
 43        protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection)
 44        {
 45            bool flag1 = false;
 46            string text1 = postCollection[postDataKey];
 47            bool flag2 = !string.IsNullOrEmpty(text1);
 48            if (flag2)
 49            {
 50                //base.ValidateEvent(postDataKey);
 51            }
 52            flag1 = flag2 != this.Checked;
 53            this.Checked = flag2;
 54            return flag1;
 55        }
 56
 57        protected override void LoadViewState(object savedState)
 58        {
 59            if (savedState != null)
 60            {
 61                Triplet triplet1 = (Triplet) savedState;
 62                base.LoadViewState(triplet1.First);
 63                if (triplet1.Second != null)
 64                {
 65                    if (this._inputAttributesState == null)
 66                    {
 67                        this._inputAttributesState = new StateBag();
 68                        ((IStateManager)this._inputAttributesState).TrackViewState();
 69                    }
 70                    ((IStateManager)this._inputAttributesState).LoadViewState(triplet1.Second);
 71                }
 72                if (triplet1.Third != null)
 73                {
 74                    if (this._labelAttributesState == null)
 75                    {
 76                        this._labelAttributesState = new StateBag();
 77                        ((IStateManager)this._labelAttributesState).TrackViewState();
 78                    }
 79                    ((IStateManager)this._labelAttributesState).LoadViewState(triplet1.Second);
 80                }
 81            }
 82        }
 83
 84        protected virtual void OnCheckedChanged(EventArgs e)
 85        {
 86            EventHandler handler1 = (EventHandler) base.Events[InventCheckBox.EventCheckedChanged];
 87            if (handler1 != null)
 88            {
 89                handler1(this, e);
 90            }
 91        }
 92
 93        protected override void OnPreRender(EventArgs e)
 94        {
 95            base.OnPreRender(e);
 96            bool flag1 = this.AutoPostBack;
 97            if ((this.Page != null) && base.IsEnabled)
 98            {
 99                this.Page.RegisterRequiresPostBack(this);
100                //if (flag1)
101                //{
102                //    this.Page.RegisterPostBackScript();
103                //    this.Page.RegisterFocusScript();
104                //    if (this.CausesValidation && (this.Page.GetValidators(this.ValidationGroup).Count > 0))
105                //    {
106                //        this.Page.RegisterWebFormsScript();
107                //    }
108                //}
109            }
110            if (!this.SaveCheckedViewState(flag1))
111            {
112                this.ViewState.SetItemDirty("Checked", false);
113                //if ((this.Page != null) && base.IsEnabled)
114                //{
115                //    this.Page.RegisterEnabledControl(this);
116                //}
117            }
118        }
119
120        protected virtual void RaisePostDataChangedEvent()
121        {
122            if (this.AutoPostBack)
123            {
124                //this.Page.AutoPostBackControl = this;
125                if (this.CausesValidation)
126                {
127                    this.Page.Validate(this.ValidationGroup);
128                }
129            }
130            this.OnCheckedChanged(EventArgs.Empty);
131        }
132
133        protected override void Render(HtmlTextWriter writer)
134        {
135            this.AddAttributesToRender(writer);
136            if (this.Page != null)
137            {
138                this.Page.VerifyRenderingInServerForm(this);
139            }
140            bool flag1 = false;
141            if (base.ControlStyleCreated)
142            {
143                Style style1 = base.ControlStyle;
144                if (!style1.IsEmpty)
145                {
146                    style1.AddAttributesToRender(writer, this);
147                    flag1 = true;
148                }
149            }
150            if (!base.IsEnabled)
151            {
152                writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
153                flag1 = true;
154            }
155            string text1 = this.ToolTip;
156            if (text1.Length > 0)
157            {
158                writer.AddAttribute(HtmlTextWriterAttribute.Title, text1);
159                flag1 = true;
160            }
161            string text2 = null;
162            if (base.HasAttributes)
163            {
164                System.Web.UI.AttributeCollection collection1 = base.Attributes;
165                string text3 = collection1["value"];
166                if (text3 != null)
167                {
168                    collection1.Remove("value");
169                }
170                text2 = collection1["onclick"];
171                if (text2 != null)
172                {
173                    text2 = Util.EnsureEndWithSemiColon(text2);
174                    collection1.Remove("onclick");
175                }
176                if (collection1.Count != 0)
177                {
178                    collection1.AddAttributes(writer);
179                    flag1 = true;
180                }
181                if (text3 != null)
182                {
183                    collection1["value"] = text3;
184                }
185            }
186            if (flag1)
187            {
188                writer.RenderBeginTag(HtmlTextWriterTag.Span);
189            }
190            string text4 = this.Text;
191            string text5 = this.ClientID;
192            if (text4.Length != 0)
193            {
194                if (this.TextAlign == System.Web.UI.WebControls.TextAlign.Left)
195                {
196                    this.RenderLabel(writer, text4, text5);
197                    this.RenderInputTag(writer, text5, text2);
198                }
199                else
200                {
201                    this.RenderInputTag(writer, text5, text2);
202                    this.RenderLabel(writer, text4, text5);
203                }
204            }
205            else
206            {
207                this.RenderInputTag(writer, text5, text2);
208            }
209            if (flag1)
210            {
211                writer.RenderEndTag();
212            }
213        }
214
215        internal virtual void RenderInputTag(HtmlTextWriter writer, string clientID, string onClick)
216        {
217            if (clientID != null)
218            {
219                writer.AddAttribute(HtmlTextWriterAttribute.Id, clientID);
220            }
221            writer.AddAttribute(HtmlTextWriterAttribute.Type, "checkbox");
222            if (this.UniqueID != null)
223            {
224                writer.AddAttribute(HtmlTextWriterAttribute.Name, this.UniqueID);
225            }
226            if (this._valueAttribute != null)
227            {
228                writer.AddAttribute(HtmlTextWriterAttribute.Value, this._valueAttribute);
229            }
230            if (this.Checked)
231            {
232                writer.AddAttribute(HtmlTextWriterAttribute.Checked, "checked");
233            }
234            if (!base.IsEnabled)
235            {
236                writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
237            }
238            if ((this.AutoPostBack && (this.Page != null)))
239            {
240                PostBackOptions options1 = new PostBackOptions(this, string.Empty);
241                if (this.CausesValidation && (this.Page.GetValidators(this.ValidationGroup).Count > 0))
242                {
243                    options1.PerformValidation = true;
244                    options1.ValidationGroup = this.ValidationGroup;
245                }
246                if (this.Page.Form != null)
247                {
248                    options1.AutoPostBack = true;
249                }
250                onClick = Util.MergeScript(onClick, this.Page.ClientScript.GetPostBackEventReference(options1, true));
251                writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
252               
253            }
254            else
255            {
256                if (this.Page != null)
257                {
258                    this.Page.ClientScript.RegisterForEventValidation(this.UniqueID);
259                }
260                if (onClick != null)
261                {
262                    writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
263                }
264            }
265            string text1 = this.AccessKey;
266            if (text1.Length > 0)
267            {
268                writer.AddAttribute(HtmlTextWriterAttribute.Accesskey, text1);
269            }
270            int num1 = this.TabIndex;
271            if (num1 != 0)
272            {
273                writer.AddAttribute(HtmlTextWriterAttribute.Tabindex, num1.ToString(NumberFormatInfo.InvariantInfo));
274            }
275            if ((this._inputAttributes != null) && (this._inputAttributes.Count != 0))
276            {
277                this._inputAttributes.AddAttributes(writer);
278            }
279            writer.RenderBeginTag(HtmlTextWriterTag.Input);
280            writer.RenderEndTag();
281        }
282
283        private void RenderLabel(HtmlTextWriter writer, string text, string clientID)
284        {
285            writer.AddAttribute(HtmlTextWriterAttribute.For, clientID);
286            if ((this._labelAttributes != null) && (this._labelAttributes.Count != 0))
287            {
288                this._labelAttributes.AddAttributes(writer);
289            }
290            writer.RenderBeginTag(HtmlTextWriterTag.Label);
291            writer.Write(text);
292            writer.RenderEndTag();
293        }
294
295        private bool SaveCheckedViewState(bool autoPostBack)
296        {
297            if ((((base.Events[InventCheckBox.EventCheckedChanged] != null) || !base.IsEnabled) || !this.Visible) || ((autoPostBack && (this.Page != null))))
298            {
299                return true;
300            }
301            Type type1 = base.GetType();
302            if ((type1 != typeof(InventCheckBox)) && (type1 != typeof(RadioButton)))
303            {
304                return true;
305            }
306            return false;
307        }
308
309        protected override object SaveViewState()
310        {
311            object obj1 = base.SaveViewState();
312            object obj2 = null;
313            object obj3 = null;
314            object obj4 = null;
315            if (this._inputAttributesState != null)
316            {
317                obj2 = ((IStateManager)this._inputAttributesState).SaveViewState();
318            }
319            if (this._labelAttributesState != null)
320            {
321                obj3 = ((IStateManager)this._labelAttributesState).SaveViewState();
322            }
323            if (((obj1 == null) && (obj2 == null)) && (obj3 == null))
324            {
325                return obj4;
326            }
327            return new Triplet(obj1, obj2, obj3);
328        }
329
330        bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection)
331        {
332            return this.LoadPostData(postDataKey, postCollection);
333        }
334
335        void IPostBackDataHandler.RaisePostDataChangedEvent()
336        {
337            this.RaisePostDataChangedEvent();
338        }
339
340        protected override void TrackViewState()
341        {
342            base.TrackViewState();
343            if (this._inputAttributesState != null)
344            {
345               ((IStateManager) this._inputAttributesState).TrackViewState();
346            }
347            if (this._labelAttributesState != null)
348            {
349                ((IStateManager)this._labelAttributesState).TrackViewState();
350            }
351        }
352
353
354        [DefaultValue(false), Category("Behavior"), Description("CheckBox_AutoPostBack"), Themeable(false)]
355        public virtual bool AutoPostBack
356        {
357            get
358            {
359                object obj1 = this.ViewState["AutoPostBack"];
360                if (obj1 != null)
361                {
362                    return (bool) obj1;
363                }
364                return false;
365            }
366            set
367            {
368                this.ViewState["AutoPostBack"] = value;
369            }
370        }
371
372        [DefaultValue(false), Themeable(false), Category("Behavior"), Description("AutoPostBackControl_CausesValidation")]
373        public virtual bool CausesValidation
374        {
375            get
376            {
377                object obj1 = this.ViewState["CausesValidation"];
378                if (obj1 != null)
379                {
380                    return (bool) obj1;
381                }
382                return false;
383            }
384            set
385            {
386                this.ViewState["CausesValidation"] = value;
387            }
388        }
389
390        [Description("CheckBox_Checked"), Bindable(true, BindingDirection.TwoWay), DefaultValue(false), Themeable(false)]
391        public virtual bool Checked
392        {
393            get
394            {
395                object obj1 = this.ViewState["Checked"];
396                if (obj1 != null)
397                {
398                    return (bool) obj1;
399                }
400                return false;
401            }
402            set
403            {
404                this.ViewState["Checked"] = value;
405            }
406        }
407
408        [Browsable(false), Description("CheckBox_InputAttributes"), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
409        public System.Web.UI.AttributeCollection InputAttributes
410        {
411            get
412            {
413                if (this._inputAttributes == null)
414                {
415                    if (this._inputAttributesState == null)
416                    {
417                        this._inputAttributesState = new StateBag(true);
418                        if (base.IsTrackingViewState)
419                        {
420                            ((IStateManager)this._inputAttributesState).TrackViewState();
421                        }
422                    }
423                    this._inputAttributes = new System.Web.UI.AttributeCollection(this._inputAttributesState);
424                }
425                return this._inputAttributes;
426            }
427        }
428
429        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), Description("CheckBox_LabelAttributes"), Browsable(false)]
430        public System.Web.UI.AttributeCollection LabelAttributes
431        {
432            get
433            {
434                if (this._labelAttributes == null)
435                {
436                    if (this._labelAttributesState == null)
437                    {
438                        this._labelAttributesState = new StateBag(true);
439                        if (base.IsTrackingViewState)
440                        {
441                            ((IStateManager)this._labelAttributesState).TrackViewState();
442                        }
443                    }
444                    this._labelAttributes = new System.Web.UI.AttributeCollection(this._labelAttributesState);
445                }
446                return this._labelAttributes;
447            }
448        }
449
450        //protected override bool RequiresLegacyRendering
451        //{
452        //    get
453        //    {
454        //        return true;
455        //    }
456        //}
457
458        [Bindable(true), Localizable(true), Description("CheckBox_Text"), Category("Appearance"), DefaultValue("")]
459        public virtual string Text
460        {
461            get
462            {
463                string text1 = (string) this.ViewState["Text"];
464                if (text1 != null)
465                {
466                    return text1;
467                }
468                return string.Empty;
469            }
470            set
471            {
472                this.ViewState["Text"] = value;
473            }
474        }
475
476        [DefaultValue(2), Category("Appearance"), Description("WebControl_TextAlign")]
477        public virtual System.Web.UI.WebControls.TextAlign TextAlign
478        {
479            get
480            {
481                object obj1 = this.ViewState["TextAlign"];
482                if (obj1 != null)
483                {
484                    return (System.Web.UI.WebControls.TextAlign) obj1;
485                }
486                return System.Web.UI.WebControls.TextAlign.Right;
487            }
488            set
489            {
490                if ((value < System.Web.UI.WebControls.TextAlign.Left) || (value > System.Web.UI.WebControls.TextAlign.Right))
491                {
492                    throw new ArgumentOutOfRangeException("value");
493                }
494                this.ViewState["TextAlign"] = value;
495            }
496        }
497
498        [DefaultValue(""), Themeable(false), Category("Behavior"), Description("PostBackControl_ValidationGroup")]
499        public virtual string ValidationGroup
500        {
501            get
502            {
503                string text1 = (string) this.ViewState["ValidationGroup"];
504                if (text1 != null)
505                {
506                    return text1;
507                }
508                return string.Empty;
509            }
510            set
511            {
512                this.ViewState["ValidationGroup"] = value;
513            }
514        }
515
516
517        internal System.Web.UI.AttributeCollection _inputAttributes;
518        private StateBag _inputAttributesState;
519        private System.Web.UI.AttributeCollection _labelAttributes;
520        private StateBag _labelAttributesState;
521        private string _valueAttribute;
522        private static readonly object EventCheckedChanged;
523    }
524}
525
526