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：

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

[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

static InventCheckBox()
30

{
31

InventCheckBox.EventCheckedChanged = new object();
32

}
33

public InventCheckBox() : base(HtmlTextWriterTag.Input)
35

{
36

}
37

protected override void AddAttributesToRender(HtmlTextWriter writer)
39

{
40

//base.AddDisplayInlineBlockIfNeeded(writer);
41

}
42

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

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

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

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

posted on 2006-07-07 18:54 KUDO 阅读(444) 评论(0) 编辑收藏举报

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