NavigationView 是官方根据Container控件扩展而来的，由一个导航栏和一个card组成，具备导航和返回时自动销毁当前界面的功能，非常适合新手使用。
其中导航栏的代码如下：
1 Ext.define('Ext.navigation.Bar', {
2 extend: 'Ext.TitleBar',
3 requires: ['Ext.Button', 'Ext.Spacer'],
4 isToolbar: true,
5 config: {
6 baseCls: Ext.baseCSSPrefix + 'toolbar',
7 cls: Ext.baseCSSPrefix + 'navigation-bar',
8 ui: 'dark',
9 title: null,
10 defaultType: 'button',
11 layout: {
12 type: 'hbox'
13 },
14 defaultBackButtonText: 'Back',
15 animation: {
16 duration: 300
17 },
18 useTitleForBackButtonText: null,
19 view: null,
20 android2Transforms: false,
21 backButton: {
22 align: 'left',
23 ui: 'back',
24 hidden: true
25 }
26 },
27 platformConfig: [{
28 theme: ['Blackberry'],
29 animation: false
30 }],
31 constructor: function(config) {
32 config = config || {};
33 if (!config.items) {
34 config.items = []
35 }
36 this.backButtonStack = [];
37 this.activeAnimations = [];
38 this.callParent([config])
39 },
40 applyBackButton: function(config) {
41 return Ext.factory(config, Ext.Button, this.getBackButton())
42 },
43 updateBackButton: function(newBackButton, oldBackButton) {
44 if (oldBackButton) {
45 this.remove(oldBackButton)
46 }
47 if (newBackButton) {
48 this.add(newBackButton);
49 newBackButton.on({
50 scope: this,
51 tap: this.onBackButtonTap
52 })
53 }
54 },
55 onBackButtonTap: function() {
56 this.fireEvent('back', this)
57 },
58 updateView: function(newView) {
59 var me = this,
60 backButton = me.getBackButton(),
61 innerItems,
62 i,
63 backButtonText,
64 item,
65 title,
66 titleText;
67 me.getItems();
68 if (newView) {
69 innerItems = newView.getInnerItems();
70 for (i = 0; i < innerItems.length; i++) {
71 item = innerItems[i];
72 title = (item.getTitle) ? item.getTitle() : item.config.title;
73 me.backButtonStack.push(title || ' ')
74 }
75 titleText = me.getTitleText();
76 if (titleText === undefined) {
77 titleText = ''
78 }
79 me.setTitle(titleText);
80 backButtonText = me.getBackButtonText();
81 if (backButtonText) {
82 backButton.setText(backButtonText);
83 backButton.show()
84 }
85 }
86 },
87 onViewAdd: function(view, item) {
88 var me = this,
89 backButtonStack = me.backButtonStack,
90 hasPrevious, title;
91 me.endAnimation();
92 title = (item.getTitle) ? item.getTitle() : item.config.title;
93 backButtonStack.push(title || ' ');
94 hasPrevious = backButtonStack.length > 1;
95 me.doChangeView(view, hasPrevious, false)
96 },
97 onViewRemove: function(view) {
98 var me = this,
99 backButtonStack = me.backButtonStack,
100 hasPrevious;
101 me.endAnimation();
102 backButtonStack.pop();
103 hasPrevious = backButtonStack.length > 1;
104 me.doChangeView(view, hasPrevious, true)
105 },
106 doChangeView: function(view, hasPrevious, reverse) {
107 var me = this,
108 leftBox = me.leftBox,
109 leftBoxElement = leftBox.element,
110 titleComponent = me.titleComponent,
111 titleElement = titleComponent.element,
112 backButton = me.getBackButton(),
113 titleText = me.getTitleText(),
114 backButtonText = me.getBackButtonText(),
115 animation = me.getAnimation() && view.getLayout().getAnimation(),
116 animated = animation && animation.isAnimation && view.isPainted(),
117 properties,
118 leftGhost,
119 titleGhost,
120 leftProps,
121 titleProps;
122 if (animated) {
123 leftGhost = me.createProxy(leftBox.element);
124 leftBoxElement.setStyle('opacity', '0');
125 backButton.setText(backButtonText);
126 backButton[hasPrevious ? 'show': 'hide']();
127 titleGhost = me.createProxy(titleComponent.element.getParent());
128 titleElement.setStyle('opacity', '0');
129 me.setTitle(titleText);
130 properties = me.measureView(leftGhost, titleGhost, reverse);
131 leftProps = properties.left;
132 titleProps = properties.title;
133 me.isAnimating = true;
134 me.animate(leftBoxElement, leftProps.element);
135 me.animate(titleElement, titleProps.element,
136 function() {
137 titleElement.setLeft(properties.titleLeft);
138 me.isAnimating = false;
139 me.refreshTitlePosition()
140 });
141 if (Ext.browser.is.AndroidStock2 && !this.getAndroid2Transforms()) {
142 leftGhost.ghost.destroy();
143 titleGhost.ghost.destroy()
144 } else {
145 me.animate(leftGhost.ghost, leftProps.ghost);
146 me.animate(titleGhost.ghost, titleProps.ghost,
147 function() {
148 leftGhost.ghost.destroy();
149 titleGhost.ghost.destroy()
150 })
151 }
152 } else {
153 if (hasPrevious) {
154 backButton.setText(backButtonText);
155 backButton.show()
156 } else {
157 backButton.hide()
158 }
159 me.setTitle(titleText)
160 }
161 },
162 measureView: function(oldLeft, oldTitle, reverse) {
163 var me = this,
164 barElement = me.element,
165 newLeftElement = me.leftBox.element,
166 titleElement = me.titleComponent.element,
167 minOffset = Math.min(barElement.getWidth() / 3, 200),
168 newLeftWidth = newLeftElement.getWidth(),
169 barX = barElement.getX(),
170 barWidth = barElement.getWidth(),
171 titleX = titleElement.getX(),
172 titleLeft = titleElement.getLeft(),
173 titleWidth = titleElement.getWidth(),
174 oldLeftX = oldLeft.x,
175 oldLeftWidth = oldLeft.width,
176 oldLeftLeft = oldLeft.left,
177 useLeft = Ext.browser.is.AndroidStock2 && !this.getAndroid2Transforms(),
178 newOffset,
179 oldOffset,
180 leftAnims,
181 titleAnims,
182 omega,
183 theta;
184 theta = barX - oldLeftX - oldLeftWidth;
185 if (reverse) {
186 newOffset = theta;
187 oldOffset = Math.min(titleX - oldLeftWidth, minOffset)
188 } else {
189 oldOffset = theta;
190 newOffset = Math.min(titleX - barX, minOffset)
191 }
192 if (useLeft) {
193 leftAnims = {
194 element: {
195 from: {
196 left: newOffset,
197 opacity: 1
198 },
199 to: {
200 left: 0,
201 opacity: 1
202 }
203 }
204 }
205 } else {
206 leftAnims = {
207 element: {
208 from: {
209 transform: {
210 translateX: newOffset
211 },
212 opacity: 0
213 },
214 to: {
215 transform: {
216 translateX: 0
217 },
218 opacity: 1
219 }
220 },
221 ghost: {
222 to: {
223 transform: {
224 translateX: oldOffset
225 },
226 opacity: 0
227 }
228 }
229 }
230 }
231 theta = barX - titleX + newLeftWidth;
232 if ((oldLeftLeft + titleWidth) > titleX) {
233 omega = barX - titleX - titleWidth
234 }
235 if (reverse) {
236 titleElement.setLeft(0);
237 oldOffset = barX + barWidth - titleX - titleWidth;
238 if (omega !== undefined) {
239 newOffset = omega
240 } else {
241 newOffset = theta
242 }
243 } else {
244 newOffset = barX + barWidth - titleX - titleWidth;
245 if (omega !== undefined) {
246 oldOffset = omega
247 } else {
248 oldOffset = theta
249 }
250 newOffset = Math.max(titleLeft, newOffset)
251 }
252 if (useLeft) {
253 titleAnims = {
254 element: {
255 from: {
256 left: newOffset,
257 opacity: 1
258 },
259 to: {
260 left: titleLeft,
261 opacity: 1
262 }
263 }
264 }
265 } else {
266 titleAnims = {
267 element: {
268 from: {
269 transform: {
270 translateX: newOffset
271 },
272 opacity: 0
273 },
274 to: {
275 transform: {
276 translateX: titleLeft
277 },
278 opacity: 1
279 }
280 },
281 ghost: {
282 to: {
283 transform: {
284 translateX: oldOffset
285 },
286 opacity: 0
287 }
288 }
289 }
290 }
291 return {
292 left: leftAnims,
293 title: titleAnims,
294 titleLeft: titleLeft
295 }
296 },
297 animate: function(element, config, callback) {
298 var me = this,
299 animation;
300 element.setLeft(0);
301 config = Ext.apply(config, {
302 element: element,
303 easing: 'ease-in-out',
304 duration: me.getAnimation().duration || 250,
305 preserveEndState: true
306 });
307 animation = new Ext.fx.Animation(config);
308 animation.on('animationend',
309 function() {
310 if (callback) {
311 callback.call(me)
312 }
313 },
314 me);
315 Ext.Animator.run(animation);
316 me.activeAnimations.push(animation)
317 },
318 endAnimation: function() {
319 var activeAnimations = this.activeAnimations,
320 animation, i, ln;
321 if (activeAnimations) {
322 ln = activeAnimations.length;
323 for (i = 0; i < ln; i++) {
324 animation = activeAnimations[i];
325 if (animation.isAnimating) {
326 animation.stopAnimation()
327 } else {
328 animation.destroy()
329 }
330 }
331 this.activeAnimations = []
332 }
333 },
334 refreshTitlePosition: function() {
335 if (!this.isAnimating) {
336 this.callParent()
337 }
338 },
339 getBackButtonText: function() {
340 var text = this.backButtonStack[this.backButtonStack.length - 2],
341 useTitleForBackButtonText = this.getUseTitleForBackButtonText();
342 if (!useTitleForBackButtonText) {
343 if (text) {
344 text = this.getDefaultBackButtonText()
345 }
346 }
347 return text
348 },
349 getTitleText: function() {
350 return this.backButtonStack[this.backButtonStack.length - 1]
351 },
352 beforePop: function(count) {
353 count--;
354 for (var i = 0; i < count; i++) {
355 this.backButtonStack.pop()
356 }
357 },
358 doSetHidden: function(hidden) {
359 if (!hidden) {
360 this.element.setStyle({
361 position: 'relative',
362 top: 'auto',
363 left: 'auto',
364 width: 'auto'
365 })
366 } else {
367 this.element.setStyle({
368 position: 'absolute',
369 top: '-1000px',
370 left: '-1000px',
371 width: this.element.getWidth() + 'px'
372 })
373 }
374 },
375 createProxy: function(element) {
376 var ghost, x, y, left, width;
377 ghost = element.dom.cloneNode(true);
378 ghost.id = element.id + '-proxy';
379 element.getParent().dom.appendChild(ghost);
380 ghost = Ext.get(ghost);
381 x = element.getX();
382 y = element.getY();
383 left = element.getLeft();
384 width = element.getWidth();
385 ghost.setStyle('position', 'absolute');
386 ghost.setX(x);
387 ghost.setY(y);
388 ghost.setHeight(element.getHeight());
389 ghost.setWidth(width);
390 return {
391 x: x,
392 y: y,
393 left: left,
394 width: width,
395 ghost: ghost
396 }
397 }
398 });
可以看出他是继承于一个TitleBar，中间为标题，左侧有一个默认的返回按钮这些代码看似复杂，其实逻辑很简单。
他的主要作用就是监听返回按钮，为其添加一个back自定义事件。并且通过this.backButtonStack这个数组来储存标题显示记录。
在返回时动态更新标题栏，并且有切换的动画效果。由于标题长短不一，所以整个导航栏的代码大部分都是来处理切换动画了。
实际上它的核心方法只有：
constructor：进行配置的初始化处理
applyBackButton：动态创建返回按钮
updateBackButton：动态更新返回按钮，并且添加监听（触发）
onBackButtonTap：将返回按钮的点击转换为自定义事件back
updateView：更新导航栏按钮，标题。NavigationView中更新视图时会触发它
onViewAdd：添加新的历史记录。NavigationView中添加新的视图时会触发它
onViewRemove：移除当前的历史记录，NavigationView中移除视图时会触发它
doChangeView：视图改变后处理标题，返回按钮。大部分代码其实是处理切换动画效果
getBackButtonText：获取返回按钮的text值，如果useTitleForBackButtonText为ture就需要它来处理
getTitleText：获取最后一个标题
beforePop：点返回按钮时处理this.backButtonStack这个数组
我们如果想要重写它可以注意这些方法，其他的都是用来处理动画效果的。个人觉得没必要有这些方法，会影响性能
NavigationView代码如下：
1 Ext.define('Ext.navigation.View', {
2 extend: 'Ext.Container',
3 alternateClassName: 'Ext.NavigationView',
4 xtype: 'navigationview',
5 requires: ['Ext.navigation.Bar'],
6 config: {
7 baseCls: Ext.baseCSSPrefix + 'navigationview',
8 navigationBar: {
9 docked: 'top'
10 },
11 defaultBackButtonText: 'Back',
12 useTitleForBackButtonText: false,
13 layout: {
14 type: 'card',
15 animation: {
16 duration: 300,
17 easing: 'ease-out',
18 type: 'slide',
19 direction: 'left'
20 }
21 }
22 },
23 platformConfig: [{
24 theme: ['Blackberry'],
25 navigationBar: {
26 splitNavigation: true
27 }
28 }],
29 initialize: function() {
30 var me = this,
31 navBar = me.getNavigationBar();
32 if (navBar) {
33 navBar.on({
34 back: me.onBackButtonTap,
35 scope: me
36 });
37 me.relayEvents(navBar, 'rightbuttontap');
38 me.relayEvents(me, {
39 add: 'push',
40 remove: 'pop'
41 })
42 }
43 var layout = me.getLayout();
44 if (layout && !layout.isCard) {
45 Ext.Logger.error('The base layout for a NavigationView must always be a Card Layout')
46 }
47 },
48 applyLayout: function(config) {
49 config = config || {};
50 return config
51 },
52 onBackButtonTap: function() {
53 this.pop();
54 this.fireEvent('back', this)
55 },
56 push: function(view) {
57 return this.add(view)
58 },
59 pop: function(count) {
60 if (this.beforePop(count)) {
61 return this.doPop()
62 }
63 },
64 beforePop: function(count) {
65 var me = this,
66 innerItems = me.getInnerItems();
67 if (Ext.isString(count) || Ext.isObject(count)) {
68 var last = innerItems.length - 1,
69 i;
70 for (i = last; i >= 0; i--) {
71 if ((Ext.isString(count) && Ext.ComponentQuery.is(innerItems[i], count)) || (Ext.isObject(count) && count == innerItems[i])) {
72 count = last - i;
73 break
74 }
75 }
76 if (!Ext.isNumber(count)) {
77 return false
78 }
79 }
80 var ln = innerItems.length,
81 toRemove;
82 if (!Ext.isNumber(count) || count < 1) {
83 count = 1
84 }
85 count = Math.min(count, ln - 1);
86 if (count) {
87 me.getNavigationBar().beforePop(count);
88 toRemove = innerItems.splice( - count, count - 1);
89 for (i = 0; i < toRemove.length; i++) {
90 this.remove(toRemove[i])
91 }
92 return true
93 }
94 return false
95 },
96 doPop: function() {
97 var me = this,
98 innerItems = this.getInnerItems();
99 me.remove(innerItems[innerItems.length - 1]);
100 if (innerItems.length < 3 && this.$backButton) {
101 this.$backButton.hide()
102 }
103 if (this.$titleContainer) {
104 if (!this.$titleContainer.setTitle) {
105 Ext.Logger.error('You have selected to display a title in a component that does not support titles in NavigationView. Please remove the `title` configuration from your NavigationView item, or change it to a component that has a `setTitle` method.')
106 }
107 var item = innerItems[innerItems.length - 2];
108 this.$titleContainer.setTitle((item.getTitle) ? item.getTitle() : item.config.title)
109 }
110 return this.getActiveItem()
111 },
112 getPreviousItem: function() {
113 var innerItems = this.getInnerItems();
114 return innerItems[innerItems.length - 2]
115 },
116 updateUseTitleForBackButtonText: function(useTitleForBackButtonText) {
117 var navigationBar = this.getNavigationBar();
118 if (navigationBar) {
119 navigationBar.setUseTitleForBackButtonText(useTitleForBackButtonText)
120 }
121 },
122 updateDefaultBackButtonText: function(defaultBackButtonText) {
123 var navigationBar = this.getNavigationBar();
124 if (navigationBar) {
125 navigationBar.setDefaultBackButtonText(defaultBackButtonText)
126 }
127 },
128 applyNavigationBar: function(config) {
129 if (!config) {
130 config = {
131 hidden: true,
132 docked: 'top'
133 }
134 }
135 if (config.title) {
136 delete config.title;
137 Ext.Logger.warn("Ext.navigation.View: The 'navigationBar' configuration does not accept a 'title' property. You set the title of the navigationBar by giving this navigation view's children a 'title' property.")
138 }
139 config.view = this;
140 config.useTitleForBackButtonText = this.getUseTitleForBackButtonText();
141 if (config.splitNavigation) {
142 this.$titleContainer = this.add({
143 docked: 'top',
144 xtype: 'titlebar',
145 ui: 'light',
146 title: this.$currentTitle || ''
147 });
148 var containerConfig = (config.splitNavigation === true) ? {}: config.splitNavigation;
149 this.$backButtonContainer = this.add(Ext.apply({
150 xtype: 'toolbar',
151 docked: 'bottom'
152 },
153 containerConfig));
154 this.$backButton = this.$backButtonContainer.add({
155 xtype: 'button',
156 text: 'Back',
157 hidden: true,
158 ui: 'back'
159 });
160 this.$backButton.on({
161 scope: this,
162 tap: this.onBackButtonTap
163 });
164 config = {
165 hidden: true,
166 docked: 'top'
167 }
168 }
169 return Ext.factory(config, Ext.navigation.Bar, this.getNavigationBar())
170 },
171 updateNavigationBar: function(newNavigationBar, oldNavigationBar) {
172 if (oldNavigationBar) {
173 this.remove(oldNavigationBar, true)
174 }
175 if (newNavigationBar) {
176 this.add(newNavigationBar)
177 }
178 },
179 applyActiveItem: function(activeItem, currentActiveItem) {
180 var me = this,
181 innerItems = me.getInnerItems();
182 me.getItems();
183 if (!me.initialized) {
184 activeItem = innerItems.length - 1
185 }
186 return this.callParent([activeItem, currentActiveItem])
187 },
188 doResetActiveItem: function(innerIndex) {
189 var me = this,
190 innerItems = me.getInnerItems(),
191 animation = me.getLayout().getAnimation();
192 if (innerIndex > 0) {
193 if (animation && animation.isAnimation) {
194 animation.setReverse(true)
195 }
196 me.setActiveItem(innerIndex - 1);
197 me.getNavigationBar().onViewRemove(me, innerItems[innerIndex], innerIndex)
198 }
199 },
200 doRemove: function() {
201 var animation = this.getLayout().getAnimation();
202 if (animation && animation.isAnimation) {
203 animation.setReverse(false)
204 }
205 this.callParent(arguments)
206 },
207 onItemAdd: function(item, index) {
208 if (item && item.getDocked() && item.config.title === true) {
209 this.$titleContainer = item
210 }
211 this.doItemLayoutAdd(item, index);
212 var navigaitonBar = this.getInitialConfig().navigationBar;
213 if (!this.isItemsInitializing && item.isInnerItem()) {
214 this.setActiveItem(item);
215 if (navigaitonBar) {
216 this.getNavigationBar().onViewAdd(this, item, index)
217 }
218 if (this.$backButtonContainer) {
219 this.$backButton.show()
220 }
221 }
222 if (item && item.isInnerItem()) {
223 this.updateTitleContainerTitle((item.getTitle) ? item.getTitle() : item.config.title)
224 }
225 if (this.initialized) {
226 this.fireEvent('add', this, item, index)
227 }
228 },
229 updateTitleContainerTitle: function(title) {
230 if (this.$titleContainer) {
231 if (!this.$titleContainer.setTitle) {
232 Ext.Logger.error('You have selected to display a title in a component that does not support titles in NavigationView. Please remove the `title` configuration from your NavigationView item, or change it to a component that has a `setTitle` method.')
233 }
234 this.$titleContainer.setTitle(title)
235 } else {
236 this.$currentTitle = title
237 }
238 },
239 reset: function() {
240 return this.pop(this.getInnerItems().length)
241 }
242 });
这些代码就是核心了，作用如下：
initialize：初始化，为导航栏的返回事件添加监听（触发onBackButtonTap方法），为add和romove方法添加监听
onBackButtonTap：点击返回按钮时触发，触发pop方法，并且添加自定义事件。
push：其实就是调用add方法，添加新视图
pop：会调用beforePop方法和doPop方法
beforePop：有时候不止移除一项，这里的逻辑很复杂
doPop：移除card中最后一项
getPreviousItem：获取倒数第二项
updateUseTitleForBackButtonText：作用顾名思义
updateDefaultBackButtonText：同上
applyNavigationBar：创建导航栏而已，别怕代码多
updateNavigationBar：更新导航栏
applyActiveItem：为什么card始终显示最后一项，就是因为重写了它
doRemove：调用remove方法后会触发也是反转切换动画
onItemAdd：项第一次被添加到card中触发，一系列的逻辑处理
updateTitleContainerTitle：顾名思义
reset：清空所有项，不过这里逻辑比较复杂。会调用pop方法
http://www.cnblogs.com/mlzs/p/3376399.html这里我有对代码进行一些注释，可以参考一下。
下面说说用法，个人推荐先创建一个视图继承它，如下：
1 Ext.define('app.view.Main', {
2 extend: 'Ext.NavigationView',
3 xtype: 'main',
4 config: {
5 navigationBar: {
6 backButton: {
7 iconCls: 'arrow_left',
8 ui: '',
9 cls: 'back'
10 }
11 },
12 cls: 'cardPanel'
13 }
14 });
app.js中初始化它：
1 launch: function () {
2 // Destroy the #appLoadingIndicator element
3 Ext.fly('appLoadingIndicator').destroy();
4 // Initialize the main view
5 Ext.Viewport.add(Ext.create('app.view.Main'));
6 }
单独的main控制层监听它：
1 //引用
2 refs: {
3 main: 'main'
4 }
添加一个路由监听
1 routes: {
2 'redirect/:view': 'showView'
3 }
main控制层中写一个方法：
1 //展示页面
2 showView: function (view, isPop) {
3 var main = this.getMain(),
4 view = Ext.create(xtype);
5 main.push(view, params);
6 }
任何控制层之中都可以通过如下方法触发这个方法
this.redirectTo('redirect/xtype');
当然这个只是简单的用法，有兴趣的可以看看http://www.cnblogs.com/mlzs/p/3498846.html，里面有免费视频听，也可以参考官方的示例。
值得注意的是，NavigationView作为一个容器，虽然是继承于Container，里面的tpl，data，html这些都是不能使用的，他的布局也不能随便更改。