以上代码中，通过e.detail.value[0]拿到单个todo项里面checkbox的值，通过该值来判断todo的complete状态。最后在updateData的内部，还会通过setData方法，刷新model的内容。只有这样，在toggle操作之后，app底部的统计信息才会更新。
5. 事件绑定的时候，无法传递参数，只能传递一个event。比如上面那个toggle的操作，我其实很想在回调里面把当前todo的id传到这个回调里面，但是想尽办法都做不到，最后只能通过id的方式来处理：就是在wxml中绑定事件的组件上面，加一个id，这个id全page也不能重复，所以id得加前缀，然后在id最后加上todo的id值；当事件触发的时候，通过e.currentTarget.id就能拿到该组件的id，去掉相应的id前缀，就得到todo的id值了。这是目前用到的一个方法，我认为不是很优雅，希望后面能发现更好的办法来实现。
6. app中考虑到了loading的效果，要利用button组件的loading属性来实现。但是loading仅仅是一个样式的控制，它不会控制这个按钮是否能重复点击。所以还要利用buttong的disabled属性，防止重复点击。
剩下的实现细节，都在下面两个文件的源码中，欢迎大家指出其中的问题。
index.wxml的源码：
<!--list.wxml--> <view> <view> <view> <input value="{{newTodoText}}" auto-focus bindinput="newTodoTextInput"/> </view> <button type="primary" size="mini" bindtap="addOne" loading="{{addOneLoading}}" disabled="{{addOneLoading}}"> + Add </button> </view> <view > <view wx:for="{{todos}}" wx:for-item="todo"> <view wx-if="{{!todo.editing}}"> <checkbox-group bindchange="toggleTodo"> <label> <checkbox value="1" checked="{{todo.complete}}"/> </label> </checkbox-group> </view> <view wx-if="{{!todo.editing}}" bindlongtap="startEdit"> <text>{{todo.text}}</text> </view> <view wx-if="{{!todo.editing}}"> <button bindtap="clearSingle" type="warn" size="mini" loading="{{todo.loading}}" disabled="{{todo.loading}}"> Clear </button> </view> <input value="{{todo.text}}" auto-focus bindblur="endEditTodo" wx-if="{{todo.editing}}"/> </view> </view> <view wx:if="{{todos.length > 0}}"> <view> <checkbox-group bindchange="toggleAll"> <label> <checkbox value="1" checked="{{todosOfUncomplted.length == 0}}"/> </label> </checkbox-group> <text>{{todosOfUncomplted.length}} left.</text> </view> <view wx:if="{{todosOfComplted.length > 0}}"> <button type="warn" size="mini" bindtap="clearAll" loading="{{clearAllLoading}}" disabled="{{clearAllLoading}}"> Clear {{todosOfComplted.length}} of done. </button> </view> </view> <loading hidden="{{loadingHidden}}" bindchange="loadingChange"> {{loadingText}} </loading> <toast hidden="{{toastHidden}}" bindchange="toastChange"> {{toastText}} </toast> </view>
index.js的源码：
var app = getApp(); Page( { data: { todos: [], todosOfUncomplted: [], todosOfComplted: [], newTodoText: '', addOneLoading: false, loadingHidden: true, loadingText: '', toastHidden: true, toastText: '', clearAllLoading: false }, updateData: function( resetTodos ) { var data = {}; if( resetTodos ) { data.todos = this.data.todos; } data.todosOfUncomplted = this.data.todos.filter( function( t ) { return !t.complete; }); data.todosOfComplted = this.data.todos.filter( function( t ) { return t.complete; }); this.setData( data ); }, updateStorage: function() { var storage = []; this.data.todos.forEach( function( t ) { storage.push( { id: t.id, text: t.text, complete: t.complete }) }); wx.setStorageSync( 'todos', storage ); }, onLoad: function() { this.setData( { todos: wx.getStorageSync( 'todos' ) || [] }); this.updateData( false ); }, getTodo: function( id ) { return this.data.todos.filter( function( t ) { return id == t.id; })[ 0 ]; }, getTodoId: function( e, prefix ) { return e.currentTarget.id.substring( prefix.length ); }, toggleTodo: function( e ) { var id = this.getTodoId( e, 'todo-item-chk-' ); var value = e.detail.value[ 0 ]; var complete = !!value; var todo = this.getTodo( id ); todo.complete = complete; this.updateData( true ); this.updateStorage(); }, toggleAll: function( e ) { var value = e.detail.value[ 0 ]; var complete = !!value; this.data.todos.forEach( function( t ) { t.complete = complete; }); this.updateData( true ); this.updateStorage(); }, clearTodo: function( id ) { var targetIndex; this.data.todos.forEach( function( t, i ) { if( targetIndex !== undefined ) return; if( t.id == id ) { targetIndex = i; } }); this.data.todos.splice( targetIndex, 1 ); }, clearSingle: function( e ) { var id = this.getTodoId( e, 'btn-del-item-' ); var todo = this.getTodo( id ); todo.loading = true; this.updateData( true ); var that = this; setTimeout( function() { that.clearTodo( id ); that.updateData( true ); that.updateStorage(); }, 500 ); }, clearAll: function() { this.setData( { clearAllLoading: true }); var that = this; setTimeout( function() { that.data.todosOfComplted.forEach( function( t ) { that.clearTodo( t.id ); }); that.setData( { clearAllLoading: false }); that.updateData( true ); that.updateStorage(); that.setData( { toastHidden: false, toastText: 'Success' }); }, 500 ); }, startEdit: function( e ) { var id = this.getTodoId( e, 'todo-item-txt-' ); var todo = this.getTodo( id ); todo.editing = true; this.updateData( true ); this.updateStorage(); }, newTodoTextInput: function( e ) { this.setData( { newTodoText: e.detail.value }); }, endEditTodo: function( e ) { var id = this.getTodoId( e, 'todo-item-edit-' ); var todo = this.getTodo( id ); todo.editing = false; todo.text = e.detail.value; this.updateData( true ); this.updateStorage(); }, addOne: function( e ) { if( !this.data.newTodoText ) return; this.setData( { addOneLoading: true }); //open loading this.setData( { loadingHidden: false, loadingText: 'Waiting...' }); var that = this; setTimeout( function() { //close loading and toggle button loading status that.setData( { loadingHidden: true, addOneLoading: false, loadingText: '' }); that.data.todos.push( { id: app.getId(), text: that.data.newTodoText, compelte: false }); that.setData( { newTodoText: '' }); that.updateData( true ); that.updateStorage(); }, 500 ); }, loadingChange: function() { this.setData( { loadingHidden: true, loadingText: '' }); }, toastChange: function() { this.setData( { toastHidden: true, toastText: '' }); } });