json实现通用的下拉框

⑴ Extjs怎么实现下拉框多选

1、扩展js类库，在项目中建立一个 js文件，命名为:xxx.js 其代码为

if('function'!==typeofRegExp.escape)
{
RegExp.escape=function(s)
{
if('string'!==typeofs)
{
returns;
}
returns.replace(/([.*+?^=!:${}()|[]/\])/g,'\$1');
};
}

Ext.ns('Ext.form');

Ext.form.MultiSelect=Ext.extend(Ext.form.ComboBox,
{
checkField:'checked',
multi:true,
separator:',',
initComponent:function()
{
if(!this.tpl)
{
this.tpl='<tplfor=".">'+'<divclass="x-combo-list-item">'
+'<imgsrc="'+Ext.BLANK_IMAGE_URL+'"'
+'class="ux-MultiSelect-iconux-MultiSelect-icon-'
+'{[values.'+this.checkField+'?"checked":"unchecked"'
+']}">'
+'{[values.'+this.displayField+']}'
+'</div>'
+'</tpl>';
}

Ext.form.MultiSelect.superclass.initComponent.apply(this,arguments);

this.on(
{
scope:this,
beforequery:this.onBeforeQuery,
blur:this.onRealBlur
});

this.onLoad=this.onLoad.createSequence(function()
{
if(this.el)
{
varv=this.el.dom.value;
this.el.dom.value='';
this.el.dom.value=v;
}
});
},
initEvents:function()
{
Ext.form.MultiSelect.superclass.initEvents.apply(this,arguments);
this.keyNav.tab=false;
},
beforeBlur:function()
{
},
postBlur:function()
{
},

clearValue:function()
{
this.value='';
this.setRawValue(this.value);
this.store.clearFilter();
this.store.each(function(r)
{
r.set(this.checkField,false);
},this);
if(this.hiddenField)
{
this.hiddenField.value='';
}
this.applyEmptyText();
},
getCheckedDisplay:function()
{
varre=newRegExp(this.separator,"g");
returnthis.getCheckedValue(this.displayField).replace(re,this.separator+'');
},
getCheckedValue:function(field)
{
field=field||this.valueField;
varc=[];
varsnapshot=this.store.snapshot||this.store.data;
snapshot.each(function(r)
{
if(r.get(this.checkField))
{
c.push(r.get(field));
}
},this);

returnc.join(this.separator);
},
onBeforeQuery:function(qe)
{
qe.query=qe.query.replace(newRegExp(RegExp.escape(this.getCheckedDisplay())+'['+this.separator+']*'),'');
},
onRealBlur:function()
{
this.list.hide();
varrv=this.getRawValue();
varrva=rv.split(newRegExp(RegExp.escape(this.separator)+'*'));
varva=[];
varsnapshot=this.store.snapshot||this.store.data;

Ext.each(rva,function(v)
{
snapshot.each(function(r)
{
if(v===r.get(this.displayField))
{
va.push(r.get(this.valueField));
}
},this);
},this);
this.setValue(va.join(this.separator));
this.store.clearFilter();
},
onSelect:function(record,index)
{
if(this.fireEvent('beforeselect',this,record,index)!==false)
{
record.set(this.checkField,!record.get(this.checkField));

if(this.store.isFiltered())
{
this.doQuery(this.allQuery);
}

if(this.multi)
{
if(record.get("key")=="---"&&record.get(this.checkField))
{
this.setValue("---");
}
else
{
this.setValue(this.getCheckedValue());
}
}
else
{
this.clearValue();
this.value=record.get(this.valueField);
this.setRawValue(record.get(this.displayField));
this.list.hide();
}

this.fireEvent('select',this,record,index);
}
},
setValue:function(v)
{
if(v)
{
v=''+v;
if(this.valueField)
{
this.store.clearFilter();
this.store.each(function(r)
{
varchecked=!(!v.match('(^|'+this.separator+')'
+RegExp.escape(r.get(this.valueField))
+'('+this.separator+'|$)'));
r.set(this.checkField,checked);
},this);
this.value=this.getCheckedValue();
this.setRawValue(this.getCheckedDisplay());
if(this.hiddenField)
{
this.hiddenField.value=this.value;
}
}
else
{
this.value=v;
this.setRawValue(v);
if(this.hiddenField)
{
this.hiddenField.value=v;
}
}
if(this.el)
{
this.el.removeClass(this.emptyClass);
}
}
else
{
this.clearValue();
}
},
selectAll:function()
{
this.store.each(function(record)
{
record.set(this.checkField,true);
},this);
this.doQuery(this.allQuery);
this.setValue(this.getCheckedValue());
},
deselectAll:function()
{
this.clearValue();
}
});
Ext.reg('multiSelect',Ext.form.MultiSelect);

2、在ext-all.css文件最后，加入css样式

.ux-MultiSelect-icon{width:16px;height:16px;float:left;background-position:-1px-1px!important;background-repeat:no-repeat!important;}
.ux-MultiSelect-icon-checked{background:transparenturl(../images/default/menu/checked.gif);}
.ux-MultiSelect-icon-unchecked{background:transparenturl(../images/default/menu/unchecked.gif);}

3、使用

varDepartUserStore=newExt.data.Store(
{
proxy:newExt.data.HttpProxy(
{
url:'/Web/Manage/DeskTop/JSON/ScheleManager/GetSimpleDepartUserInfo.aspx'
}),
//读取Json
reader:newExt.data.JsonReader(
{totalProperty:"totalCount",root:"root"},
[
{name:'UserId',type:'int'},
{name:'UserName',type:'string'}
])
});

varDepartUserCbox=newExt.form.MultiSelect(
{
fieldLabel:'姓名',
labelStyle:'width:80px',
width:150,
editable:false,
id:'DepartUserDS',
hiddenName:'DepartUserIdDS',
store:DepartUserStore,
emptyText:'--请选择--',
allowBlank:false,
blankText:'请选择',
mode:'remote',
displayField:'UserName',
valueField:'UserId',
triggerAction:'all',
selectOnFocus:true,
listWidth:200
});

DepartUserStore.on('load',function()
{
DepartUserCbox.selectAll();//全选
});

DepartUserStore.load();

⑵ js拼接实现下拉列表框

思路：

1. 如果下拉菜单是options 。

   你可以使用for循环，创建options，然后添加text ，value和一些属性内。最后放到select标签里。

2. 如果你容是用其他标签模拟的下拉菜单。和上面的方法是一样的，只是你要自己写样式。