一、不传URL
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var myData={ "Head":[
{ "UserName":"admin","Name":"李亚斌","Gender":"M","Password":"123456","Status":"0","Department":"技术部","Title":"程序员","Email":" 0:00:00","ModifyUser":"1","ModifyTime":"2009-10-30 10:04:22"},
{ "UserName":"00001","Name":"李香兰","Gender":"F","Password":"123456","Status":"0","Department":"技术部","Title":"程序员","Email":" 0:00:00","ModifyUser":"","ModifyTime":""}
]
}
var ds = new Ext.data.Store({
//proxy: new Ext.data.MemoryProxy(myData),
reader: new Ext.data.JsonReader({root: 'Head'},
[{name:'UserName'},{name: 'Name'}, {name:'Gender'},{name:'Password'},{name:'Status'},{name:'Department'},{name:'Title'},{name:'Email'},{name:'OfficePhone'}])
});
ds.loadData(myData)
或者
var ds = new Ext.data.Store({
proxy: new Ext.data.MemoryProxy(myData),
reader: new Ext.data.JsonReader({root: 'Head'},
[{name:'UserName'},{name: 'Name'}, {name:'Gender'},{name:'Password'},{name:'Status'},{name:'Department'},{name:'Title'},{name:'Email'},{name:'OfficePhone'}])
});
//注意下面这句 切记
ds.load()都可以
二、使用URL
(1)JSON HTMLPage.htm页面做数据源
{"Head":[{"appeId":"1","survId":"1","location":"","surveyDate":"2008-03-14","surveyTime":"12:19:47","inputUserId":"1","inputTime":"2008-03-14 12:21:51","modifyTime":"0000-00-00 00:00:00"},{"appeId":"2","survId":"32","location":"","surveyDate":"2008-03-14","surveyTime":"22:43:09","inputUserId":"32","inputTime":"2008-03-14 22:43:37","modifyTime":"0000-00-00 00:00:00"},{"appeId":"3","survId":"32","location":"","surveyDate":"2008-03-15","surveyTime":"07:59:33","inputUserId":"32","inputTime":"2008-03-15 08:00:44","modifyTime":"0000-00-00 00:00:00"},{"appeId":"4","survId":"1","location":"","surveyDate":"2008-03-15","surveyTime":"10:45:42","inputUserId":"1","inputTime":"2008-03-15 10:46:04","modifyTime":"0000-00-00 00:00:00"},{"appeId":"5","survId":"32","location":"","surveyDate":"2008-03-16","surveyTime":"08:04:49","inputUserId":"32","inputTime":"2008-03-16 08:05:26","modifyTime":"0000-00-00 00:00:00"},{"appeId":"6","survId":"32","location":"","surveyDate":"2008-03-20","surveyTime":"20:19:01","inputUserId":"32","inputTime":"2008-03-20 20:19:32","modifyTime":"0000-00-00 00:00:00"}]}
{"Head":[{"appeId":"1","survId":"1","location":"","surveyDate":"2008-03-14","surveyTime":"12:19:47","inputUserId":"1","inputTime":"2008-03-14 12:21:51","modifyTime":"0000-00-00 00:00:00"},{"appeId":"2","survId":"32","location":"","surveyDate":"2008-03-14","surveyTime":"22:43:09","inputUserId":"32","inputTime":"2008-03-14 22:43:37","modifyTime":"0000-00-00 00:00:00"},{"appeId":"3","survId":"32","location":"","surveyDate":"2008-03-15","surveyTime":"07:59:33","inputUserId":"32","inputTime":"2008-03-15 08:00:44","modifyTime":"0000-00-00 00:00:00"},{"appeId":"4","survId":"1","location":"","surveyDate":"2008-03-15","surveyTime":"10:45:42","inputUserId":"1","inputTime":"2008-03-15 10:46:04","modifyTime":"0000-00-00 00:00:00"},{"appeId":"5","survId":"32","location":"","surveyDate":"2008-03-16","surveyTime":"08:04:49","inputUserId":"32","inputTime":"2008-03-16 08:05:26","modifyTime":"0000-00-00 00:00:00"},{"appeId":"6","survId":"32","location":"","surveyDate":"2008-03-20","surveyTime":"20:19:01","inputUserId":"32","inputTime":"2008-03-20 20:19:32","modifyTime":"0000-00-00 00:00:00"}]}
相应的ext代码
Ext.onReady(function(){
var proxy=new Ext.data.HttpProxy({url:'HTMLPage.htm'});
//定义reader
var reader=new Ext.data.JsonReader({ root:'Head' },
[
{name: 'appeId', mapping: 'appeId'},
{name: 'survId'},
{name: 'location'},
{name: 'surveyDate'},
{name: 'surveyTime'},
{name: 'inputUserId'}
]
)
//构建Store
var store=new Ext.data.Store( {
proxy:proxy,
reader:reader
});
//载入
store.load();
// create the grid
var grid = new Ext.grid.GridPanel({
store: store,
columns: [
{header: "appeId", width: 60, dataIndex: 'appeId', sortable: true},
{header: "survId", width: 60, dataIndex: 'survId', sortable: true},
{header: "location", width: 60, dataIndex: 'location', sortable: true},
{header: "surveyDate", width: 100, dataIndex: 'surveyDate', sortable: true},
{header: "surveyTime", width: 100, dataIndex: 'surveyTime', sortable: true},
{header: "inputUserId", width:80, dataIndex: 'inputUserId', sortable: true}
],
renderTo:'example-grid',
width:540,
height:200
});
});
(2).如果json 数据中 没有数据标题"Head“只需要把reader改成 如下即可:其他不需要改变
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//定义reader
var reader=new Ext.data.JsonReader({},
[
{name: 'appeId', mapping: 'appeId'},
{name: 'survId'},
{name: 'location'},
{name: 'surveyDate'},
{name: 'surveyTime'},
{name: 'inputUserId'}
]
)
经验小技巧:传data 的URL文件可为,html,aspx.js等,文件引用的js永远和 文件在同一路径。
另外主要注意一下 HttpProxy 和MemoryProxy的区别,细心的读者可以看到 以上两种方法 使用的proxy使用的不同
MemoryProxy
MemoryProxy只能从JavaScript对象获得数据,可以直接把数组,或JSON和XML格式的数据交给它处理,如下面的代码所示。
var proxy = new Ext.data.MemoryProxy([
['id1','name1','descn1'],
['id2','name2','descn2']
]);
HttpProxy
HttpProxy使用HTTP协议,通过Ajax去后台取数据,构造它时需要设置url:'xxx.jsp'参数。这里的url可以替换成任何一个合法的网址,这样HttpProxy才知道去哪里获取数据,如下面的代码所示。
var proxy = new Ext.data.HttpProxy({url:'xxx.jsp'});
后台需要返回EXT所需要的JSON格式的数据,下面的内容就是后台使用JSP的一个范例,如下面的代码所示。
response.setContentType("application/x-json");
Writer out = response.getWriter();
out.print("[" +
"['id1','name1','descn1']" +
"['id2','name2','descn2']" +
"]");
请注意,这里的HttpProxy不支持跨域,它只能从同一域中获得数据。如果想跨域,请参考下面的ScriptTagProxy。
ScriptTagProxy
ScriptTagProxy的用法几乎和HttpProxy一样,如下面的代码所示。
var proxy = new Ext.data.ScriptTagProxy({url:'xxx.jsp'});
从这里也看不出来它是如何支持跨域的,我们还需要在后台进行相应的处理,如下面的代码所示
String cb = request.getParameter("callback");
response.setContentType("text/javascript");
Writer out = response.getWriter();
out.write(cb + "(");
out.print("[" +
"['id1','name1','descn1']" +
"['id2','name2','descn2']" +
"]");
out.write(");");
其 中的关键就在于从请求中获得的callback参数,这个参数叫做回调函数。ScriptTag- Proxy会在当前的HTML页面里添加一个<script type="text/javascript"src="/xxx.jsp"> </script>标签,然后把后台返回的内容添加到这个标签中,这样就可以解决跨域访问数据的问题。为了让后台返回的内容可以在动态生成的 标签中运行,EXT会生成一个名为callback的回调函数,并把回调函数的名称传递给后台,由后台生成callback(data)形式的响应内容, 然后返回给前台自动运行。