why my extjs combobox is not filled dynamically?

Here is my Extjs onReady function

var sto开发者_开发问答re = new Ext.data.Store({
                                  proxy: new Ext.data.HttpProxy({
                                  url: '/loginjson.json'
                                  }),

                                  reader: new Ext.data.JsonReader(
                                  {root: 'row', fields:['dblist']}
                                    )
                    });
            store.load();

and here I'm using it in my FormPanel like

renderTo: document.getElementById("loginform"),
                                    title: "Login Form",
                                    items: [{
                                        xtype: 'combo',
                                        fieldLabel: 'genre',
                                        name: 'genre',
                                        store: store,
                                        autoLoad: true,
                                        displayField: 'dblist',
                                    }

and JSON URL of django returns like this

http://localhost:8000/loginjson.json

{"row": [{"dblist": "datalist"}]}

but my combobox is not filled I'm missing somewhere on extJS but couldn't found.

If you are expecting the ComboBox to behave more like an HTML select field then add to your ComboBox config the property:

triggerAction: 'all'

This will ensure that all items in the store will be displayed when the field's trigger button is clicked.

The ComboBox config will also be needing a valueField property:

valueField: 'dblist'

Also, explicitly calling the store's load method is not necessary. The ComboBox will handle that for you at the appropriate time.

I think the fields property of your JSON reader is not configured correctly. Try this:

reader: new Ext.data.JsonReader({
            root: 'row'
        ,   fields:[{name: "dblist"}]
        })