Question

从GeoExt.data.FeatureStore / Ext.data.Store获取功能（地块）总数时遇到问题，该功能是使用PHP检索的JSON填充的。总数用作显示错误消息（如果未返回任何要素）或包含搜索结果（地图）的窗口的条件。我尝试使用getTotalCount，但无论检索到的JSON是否包含要素，它都会返回0。 Ext JS 3.4.1版。代码：

var store = new GeoExt.data.FeatureStore({
    layer: parcels,
    fields: [{
            name: "name"
        }
    ],
    proxy: new GeoExt.data.ProtocolProxy({
        protocol: new OpenLayers.Protocol.HTTP({
            url: "php/DB2GeoJSON.php",
            format: new OpenLayers.Format.GeoJSON()
        })
    })
});

var formPanel = new GeoExt.form.FormPanel({
    frame: true,
    title: "Search for parcels",
    protocol: new OpenLayers.Protocol.HTTP({
        url: "php/DB2GeoJSON.php",
        format: new OpenLayers.Format.GeoJSON()
    }),
    items: [{
            xtype: "textfield",
            name: "name",
            fieldLabel: "Parcel ID",
            value: ""
        }
    ],
    renderTo: "parcel_search",
    listeners: {
        actioncomplete: function (form, action) {
            json = Ext.util.JSON.decode(action.response.priv._object.responseText);
            features = action.response.features;
            store.loadData(features);
        }
    }
});

formPanel.addButton({
    text: "Search",
    handler: function () {
        this.search();
        var totalCount = store.getTotalCount();
        if (totalCount = "0") {
            Ext.Msg.alert("Alert", "No such parcel ID!");
        } else {
            new Ext.Window({
                title: "Search result"
                height: 400,
                width: 600,
                modal: true,
                layout: "border",
                draggable: false,
                resizable: false,
                closeAction: "hide",
                items: [{
                        region: "center",
                        id: "mappanel",
                        xtype: "gx_mappanel",
                        map: map,
                        split: true
                    }
                ]
            }).show();
        }
    },
    scope: formPanel,
    renderTo: "parcel_search"
})

非常感谢任何帮助...

Answer 1

您的if语句错误：

 if (totalCount = "0") {

应该是：

if (totalCount === 0) {

a=b设置相等的b
a==b检查a是否有点相等b（2=="2" - ＆gt; true）
a==b检查a是否相等b还有a和b的类型（2==="2" - ＆gt; false）

我猜测store.getTotalCount()会返回一个数字。如果不是，你的if语句应该是：

if (totalCount === "0") {

Answer 2

我看到你正在调用我在你的代码中找不到的this.search()。据推测，它是对服务器的异步调用，它立即返回，并且在将数据加载到存储之前。如果我是正确的，你需要在异步调用或商店负载上的事件监听器上设置回调。

Answer 3

通过直接从JSON获取多个功能而不是之后填充的存储并添加json = Ext.util.JSON.decode(action.response.priv._object.responseText);以在按下搜索按钮时执行来管理解决问题。还为表单的初始定义添加了搜索按钮，并将代码的某些部分定义为单独的函数，以便更好地使用。

function mapDisplay() {
    var totalCount = json.totalCount;
    if (totalCount === 0) {
        Ext.Msg.alert("Alert", "No such parcel ID!");
    } else {
        new Ext.Window({
                title: "Search result",
                height: 400,
                width: 600,
                modal: true,
                layout: "border",
                draggable: false,
                resizable: false,
                closeAction: "hide",
                items: [{
                        region: "center",
                        id: "mappanel",
                        xtype: "gx_mappanel",
                        map: map,
                        split: true
                    }
                ]
            }).show();
    }
};

function searchParcel() {
    formPanel.search({
            success: function (form, action) {
                json = Ext.util.JSON.decode(action.response.priv._object.responseText);
                mapDisplay();
            }
        });
};

var formPanel = new GeoExt.form.FormPanel({
        frame: true,
        title: "Search for parcels",
        protocol: new OpenLayers.Protocol.HTTP({
                url: "php/parcel.php",
                format: new OpenLayers.Format.GeoJSON()
            }),
        items: [{
                xtype: "textfield",
                name: "name",
                fieldLabel: "Parcel ID",
                value: ""
            }
        ],
        buttons: [{
                text: "Search",
                handler: searchParcel
            }
        ],
        renderTo: "parcel_search",
        listeners: {
            actioncomplete: function (form, action) {
                features = action.response.features;
                store.loadData(features);
            }
        }
    });

Ext.data.Store getTotalCount总是返回0

3 个答案: