Google Geochart 可视化库未加载

Question

前段时间，我使用较旧的 Google JS 库版本创建了一个 Google Geochart 小部件。现在谷歌建议升级以更新到加载器 api 而不是 jsapi。无论我如何加载库，对我来说，可视化库都无法正确加载，因此在尝试实例化 GeoChart 对象时我得到一个未定义的结果。其他人也遇到过这个问题吗？

（JS代码是Dojo小部件函数的形式）

update : function(obj, callback){
        
        this._contextObj = obj;
        this._resetSubscriptions(); 
        if (this.apiAccessKey && this.apiAccessKey !== "") {
            google.charts.load('current', {
                'packages':['geochart'],
                // Note: you will need to get a mapsApiKey for your project.
                // See: https://developers.google.com/chart/interactive/docs/basic_load_libs#load-settings
                'mapsApiKey': this.apiAccessKey
                });
                google.charts.setOnLoadCallback(this.drawChart(callback));
        } else {
            var message = " Google Geochart needs an active API key to work!";
            console.error(this._logNode + message);
            alert(message);
        }           

    },  
    drawChart : function (callback) {
        
        // Run this as soon as google charts is loaded.
        // Create map and its container.

        if (!this.geoMap) {

            this.geoMap = new google.visualization.GeoChart(this.geoMapContainer);  
                            
        }
        
        if (this._contextObj){
            this._getObjects(this._contextObj.getGuid,callback);
        } else {
            this._getObjects(null,callback);
        }
        
        this._executeCallback(callback);
                    
    },

Answer 1

setOnLoadCallback 期望引用一个函数 --> this.drawChart

不是函数的结果 --> this.drawChart(callback)

尝试如下...

google.charts.setOnLoadCallback(function () {
  this.drawChart(callback);
});