为什么我必须调用 new Chart() 来触发来自同一个类的方法(比如)?这是正确的方法吗?谢谢。
function Chart(location, startDateString, endDateString) {
this.location = location;
this.startDateString = startDateString;
this.endDateString = endDateString;
}
Chart.prototype.fnDrawStaticChart = function(chartUrl, chartData) {
$.get(chartUrl, function() {
$('#'+chartData.wrapSpecId).attr('src', chartUrl);
});
}
Chart.prototype.fnDraw = function(fnStaticChartJSON, fnStaticChartImage) {
$.getJSON(fnStaticChartJSON, function(data) {
if (data.chartData.length > 0) {
$('#chartDiv').append($('#template').jqote(data, '@'));
$.each(data.chartData, function(index, chartData) {
var pkgLineId = chartData.wrapSpec2.pkgLineId.pkgLineId;
var wrapSpecId = chartData.wrapSpecId;
var startDate = data.startDate;
var endDate = data.endDate;
var chartUrl = fnStaticChartImage({
pkg_line_id: pkgLineId,
wrap_spec_id: wrapSpecId,
start_date: startDate,
end_date: endDate
});
this.fnDrawStaticChart(chartUrl, chartData); //can't do this.
new Chart().fnDrawStaticChart(chartUrl, chartData); CAN do this.
});
});
}
最佳答案
这是一个简单的范围界定问题。 this 指向您传递给 $.each 的函数。您必须将旧的 this 引用存储在另一个变量中:
Chart.prototype.fnDraw = function(fnStaticChartJSON, fnStaticChartImage) {
var self = this;
$.getJSON(fnStaticChartJSON, function(data) {
if (data.chartData.length > 0) {
$('#chartDiv').append($('#template').jqote(data, '@'));
$.each(data.chartData, function(index, chartData) {
var pkgLineId = chartData.wrapSpec2.pkgLineId.pkgLineId;
var wrapSpecId = chartData.wrapSpecId;
var startDate = data.startDate;
var endDate = data.endDate;
var chartUrl = fnStaticChartImage({
pkg_line_id: pkgLineId,
wrap_spec_id: wrapSpecId,
start_date: startDate,
end_date: endDate
});
self.fnDrawStaticChart(chartUrl, chartData);
new Chart().fnDrawStaticChart(chartUrl, chartData);
});
});
}
关于Javascript:对象在使用原型(prototype)时没有方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6685997/