ASP.NET MVC 3 Beta初体验之超酷Chart-技术开发专区

ASP.NET MVC 3 Beta初体验之超酷Chart

作者：朱祁林编辑：胡铭娅 2010-10-21 13:32 来源：朱祁林的博客

　　3、Chart保存

　　将Chart保存到缓存中：看下面代码：

@{
var chartKey = Request["key"];
if (chartKey != null)     {                    var cachedChart = Chart.GetFromCache(key: chartKey);
if (cachedChart == null)
{
cachedChart = new Chart(600, 400);
cachedChart.AddTitle("Cached Chart -- Cached at " + DateTime.Now);
cachedChart.AddSeries(                                name: "Employee",                    axisLabel: "Name",                         xValue: new[]
{  "一月份", "二月份", "三月份", "四月份", "五月份", "六月份", "七月份", "八月份", "九月份"},
yValues: new[] { "2", "6", "4", "5", "3","4","9","2","5"});
cachedChart.SaveToCache(key: chartKey,minutesToCache: 2,slidingExpiration: false);
}
Chart.WriteFromCache(chartKey);
}
}

　　Chart.GetFromCache(key: chartKey)将根据key从缓存中取出Chart，cachedChart.SaveToCache(key: chartKey,minutesToCache: 2,slidingExpiration: false)是将Chart缓存起来。看下图：

　　当再次请求的时候，就直接从缓存中取数据。设置缓存两分钟，两分钟之后这次的缓存失效。

　　将Chart保存为图片：

　　使用下面代码将图形保存为图片：

@{
var filePathName = "_ChartFiles/chart01.jpg";
if (!File.Exists(Server.MapPath(filePathName)))
{
var chartImage = new Chart(600, 400);
chartImage.AddTitle("Chart Title");
chartImage.AddSeries(    name: "Employee",    axisLabel: "Name",    xValue: new[]
{  "一月份", "二月份", "三月份", "四月份", "五月份", "六月份", "七月份", "八月份", "九月份"},    yValues: new[] { "2", "6", "4", "5", "3","4","9","2","5"});    chartImage.Save(path: filePathName);
}
}

　　保存之后的图片：

　　将Chart保存为保存为XML：

@{
Chart chartXml;
var filePathName = "_ChartFiles/XmlChart.xml";
if (File.Exists(Server.MapPath(filePathName)))
{
chartXml = new Chart(width: 600,height: 400,templatePath: filePathName);
}
else
{
chartXml = new Chart(width: 600,height: 400);
chartXml.AddTitle("Chart Title -- Saved at " + DateTime.Now);
chartXml.AddSeries(
name: "Employee",    axisLabel: "Name",    xValue: new[] {  "一月份", "二月份", "三月份", "四月份", "五月份", "六月份", "七月份", "八月份", "九月份"},    yValues: new[] { "2", "6", "4", "5", "3","4","9","2","5"});
   chartXml.SaveXml(path: filePathName);
  }
chartXml.Write();
}

　　从上面代码我们可以看到，可以通过templatePath将XML转换成Chart。通过SaveXml可以将Chart保存为XML。生成的XML如下：

　　总结：本文就三个方面介绍了ASP.NET MVC 3 Beta中的Chart。包括它的数据源配置、显示以及保存。

第1页：配置Chart的数据源第2页：Chart的显示：第3页：Chart保存

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