如何利用noesis.Javascript开源组件.Net中执行javascript脚本

tangjin

作者

本篇内容介绍了“如何利用noesis.Javascript开源组件.Net中执行javascript脚本”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！

界面如下：

然后，click filter button后的UI：

看，筛选出来了，代码如下（js能调C#写的UserInfo类的各个属性）

复制代码代码如下:

public class UserInfo { public string FirstName { get; set; } public string LastName { get; set; } public int Age { get; set; } public override string ToString() { return string.Format("{0}, {1}: {2}", FirstName, LastName, Age); } }

private void btnSearch_Click(object sender, EventArgs e) { List<UserInfo> users = FilterUsers(txtFilter.Text.Trim()); lstUsers.DataSource = users; }

private List<UserInfo> FilterUsers(string jsFilter) { List<UserInfo> results = new List<UserInfo>(); if (jsFilter.Trim().Length == 0) return this.users;

try { using (JavascriptContext context = new JavascriptContext()) { foreach (UserInfo user in this.users) { context.SetParameter("user", user); context.SetParameter("isInclude", false); string js = string.Format(@" if({0}) isInclude=true; else isInclude=false;", jsFilter); context.Run(js); bool isInclude = (bool)context.GetParameter("isInclude"); if (isInclude) results.Add(user); } } } catch { txtFilter.Focus(); txtFilter.SelectAll(); return this.users; }

return results; }

我们来看看效率：

复制代码代码如下:

private void btnTest_Click(object sender, EventArgs e) { using (JavascriptContext context = new JavascriptContext()) { Stopwatch sw = new Stopwatch(); sw.Start(); int i=1000000; while(i-- > 0) { context.SetParameter("ii", 1); context.SetParameter("jj", 2); context.SetParameter("sum", 0); string js = string.Format(@"sum=ii+jj;"); context.Run(js); int sum = (int)context.GetParameter("sum"); } sw.Stop();

long useJS_Total = sw.ElapsedMilliseconds; float useJS_Average = ((float)sw.ElapsedMilliseconds) / 1000000;

sw.Reset(); sw.Start(); i = 1000000; while (i-- > 0) { int ii = 1; int jj = 2; int sum = 0; sum = ii + jj; } sw.Stop();

long nouseJS_Total = sw.ElapsedMilliseconds; float nouseJS_Average = ((float)sw.ElapsedMilliseconds) / 1000000;

string msg = ""; msg += string.Format("useJS_Total: {0}\r\n", useJS_Total); msg += string.Format("useJS_Average: {0}\r\n\r\n\r\n", useJS_Average); msg += string.Format("nouseJS_Total: {0}\r\n", nouseJS_Total); msg += string.Format("nouseJS_Average: {0}\r\n\r\n\r\n", nouseJS_Average);

MessageBox.Show(msg); } }

结果（上面的是通过js引擎计算的时间、下面的是纯C#计算时间，悲剧啊）：这个Noesis.Javascript只适用于性能要求不高的场合