多用户 ASP.NET Web 应用程序中静态变量的范围 [英] Scope of static Variable in multi-user ASP.NET web application
问题描述
静态变量是否在用户会话中保留其值?
Does static variables retain their values across user sessions?
我有一个 ASP.NET Web 应用程序，其中有两个按钮.一个用于设置静态变量值，另一个用于显示静态变量值.
I have a ASP.NET web application where I have two buttons. One for setting the static variable value, another for Showing the static variable value.
namespace WebApplication1
{
public partial class WebForm1 : System.Web.UI.Page
{
public static int customerID;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void ButtonSetCustomerID_Click(object sender, EventArgs e)
{
customerID = Convert.ToInt32(TextBox1.Text);
}
protected void ButtonGetCustomerID_Click(object sender, EventArgs e)
{
Label1.Text = Convert.ToString(customerID);
}
}
}
虽然这在单用户环境中有效，但如果有 2 个用户同时从两台计算机登录会发生什么情况，用户 1 将值设置为 100，然后用户 2 将值设置为 200.之后用户 1 调用 Get值按钮.他会看到什么价值?
While this works in single-user environment, What happens if there are 2 users simultaneously logged in from two computers, User 1 sets the value as 100, then User 2 sets the value as 200. after that user 1 invokes the Get Value button. What will he see as the value?
推荐答案
静态变量是否在用户会话中保留其值?
Does static variables retain their values across user sessions?
是的，这就是为什么在 Web 应用程序中使用静态变量时应该非常小心的原因.您将遇到并发问题，因为为一个请求服务的多个线程可以修改变量的值.
Yes, that's why you should be VERY careful when you use static variables in a web app. You will run in concurrency issues as more than one thread servicing a request can modify the value of the variable.
虽然这在单用户环境中有效，但如果有2 个用户同时从两台计算机登录，用户 1 设置值为 100，然后用户 2 将值设置为 200.在用户 1 之后调用获取值按钮.他会看到什么价值?
While this works in single-user environment, What happens if there are 2 users simultaneously logged in from two computers, User 1 sets the value as 100, then User 2 sets the value as 200. after that user 1 invokes the Get Value button. What will he see as the value?
用户会在之后看到 200.
The user will see 200 afterwards.
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