如何在asp.net中停止在同一页面上复制代码

我真的是新的asp.net，我有页面，我发现我复制的代码，我不想。在普通c#中，我会编写一个函数，从我想要的地方调用它，但在asp.net中，它似乎不允许我这样做。怎么做呢

下面是我复制代码的一个例子

protected void Step02SubmitButton_Click(object sender, EventArgs e)
{
     Session["Step02AllServices"] = Step02AllServices.Checked;
     Session["Step02ContentUploading"] = Step02ContentUploading.Checked;
     Session["Step02ContentLayoutChecking"] = Step02ContentLayoutChecking.Checked;
     Session["Step02TestingVariousBrowsers"] = Step02TestingVariousBrowsers.Checked;
     Session["Step02TestingFunctionality"] = Step02TestingFunctionality.Checked;
     Session["Step02ResponsiveLayouting"] = Step02ResponsiveLayouting.Checked;
     Session["Step02ResponsiveTesting"] = Step02ResponsiveTesting.Checked;
}           
protected void Step02PreviousButton_Click(object sender, EventArgs e)
{
     Session["Step02AllServices"] = Step02AllServices.Checked;
     Session["Step02ContentUploading"] = Step02ContentUploading.Checked;
     Session["Step02ContentLayoutChecking"] = Step02ContentLayoutChecking.Checked;
     Session["Step02TestingVariousBrowsers"] = Step02TestingVariousBrowsers.Checked;
     Session["Step02TestingFunctionality"] = Step02TestingFunctionality.Checked;
     Session["Step02ResponsiveLayouting"] = Step02ResponsiveLayouting.Checked;
     Session["Step02ResponsiveTesting"] = Step02ResponsiveTesting.Checked;
}

protected void Step02SubmitButton_Click(object sender, EventArgs e)
{
     myfunction();
}           
protected void Step02PreviousButton_Click(object sender, EventArgs e)
{
     myfunction();
}
protected void myfunction()
{
    Session["Step02AllServices"] = Step02AllServices.Checked;
     Session["Step02ContentUploading"] = Step02ContentUploading.Checked;
     Session["Step02ContentLayoutChecking"] = Step02ContentLayoutChecking.Checked;
     Session["Step02TestingVariousBrowsers"] = Step02TestingVariousBrowsers.Checked;
     Session["Step02TestingFunctionality"] = Step02TestingFunctionality.Checked;
     Session["Step02ResponsiveLayouting"] = Step02ResponsiveLayouting.Checked;
     Session["Step02ResponsiveTesting"] = Step02ResponsiveTesting.Checked;
}