如何从 C# 中的不同方法访问变量？

Question

如何访问 page_load 上的变量并在 c# 中的 ddlApp_SelectedIndexChanged 方法上使用它？ 谢谢

private void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        ddlRole.SelectedIndex = 0;
    }

    string ddl = ddlApp.Value.ToString();
    string ddlRoleDs;
    string ddlMenuDs;
    string GvDs;

    if (ddl == "ATTD")
    {
        ddlRoleDs = "ddlAttdDs";
        ddlMenuDs = "ddlMenuAttdDs";
        GvDs = "AttdMenuAssignmentDs";                
    }
    else if (ddl == "TRVL")
    {
        ddlRoleDs = "ddlTrvldDs";
        ddlMenuDs = "ddlMenuTrvlDs";
        GvDs = "TrvlMenuAssignmentDs";                
    }

}

变量：ddlRoleDs、GvDs 和 ddMenuDs

protected void ddlApp_SelectedIndexChanged(object sender, EventArgs e)
{        
    ddlRole.DataSourceID = ddlRoleDs;
    MenuAssignmentGv.DataSourceID = GvDs;
    ddlMenu.DataSourceID = ddlMenuDs;
}

Answer 1

您可以在班级中使用私有全局成员。这样，它们只能从类中访问。下面的代码向您展示了如何声明和使用它们

private string ddlRoleDs;
private string GvDs;
private string ddMenuDs;

private void Page_Load(object sender, EventArgs e)
{
    // don't declare them here, but you can use them here
    ddlRoleDs = "test value";
    ....
}

在Page_load方法中设置好值后，就可以在你的其他方法中使用了

protected void ddlApp_SelectedIndexChanged(object sender, EventArgs e)
{        
    ddlRole.DataSourceID = ddlRoleDs;
    MenuAssignmentGv.DataSourceID = GvDs;
    ddlMenu.DataSourceID = ddlMenuDs;
}