如何從C＃中的不同方法訪問變量？

Question

如何訪問page_load上的變量並在c＃中使用ddlApp_SelectedIndexChanged方法？ 謝謝

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";     
    } 

} 

變量：ddlRoleDs，GvDs和ddMenuDs

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

Answer 1

您可以在類中使用私有的全球成員。這樣他們只能在課堂上進行訪問。下面的代碼顯示你到底如何聲明和使用它們

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"; 
    .... 
} 

的值在Page_Load方法設置後，就可以在你的另一種方法可以使用

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