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社区首页 >问答首页 >If / else语句ASP.NET C#

If / else语句ASP.NET C#
EN

Stack Overflow用户
提问于 2012-01-27 04:44:11
回答 3查看 2.9K关注 0票数 2

到目前为止,我正在尝试创建一个ASP.NET页面,它将列出一个类别中的图书,在一个列表框中,根据你选择的类别按钮,然后我有另外两个按钮(一个用于下单和一个下单)。现在的问题是,当我点击虚构按钮并填充列表框后单击ASC或DESC按钮时,它会擦除列表框,并将我抛回pageload事件。

我曾尝试将填充项目移动到页面加载事件,当我完成所有操作时,一切都很完美,但由于某些原因,当通过其他按钮单击来执行此操作时,它就不起作用了。

我是ASP.NET的新手,所以非常欢迎简单的或者“新的友好”的解释和代码示例/修复!

提前感谢!

下面的代码

代码语言:javascript
运行
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class partin : System.Web.UI.Page
{
private List<String> books = new List<String>();

public void Page_PreRender()
{
    Item_Listbox.DataSource = books;
    Item_Listbox.DataBind();
}

int SortASC(string x, string y)
{
    return String.Compare(x, y);
}

int SortDESC(string x, string y)
{
    return String.Compare(x, y) * -1;
}

protected void Page_Load(object sender, EventArgs e)
{
    Header_Label.Text = "Welcome! Please select a book category.";


}



protected void Fiction_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Fiction Section";

    books.Add("Title: The Old Man and The Sea | Decription: An epic novel. | Price: 10 USD | Quantity: 3");
    books.Add("Title: A Game of Thrones | Decription: A tale of fire and ice. | Price: 15 USD | Quantity: 6");
    books.Add("Title: Dracula | Decription: A book about vampires. | Price: 5 USD | Quantity: 7");
    books.Add("Title: Twilight | Decription: An awful book. | Price: Free | Quantity: 1000");  

}


protected void Non_Fiction_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Non-Fiction Section";



}
protected void Self_Help_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Self Help Section";



}

protected void Sort_Command(object sender, CommandEventArgs e)
{
    if (e.CommandName == "Sort")
    {
        switch (e.CommandArgument.ToString())
        {
            case "ASC":
                books.Sort(SortASC);
                break;
            case "DESC":
                books.Sort(SortDESC);
                break;
        }
    }
}



}

编辑:感谢你的帖子,它不再直接返回到页面加载事件,并将标签中的更改保留为“虚构”,但当我单击ASD或DESC按钮时,它仍会重置ListBox中的数据。

EN

Stack Overflow用户

发布于 2012-01-27 04:54:18

检查页面加载和排序命令修改事件

代码语言:javascript
运行
复制
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class partin : System.Web.UI.Page
{
private List<String> books = new List<String>();

public void Page_PreRender()
{
    Item_Listbox.DataSource = books;
    Item_Listbox.DataBind();
}

int SortASC(string x, string y)
{
    return String.Compare(x, y);
}

int SortDESC(string x, string y)
{
    return String.Compare(x, y) * -1;
}

protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack){

    Header_Label.Text = "Welcome! Please select a book category.";
    Item_Listbox.DataSource = books;
    Item_Listbox.DataBind();

}

}



protected void Fiction_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Fiction Section";

    books.Add("Title: The Old Man and The Sea | Decription: An epic novel. | Price: 10 USD | Quantity: 3");
    books.Add("Title: A Game of Thrones | Decription: A tale of fire and ice. | Price: 15 USD | Quantity: 6");
    books.Add("Title: Dracula | Decription: A book about vampires. | Price: 5 USD | Quantity: 7");
    books.Add("Title: Twilight | Decription: An awful book. | Price: Free | Quantity: 1000");  

}


protected void Non_Fiction_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Non-Fiction Section";



}
protected void Self_Help_Click(object sender, EventArgs e)
{
    Header_Label.Text = "Self Help Section";



}

protected void Sort_Command(object sender, CommandEventArgs e)
{
    if (e.CommandName == "Sort")
    {
        switch (e.CommandArgument.ToString())
        {
            case "ASC":
                books.Sort(SortASC);
                break;
            case "DESC":
                books.Sort(SortDESC);
                break;
        }
    }
    Item_Listbox.DataSource = books;  
    Item_Listbox.DataBind();  
}

}
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/9025055

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