为什么Datalist不能显示图片，和删除数据呢？下星期3就要交了，麻烦帮帮忙

Question

能上传图片到文件夹里，但datalist不能显示图片，而且不能实现删除功能，麻烦各位帮帮忙，谢谢

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            DBBind();
        Image1.AlternateText = "图片尚未上传";
        Label1.Visible = false;
        Label2.Visible = false;

    }
    public void DBBind()
    {
        int curpage=Convert.ToInt32(this.Label5.Text);
        PagedDataSource ps=new PagedDataSource();
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        string strSQL = "select * from 图片";
        OleDbDataAdapter da = new OleDbDataAdapter(strSQL, conn);
        DataSet ds = new DataSet();
        da.Fill(ds, "goods");
        ps.DataSource = ds.Tables["goods"].DefaultView;
        ps.AllowPaging = true;
        ps.PageSize = 2;
        ps.CurrentPageIndex = curpage - 1;
        this.LinkButton2.Enabled = true;
        this.LinkButton3.Enabled = true;
        this.LinkButton4.Enabled = true;
        this.LinkButton5.Enabled = true;
        if (curpage == 1)
        {
            this.LinkButton2.Enabled = false;
            this.LinkButton3.Enabled = false;
        }
        if (curpage == ps.PageCount)
        {
            this.LinkButton4.Enabled = false;
            this.LinkButton5.Enabled = false;
        }
        this.Label7.Text = Convert.ToString(ps.PageCount);
        DataList1.DataSource = ps;
        //DataList1.DataKeyField = "goodsid";
        DataList1.DataBind();
        conn.Close();
    }
   
    protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            string name = FileUpload1.PostedFile.FileName;
            FileInfo file = new FileInfo(name);
            string filename = file.Name;
            string webfilepath = Server.MapPath("images/" + filename);
            string filecontenttype = FileUpload1.PostedFile.ContentType;
            if (filecontenttype == "image/bmp" || filecontenttype == "image/gift" || filecontenttype == "image/pjpeg")
            {
                if (!File.Exists(webfilepath))
                {
                    try
                    {
                        FileUpload1.SaveAs(webfilepath);
                        Label1.Visible = true;
                        Label2.Visible = true;
                        Label1.Text = "文件" + filename + "成功上传," + "文件大小为:" + FileUpload1.PostedFile.ContentLength + "字节";
                        Image1.Visible = true;
                        Image1.ImageUrl = "images/" + filename;
                        Image1.Width = 200;
                        Image1.Height = 150;
                        Label2.Text = "按200*150大小显示";
                    }
                    catch (Exception ex)
                    {
                        Label1.Visible = true;
                        Label1.Text = "文件上传失败,失败原因:" + ex.Message;
                    }
                }
                else
                {
                    Label1.Visible = true;
                    Label1.Text = "文件已经存在,请重命名后上传";
                }
            }
            else
            {
                Label1.Visible = true;
                Label1.Text = "文件类型不符,只能上传*.bmp,*.jpg,*.gif类型的文件";
            }
        }
        else
        {
            Label1.Visible = true;
            Label1.Text = "请选择文件或输入文件路径及名称!";
        }
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        string fileExt = System.IO.Path.GetExtension(FileUpload1.PostedFile.FileName).ToLower();
        string newfile = DateTime.Now.ToString("yyMMddhhmmss") + fileExt;
        string webfilepath = Server.MapPath(@"~\Images\" + newfile);
        string strSQL = "insert into 图片(MapNameUrl,MapName,Map_SysData) values('" + webfilepath + "','" + newfile + "','" + DateTime.Now + "')";
        OleDbCommand com = new OleDbCommand(strSQL, conn);
        com.ExecuteNonQuery();
        FileUpload1.SaveAs(webfilepath);
        conn.Close();

    }
    protected void LinkButton2_Click(object sender, EventArgs e)
    {
        this.Label5.Text = "1";
        this.DBBind();
    }

    protected void LinkButton3_Click(object sender, EventArgs e)
    {
        this.Label5.Text = Convert.ToString(Convert.ToInt32(this.Label5.Text) - 1);
        this.DBBind();
    }
    protected void LinkButton4_Click(object sender, EventArgs e)
    {
        this.Label5.Text = Convert.ToString(Convert.ToInt32(this.Label5.Text) + 1);
        this.DBBind();
    }

    protected void LinkButton5_Click(object sender, EventArgs e)
    {
        this.Label5.Text = this.Label7.Text;
        this.DBBind();
    }
    protected void LinkButton1_Click(object sender, EventArgs e)
    {
      
    }
    protected void DataList1_DeleteCommand(object source, DataListCommandEventArgs e)
    {
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        string M_ID = DataList1.DataKeys[e.Item.ItemIndex].ToString();
        string strDel = "delete from 图片 where Map_ID='" + M_ID + "'";
        OleDbCommand delCom = new OleDbCommand(strDel, conn);
        delCom.ExecuteNonQuery();
        conn.Close();
        DataList1.EditItemIndex = -1;
        OleDbConnection con = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        OleDbDataAdapter dr = new OleDbDataAdapter("select*from 图片", con);
        DataSet ds = new DataSet();
        dr.Fill(ds, "UserTab");
        DataList1.DataKeyField = "Map_ID";
        DataList1.DataSource = ds;
        DataList1.DataBind();
       
    }
}

Answer 1

hello.Lz

看到不到你前台HTML无法分析，图片不显示是否路径不对，删除功能不好使，点击删除按钮触发你的事件没，你的删除按钮放在headertemplate，还是itemtemplate，还是FooterTemplate模板里了。

参考：http://msdn.microsoft.com/zh-cn/dd279491.aspx

Answer 2

我的HTML的语言是：<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <table style="width: 766px; height: 387px">
            <tr>
                <td style="width: 100px">
                    <asp:Image ID="Image1" runat="server" />
                    <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></td>
            </tr>
            <tr>
                <td style="width: 100px">
                    <asp:FileUpload ID="FileUpload1" runat="server" />
                    <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="上传" />
                    <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="确定" /></td>
            </tr>
            <tr>
                <td style="width: 100px">
                    <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label></td>
            </tr>
            <tr>
                <td style="width: 100px">
                    <asp:DataList ID="DataList1" runat="server" Height="168px" RepeatColumns="4" RepeatDirection="Horizontal"
                        Width="487px" OnDeleteCommand="DataList1_DeleteCommand">
                        <ItemTemplate>
                            <asp:Image ID="Image2" runat="server" ImageUrl='<%#DataBinder.Eval(Container.DataItem,"MapNameUrl") %>' /><br />
                            <asp:Label ID="Label3" runat="server" Text='<%#  DataBinder.Eval(Container.DataItem,"MapName") %>'></asp:Label><br />
                            <asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click">删除</asp:LinkButton>
                        </ItemTemplate>
                    </asp:DataList></td>
            </tr>
            <tr>
                <td style="width: 100px">
                    <asp:Label ID="Label4" runat="server" Text="当前页面为:"></asp:Label>[<asp:Label ID="Label5"
                        runat="server" Text="1"></asp:Label>]<asp:Label ID="Label6" runat="server" Text="总页码为:"></asp:Label>[<asp:Label
                            ID="Label7" runat="server"></asp:Label>]<asp:LinkButton ID="LinkButton2" runat="server"
                                OnClick="LinkButton2_Click">第一页</asp:LinkButton>
                    <asp:LinkButton ID="LinkButton3" runat="server" OnClick="LinkButton3_Click">上一页</asp:LinkButton>
                    <asp:LinkButton ID="LinkButton4" runat="server" OnClick="LinkButton4_Click">下一页</asp:LinkButton>
                    <asp:LinkButton ID="LinkButton5" runat="server" OnClick="LinkButton5_Click">最后一页</asp:LinkButton></td>
            </tr>
            <tr>
                <td style="width: 100px">
                </td>
            </tr>
        </table>
   
    </div>
    </form>
</body>
</html>

删除按钮放在ITEMTEMPLATE，谢谢你给的参考资料。
我之前已经参考过了。请你帮我分析一下问题的所在。可能是图片的路径出问题，数据库显示的路径是D:\12.19\images\091225125129，但是不知道怎样修改。

Answer 3

此代码只是为了演示,上传和添加数据我都写在按钮里了并做了简化，数据库表我只用了2个字段一个id,一个图片名称,图片不显示是你路径不对，删除不好使请给你的删除按钮CommandName="delete"属性，代码如下

 //增加
    protected void Button2_Click(object sender, EventArgs e)
    {
        OleDbConnection conn = new OleDbConnection(ConfigurationManager.AppSettings["connection"]);
        conn.Open();
        bool Flage=false;
        //取的上传文件扩展名
        string fileExt = System.IO.Path.GetExtension(FileUpload1.PostedFile.FileName).ToLower();
        //定义一个数字允许上传图片的扩展名
        string[] AgreeExPentFile = new string[] { ".jpg", ".jpeg", ".gif", ".bmp"};
        if (FileUpload1.HasFile)
        {
            for (int i = 0; i < AgreeExPentFile.Length; i++)
            {
                if (fileExt.Equals(AgreeExPentFile[i]))
                {
                   Flage = true;
                }
            }
            if (Flage)
            {
                //重新定义上传文件名称 例如：091221013516.jpg
                string newfile = DateTime.Now.ToString("yyMMddhhmmss") + fileExt;
                //讲图片上传到文件夹upload目录下
                string webfilepath = Server.MapPath("upload/" + newfile);
                string strSQL = "Insert Into BL_Table(b_img,b_date) Values('" + newfile + "','" + DateTime.Now + "')";
                OleDbCommand com = new OleDbCommand(strSQL, conn);
                com.ExecuteNonQuery();
                FileUpload1.SaveAs(webfilepath);
                conn.Close();
                DBBind();//调用你的刷新方法
            }
            else
            {
                ScriptManager.RegisterStartupScript(this, GetType(), "jsalert", "alert('图片格式不正确')", true);
                return;
            }
        }       
    }
    //删除
    protected void DataList1_DeleteCommand(object source, DataListCommandEventArgs e)
    {
        OleDbConnection conn = new OleDbConnection(ConfigurationManager.AppSettings["connection"].ToString());
        conn.Open();
        Int32 Id =Convert.ToInt32(DataList1.DataKeys[e.Item.ItemIndex]);
        string strDel = "Delete From BL_Table Where Id=" + Id;
        OleDbCommand com = new OleDbCommand(strDel, conn);
        com.ExecuteNonQuery();
        conn.Close();
        DBBind();//调用你的刷新方法
    }

<asp:DataList ID="DataList1" runat="server" DataKeyField="id" Height="168px" OnDeleteCommand="DataList1_DeleteCommand"
        RepeatColumns="4" RepeatDirection="Horizontal" Width="687px">
        <ItemTemplate>
            <asp:Image ID="Image2" ImageUrl='<%# "upload/"+Eval("b_img") %>' runat="server" Height="100px" Width="100px" />
           <!--或者采用html标签 <img src="upload/<%# Eval("b_img") %>" alt="ToolTip" width="100px" height="100px" /> -->
            <br />
            <asp:LinkButton ID="LinkButton1" runat="server" CommandName="delete">删除</asp:LinkButton>
        </ItemTemplate>
    </asp:DataList>

Answer 4

十分感谢你对我问题的解答，我会努力的

Answer 5

你好，

希望你已经解决了你的问题。
如果显示图片的问题仍然没有解决，请注意你说的数据库中的图片路径为D:\12.19\images\091225125129。

如果你直接把这个绑定到Image控件上当然不行了。你可以获得图片的名字，然后把它转换成web地址，如~/images/091225125129.jpg。

---

Microsoft Online Community Support

Answer 6

问题还是没有解决，希望你能帮帮忙。
这是实现上传图片和将图片相关数据插入到数据库里的代码，我觉得路径需要转换为相对路径，但是不知道如何修改
protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            string name = FileUpload1.PostedFile.FileName;
            FileInfo file = new FileInfo(name);
            string filename = file.Name;
            string webfilepath = Server.MapPath("images/" + filename);
            string filecontenttype = FileUpload1.PostedFile.ContentType;
            if (filecontenttype == "image/bmp" || filecontenttype == "image/gift" || filecontenttype == "image/pjpeg")
            {
                if (!File.Exists(webfilepath))
                {
                    try
                    {
                        FileUpload1.SaveAs(webfilepath);
                        Label1.Visible = true;
                        Label2.Visible = true;
                        Label1.Text = "文件" + filename + "成功上传," + "文件大小为:" + FileUpload1.PostedFile.ContentLength + "字节";
                        Image1.Visible = true;
                        Image1.ImageUrl = "images/" + filename;
                        Image1.Width = 200;
                        Image1.Height = 150;
                        Label2.Text = "按200*150大小显示";
                    }
                    catch (Exception ex)
                    {
                        Label1.Visible = true;
                        Label1.Text = "文件上传失败,失败原因:" + ex.Message;
                    }
                }
                else
                {
                    Label1.Visible = true;
                    Label1.Text = "文件已经存在,请重命名后上传";
                }
            }
            else
            {
                Label1.Visible = true;
                Label1.Text = "文件类型不符,只能上传*.bmp,*.jpg,*.gif类型的文件";
            }
        }
        else
        {
            Label1.Visible = true;
            Label1.Text = "请选择文件或输入文件路径及名称!";
        }
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        //获取上传文件扩展名
        string fileExt = System.IO.Path.GetExtension(FileUpload1.PostedFile.FileName).ToLower();
        //重新定义上传到文件名称
        string newfile = DateTime.Now.ToString("yyMMddhhmmss") + fileExt;
        string webfilepath = Server.MapPath("~images/" + newfile);
        string strSQL = "insert into 图片(MapNameUrl,MapName,Map_SysData) values('" + webfilepath + "','" + newfile + "','" + DateTime.Now + "')";
        OleDbCommand com = new OleDbCommand(strSQL, conn);
        com.ExecuteNonQuery();
        FileUpload1.SaveAs(webfilepath);
        conn.Close();
        DBBind();

    }


这是数据的删除功能，但是实现不了
protected void DataList1_DeleteCommand(object source, DataListCommandEventArgs e)
    {
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;" + "Data Source=" + Server.MapPath("App_Data/eshop.mdb.mdb");
        conn.Open();
        Int32 Id = Convert.ToInt32(DataList1.DataKeys[e.Item.ItemIndex]);
        string strDel = "Delete From 图片 Where Map_ID=" + Id;
        OleDbCommand com = new OleDbCommand(strDel, conn);
        com.ExecuteNonQuery();
        conn.Close();
        DBBind();//调用你的刷新方法

希望你能帮帮手。

Answer 7

你的image文件夹在什么位置？感觉应该是图片引用路径不对。

Answer 8

你好！

针对你的情况我写了个完事的示例，你参照这个例子，修改一下你的代码。

<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    const string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\\DB.mdb;";
    private string fImageDirectory;
    public string ImageDirectory
    {
        get
        {
            if (String.IsNullOrEmpty(fImageDirectory))
                fImageDirectory = Server.MapPath("Images");

            return fImageDirectory;
        }
    }
    private string fImageDirectoryUrl;
    private string ImageDirectoryUrl
    {
        get
        {
            if (String.IsNullOrEmpty(fImageDirectoryUrl))
                fImageDirectoryUrl = String.Format("http://{0}/Images/", Request.Url.Authority);
            
            return fImageDirectoryUrl;
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        /* 表结构
         * 表名: Images
         * ID 文本
         * ImageName 文本
         * ImagePhysicalName 文本
         */
        if (!this.IsPostBack)
            this.BindList();
    }
    
    private void BindList()
    {
        string commandText = "SELECT * FROM [Images]";

        using (OleDbDataAdapter da = new OleDbDataAdapter(commandText, connectionString))
        {
            DataSet ds = new DataSet();
            da.Fill(ds);
            
            this.DataList1.DataSource = ds.Tables[0];
            this.DataList1.DataBind();
        }
    }
    
    protected void btnUpload_Click(object sender, EventArgs e)
    {
        if (this.FileUpload1.HasFile)
        {
            string id = Guid.NewGuid().ToString();
            string imageName = Path.GetFileName(this.FileUpload1.PostedFile.FileName);
            string imagePhysicalName = String.Format("{0}{1}", id, Path.GetExtension(imageName));
            string imagePath = Path.Combine(this.ImageDirectory, imagePhysicalName);

            // 保存物理文件
            this.FileUpload1.SaveAs(imagePath);

            // 添加数据
            using (OleDbConnection conn = new OleDbConnection(connectionString))
            {
                OleDbCommand comm = new OleDbCommand("INSERT INTO [Images] ([ID], [ImageName], [ImagePhysicalName]) VALUES (@ID, @ImageName, @ImagePhysicalName)", conn);
                comm.Parameters.AddWithValue("@Id", id);
                comm.Parameters.AddWithValue("@ImageName", imageName);
                comm.Parameters.AddWithValue("@ImagePhysicalName", imagePhysicalName);
                conn.Open();
                comm.ExecuteNonQuery();
                this.BindList();
            }
            
            this.BindList();
        }
        else
        {
            this.ClientScript.RegisterStartupScript(this.GetType(), "alterMsg", "alert('请选择文件!');", true);
        }
    }

    protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
    {
        if (e.CommandName != "Del") return;
        
        // 删除数据
        using (OleDbConnection conn = new OleDbConnection(connectionString))
        {
            OleDbCommand comm = new OleDbCommand("DELETE FROM [Images] WHERE [Id] = @Id", conn);
            comm.Parameters.AddWithValue("@Id", e.CommandArgument);
            conn.Open();
            comm.ExecuteNonQuery();
        }

        // 删除物理文件
        string imagePhysicalName = ((Label)e.Item.FindControl("Label3")).Text;
        string imagePhysicalPath = Path.Combine(this.ImageDirectory, imagePhysicalName);

        File.Delete(imagePhysicalPath);

        this.BindList();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>上传文件及简单管理示例</title>
</head>
<body>
    <form id="form1" runat="server">
    <asp:FileUpload ID="FileUpload1" runat="server" />
    <asp:Button ID="btnUpload" runat="server" Text="上传" onclick="btnUpload_Click" />
    <asp:DataList ID="DataList1" runat="server" 
        onitemcommand="DataList1_ItemCommand">
        <ItemTemplate>
        <table>
            <tr>
                <td><asp:Label ID="Label1" runat="server" Text='<%# Eval("Id") %>'></asp:Label></td>
                <td><asp:Label ID="Label2" runat="server" Text='<%# Eval("ImageName") %>'></asp:Label></td>
                <td><asp:Label ID="Label3" runat="server" Text='<%# Eval("ImagePhysicalName") %>'></asp:Label></td>
                <td><asp:Image ID="Image1" runat="server" ImageUrl='<%# ImageDirectoryUrl + Eval("ImagePhysicalName") %>' /></td>
                <td><asp:Button ID="btnDelete" CommandName="Del" CommandArgument='<%# Eval("Id") %>' OnClientClick="return confirm('您确定要删除吗？');" runat="server" Text="删除" /></td>
            </tr>
        </table>
        </ItemTemplate>
    </asp:DataList>
    </form>
</body>
</html>

---

知识改变命运，奋斗成就人生!

Answer 9

多谢你的示例，，但可以加一些注析吗，有些我看不懂，而且是第一次接触。谢谢。

Answer 10

不懂的地方可以提出来嘛！

---

知识改变命运，奋斗成就人生!