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使用ASP.NET上传图片汇总

2013-07-08 21:12 344 查看
转自chang_xing的博客：http://blog.csdn.net/chang_xing/article/details/9139193

1、使用标准HTML来进行图片上传

前台代码：

<body> 
    <form id="form1" runat="server"> 
    <div> 
        <table> 
            <tr> 
                <td colspan="2" style="height: 21px" > 
                    使用标准HTML来进行图片上传</td> 
            </tr> 
            <tr> 
                <td style="width: 400px"> 
                    <input id="InputFile" style="width: 399px" type="file" runat="server" /></td> 
                <td style="width: 80px"> 
                    <asp:Button ID="UploadButton" runat="server" Text="上传图片" OnClick="UploadButton_Click" /></td> 
            </tr> 
            <tr> 
                <td colspan="2" > 
                    <asp:Label ID="Lb_Info" runat="server" ForeColor="Red"></asp:Label></td>                 
            </tr> 
        </table>     
    </div> 
    </form> 
</body>


后台代码：

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 

public partial class _Default : System.Web.UI.Page  
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 
    protected void UploadButton_Click(object sender, EventArgs e) 
    { 
        string uploadName = InputFile.Value;//获取待上传图片的完整路径，包括文件名 
        //string uploadName = InputFile.PostedFile.FileName; 
        string pictureName = "";//上传后的图片名，以当前时间为文件名，确保文件名没有重复 
        if (InputFile.Value != "") 
        { 
            int idx = uploadName.LastIndexOf("."); 
            string suffix = uploadName.Substring(idx);//获得上传的图片的后缀名 
            pictureName = DateTime.Now.Ticks.ToString() + suffix; 
        } 
        try 
        { 
            if (uploadName != "") 
            { 
                string path = Server.MapPath("~/images/"); 
                InputFile.PostedFile.SaveAs(path + pictureName); 
            } 
        } 
        catch (Exception ex) 
        { 
            Response.Write(ex); 
        } 
    } 
}


2、单文件上传

这是最基本的文件上传，在APSP.NET1.x中没有这个FileUpload控件，只有html的上传控件，那时候要把html控件转化为服务器控件，很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生，第一个例子虽然简单却是根本。

前台代码：

<body> 
    <form id="form1" runat="server"> 
    <div> 
        <table style="width: 90%"> 
            <tr> 
                <td style="width: 159px" colspan=2> 
                    <strong><span style="font-size: 10pt">最简单的单文件上传</span></strong></td> 
            </tr> 
            <tr> 
                <td style="width: 600px"> 
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="600px" /></td> 
                <td align=left> 
                    <asp:Button ID="FileUpload_Button" runat="server" Text="上传图片" OnClick="FileUpload_Button_Click" /></td> 
            </tr> 
            <tr> 
                <td colspan=2> 
                    <asp:Label ID="Upload_info" runat="server" ForeColor="Red" Width="767px"></asp:Label></td> 
            </tr> 
        </table>     
    </div> 
    </form> 
</body>


后台代码：

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 

public partial class _Default : System.Web.UI.Page  
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 
    protected void FileUpload_Button_Click(object sender, EventArgs e) 
    { 
        try 
        { 
            if (FileUpload1.PostedFile.FileName == "") 
            //if (FileUpload1.FileName == "") 
            //if (!FileUpload1.HasFile)     //获取一个值，该值指示 System.Web.UI.WebControls.FileUpload 控件是否包含文件。包含文件，则为 true；否则为 false。 
            { 
                this.Upload_info.Text = "请选择上传文件！"; 
            } 
            else 
            { 
                string filepath = FileUpload1.PostedFile.FileName;  //得到的是文件的完整路径,包括文件名，如：C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg 
                //string filepath = FileUpload1.FileName;               //得到上传的文件名20022775_m.jpg 
                string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg 
                string serverpath = Server.MapPath("~/images/") + filename;//取得文件在服务器上保存的位置C:\Inetpub\wwwroot\WebSite1\images\20022775_m.jpg 
                FileUpload1.PostedFile.SaveAs(serverpath);//将上传的文件另存为 
                this.Upload_info.Text = "上传成功！"; 
            } 
        } 
        catch (Exception ex) 
        { 
            this.Upload_info.Text = "上传发生错误！原因是：" + ex.ToString(); 
        } 
    } 
}


3、多文件上传

前台代码：

<body> 
    <form id="form1" runat="server"> 
    <div> 
    <table style="width: 343px"> 
            <tr> 
                <td style="width: 100px"> 
                    多文件上传</td> 
                <td style="width: 100px"> 
                </td> 
            </tr> 
            <tr> 
                <td style="width: 100px"> 
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="475px" /> 
                    </td> 
                <td style="width: 100px"> 
                    </td> 
            </tr> 
            <tr> 
                <td style="width: 100px"> 
                    <asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td> 
                <td style="width: 100px"> 
                </td> 
            </tr> 
            <tr> 
                <td style="width: 100px"> 
                    <asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td> 
                <td style="width: 100px"> 
                </td> 
            </tr> 
            <tr> 
                <td style="width: 100px"> 
                    <asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上传" /> 
                    <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="448px"></asp:Label></td> 
                <td style="width: 100px"> 
                </td> 
            </tr> 
        </table> 
    </div> 
    </form> 
</body>


后台代码：

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 

public partial class _Default : System.Web.UI.Page  
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 
    protected void bt_upload_Click(object sender, EventArgs e) 
    { 
        if (FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "" && FileUpload3.PostedFile.FileName == "") 
        { 
            this.lb_info.Text = "请选择文件！"; 
        } 
        else 
        { 
            HttpFileCollection myfiles = Request.Files; 
            for (int i = 0; i < myfiles.Count; i++) 
            { 
                HttpPostedFile mypost = myfiles[i]; 
                try 
                { 
                    if (mypost.ContentLength > 0) 
                    { 
                        string filepath = mypost.FileName;//C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg 
                        string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg 
                        string serverpath = Server.MapPath("~/images/") + filename;//C:\Inetpub\wwwroot\WebSite2\images\20022775_m.jpg 
                        mypost.SaveAs(serverpath); 
                        this.lb_info.Text = "上传成功！"; 
                    } 
                } 
                catch (Exception ex) 
                { 
                    this.lb_info.Text = "上传发生错误！原因：" + ex.Message.ToString(); 
                } 
            } 
        } 
    } 
}


4、客户端检查上传文件类型(以上传图片为例)

客户端代码：

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %> 

<!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>客户端检查上传文件类型</title> 
    <script language="javascript"> 
    function Check_FileType() 
    { 
        var str=document.getElementById("FileUpload1").value; 
        var pos=str.lastIndexOf("."); 
        var lastname=str.substring(pos,str.length); 
        if(lastname.toLowerCase()!=".jpg"&&lastname.toLowerCase()!=".gif") 
        { 
            alert("您上传的文件类型为"+lastname+"，图片必须为.jpg,.gif类型"); 
            return false; 
        } 
        else 
        { 
            return true; 
        }         
    } 
    </script> 
</head> 
<body> 
    <form id="form1" runat="server"> 
    <div> 
        <table> 
            <tr> 
                <td colspan="2"> 
                    客户端检查上传文件类型</td>                 
            </tr> 
            <tr> 
                <td style="width: 444px"> 
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td> 
                <td style="width: 80px"> 
                    <asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" OnClientClick="return Check_FileType()" /></td> 
            </tr> 
            <tr> 
                <td colspan="2" style="height: 21px"> 
                    <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>                 
            </tr> 
        </table>     
    </div> 
    </form> 
</body> 
</html>
注意：点击上传时先触发客户端事件OnClientClick="return Check_FileType()"

后台代码：

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 

public partial class _Default : System.Web.UI.Page  
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 

    protected void bt_upload_Click(object sender, EventArgs e) 
    { 
        try 
        { 
            if (FileUpload1.PostedFile.FileName == "") 
            { 
                this.lb_info.Text = "请选择文件！"; 
            } 
            else 
            { 
                string filepath = FileUpload1.PostedFile.FileName; 
                //if (!IsAllowedExtension(FileUpload1)) 
                //{ 
                //    this.lb_info.Text = "上传文件格式不正确！"; 
                //} 
                if (IsAllowedExtension(FileUpload1) == true) 
                { 
                    string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1); 
                    string serverpath = Server.MapPath("~/images/") + filename; 
                    FileUpload1.PostedFile.SaveAs(serverpath); 
                    this.lb_info.Text = "上传成功！"; 
                } 
                else 
                { 
                    this.lb_info.Text = "请上传图片！"; 
                } 
            } 
        } 
        catch (Exception ex) 
        { 
            this.lb_info.Text = "上传发生错误！原因：" + ex.ToString(); 
        } 
    } 
    private static bool IsAllowedExtension(FileUpload upfile) 
    { 
        string strOldFilePath = ""; 
        string strExtension=""; 
        string[] arrExtension ={ ".gif", ".jpg", ".bmp", ".png" }; 
        if (upfile.PostedFile.FileName != string.Empty) 
        { 
            strOldFilePath = upfile.PostedFile.FileName;//获得文件的完整路径名 
            strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));//获得文件的扩展名，如：.jpg 
            for (int i = 0; i < arrExtension.Length; i++) 
            { 
                if (strExtension.Equals(arrExtension[i])) 
                { 
                    return true; 
                } 
            } 
        } 
        return false; 
    } 
}


注意：若去掉客户端的脚本和客户端事件OnClientClick="return Check_FileType()"，在后台代码

改为：

if (!IsAllowedExtension(FileUpload1)) 
                { 
                    this.lb_info.Text = "上传文件格式不正确！"; 
                } 
else if (IsAllowedExtension(FileUpload1) == true)
即变成服务器端检查上传文件类型。

5、服务器端检查上传文件的类型(文件内部真正的格式)

客户端代码：

<body> 
    <form id="form1" runat="server"> 
    <div> 
        <table> 
            <tr> 
                <td colspan="2"> 
                    服务器检查上传文件类型</td>                 
            </tr> 
            <tr> 
                <td style="width: 444px"> 
                    <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td> 
                <td style="width: 80px"> 
                    <asp:Button ID="bt_upload" runat="server" Text="上传图片" OnClick="bt_upload_Click" /></td> 
            </tr> 
            <tr> 
                <td colspan="2" style="height: 21px"> 
                    <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>                 
            </tr> 
        </table>     
    </div> 
    </form> 
</body>


后台代码：

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.IO; 

public partial class _Default : System.Web.UI.Page  
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 
    protected void bt_upload_Click(object sender, EventArgs e) 
    { 
        try 
        { 
            if (FileUpload1.PostedFile.FileName == "") 
            { 
                this.lb_info.Text = "请选择文件！"; 
            } 
            else 
            { 
                string filepath = FileUpload1.PostedFile.FileName; 
                if (IsAllowedExtension(FileUpload1) == true) 
                { 
                    string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1); 
                    string serverpath = Server.MapPath("images/") + filename; 
                    FileUpload1.PostedFile.SaveAs(serverpath); 
                    this.lb_info.Text = "上传成功！"; 
                } 
                else 
                { 
                    this.lb_info.Text = "请上传图片"; 
                } 
            } 
        } 
        catch (Exception error) 
        { 
            this.lb_info.Text = "上传发生错误！原因：" + error.ToString(); 
        } 
    } 
    private static bool IsAllowedExtension(FileUpload upfile) 
    { 
        FileStream fs = new FileStream(upfile.PostedFile.FileName, FileMode.Open, FileAccess.Read); 
        BinaryReader r = new BinaryReader(fs); 
        string fileclass = ""; 
        byte buffer; 
        try 
        { 
            buffer = r.ReadByte(); 
            fileclass = buffer.ToString(); 
            buffer = r.ReadByte(); 
            fileclass += buffer.ToString(); 
        } 
        catch 
        {  
             
        } 
        r.Close(); 
        fs.Close(); 
        if (fileclass == "255216" || fileclass == "7173"||fileclass=="6677"||fileclass=="13780")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar 
        { 
            return true; 
        } 
        else 
        { 
            return false; 
        } 
    } 
}
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