FileUpload.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / WebControls / FileUpload.cs / 1 / FileUpload.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

// 
 

 


namespace System.Web.UI.WebControls {
 
    using System.ComponentModel;
    using System.IO; 
    using System.Security.Permissions; 
    using System.Text;
    using System.Web.UI.HtmlControls; 


    /// 
    /// Displays a text box and browse button that allows the user to select a file for uploading. 
    /// 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    [ControlValueProperty("FileBytes")]
    [ValidationProperty("FileName")] 
    [Designer("System.Web.UI.Design.WebControls.PreviewControlDesigner, " + AssemblyRef.SystemDesign)]
    public class FileUpload : WebControl {

 
        public FileUpload() : base(HtmlTextWriterTag.Input) {
        } 
 
        /// 
        /// Gets the byte contents of the uploaded file.  Needed for ControlParameters and templatized 
        /// ImageFields.
        /// 
        [
        Bindable(true), 
        Browsable(false),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ] 
        public byte[] FileBytes {
            get { 
                Stream fileStream = FileContent;
                if (fileStream != null && fileStream != Stream.Null) {
                    long fileStreamLength = fileStream.Length;
                    BinaryReader reader = new BinaryReader(fileStream); 
                    Byte[] completeImage = null;
 
                    if (fileStreamLength > Int32.MaxValue) { 
                        throw new HttpException(SR.GetString(SR.FileUpload_StreamTooLong));
                    } 

                    if (!fileStream.CanSeek) {
                        throw new HttpException(SR.GetString(SR.FileUpload_StreamNotSeekable));
                    } 

                    int currentStreamPosition = (int)fileStream.Position; 
                    int fileStreamIntLength = (int)fileStreamLength; 
                    try {
                        fileStream.Seek(0, SeekOrigin.Begin); 
                        completeImage = reader.ReadBytes(fileStreamIntLength);
                    }
                    finally {
                        // Don't close or dispose of the BinaryReader because doing so would close the stream. 
                        // We want to put the stream back to the original position in case this getter is called again
                        // and the stream supports seeking, the bytes will be returned again. 
                        fileStream.Seek(currentStreamPosition, SeekOrigin.Begin); 
                    }
                    if (completeImage.Length != fileStreamIntLength) { 
                        throw new HttpException(SR.GetString(SR.FileUpload_StreamLengthNotReached));
                    }
                    return completeImage;
                } 
                return new byte[0];
            } 
        } 

 
        /// 
        /// Gets the contents of the uploaded file.
        /// 
        [ 
        Browsable(false),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ] 
        public Stream FileContent {
            get { 
                HttpPostedFile f = PostedFile;
                if (f != null) {
                    return PostedFile.InputStream;
                } 

                return Stream.Null; 
            } 
        }
 

        /// 
        /// The name of the file on the client's computer, not including the path.
        ///  
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ]
        public string FileName { 
            get {
                HttpPostedFile postedFile = PostedFile;
                string fileName = string.Empty;
 
                if (postedFile != null) {
                    string fullFileName = postedFile.FileName; 
 
                    try {
                        // Some browsers (IE 6, Netscape 4) return the fully-qualified filename, 
                        // like "C:\temp\foo.txt".  The application writer is probably not interested
                        // in the client path, so we just return the filename part.
                        fileName = Path.GetFileName(fullFileName);
                    } 
                    catch {
                        fileName = fullFileName; 
                    } 
                }
 
                return fileName;
            }
        }
 

        ///  
        /// Whether or not a file was uploaded. 
        /// 
        [ 
        Browsable(false),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
        public bool HasFile { 
            get {
                HttpPostedFile f = PostedFile; 
 
                if (f != null) {
                    // Unfortunately returns false if a 0-byte file was uploaded, since we see a 0-byte 
                    // file if the user entered nothing, an invalid filename, or a valid filename
                    // of a 0-byte file.  We feel this scenario is uncommon.
                    return (f.ContentLength > 0);
                } 

                return false; 
            } 
        }
 

        /// 
        /// Provides access to the underlying HttpPostedFile.
        ///  
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ]
        public HttpPostedFile PostedFile { 
            get {
                if (Page != null && Page.IsPostBack) {
                    return Context.Request.Files[UniqueID];
                } 

                return null; 
            } 
        }
 

        protected override void AddAttributesToRender(HtmlTextWriter writer) {
            writer.AddAttribute(HtmlTextWriterAttribute.Type, "file");
            string uniqueID = UniqueID; 
            if (uniqueID != null) {
                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID); 
            } 

            base.AddAttributesToRender(writer); 
        }

        //
 
        protected internal override void OnPreRender(EventArgs e) {
            base.OnPreRender(e); 
            HtmlForm form = Page.Form; 
            if (form != null && form.Enctype.Length == 0) {
                form.Enctype = "multipart/form-data"; 
            }
        }

 
        protected internal override void Render(HtmlTextWriter writer) {
            // Make sure we are in a form tag with runat=server. 
            if (Page != null) { 
                Page.VerifyRenderingInServerForm(this);
            } 

            base.Render(writer);
        }
 

        ///  
        /// Initiates a utility method to save an uploaded file to disk. 
        /// 
        public void SaveAs(string filename) { 
            HttpPostedFile f = PostedFile;
            if (f != null) {
                f.SaveAs(filename);
            } 
        }
 
    } 
}

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