IOException: Unable To Delete Images Due To File Lock

Question

I am Unable To Delete Image File From My Server Path It Gaves Error That The Process Cannot Access The File "FileName" Because it is being Used By Another Process. I Tried Many Methods But Still All In Vain. Please Help me Out in This Issue.

Here is My Code Snippet.

using System;
using System.Data;
using System.Web;
using System.Data.SqlClient;
using System.Web.UI;

using System.Web.UI.HtmlControls;
using System.Globalization;
using System.Web.Security;
using System.Text;
using System.DirectoryServices;
using System.Collections;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

//============ Main Block =================

       byte[] data = (byte[])ds.Tables[0].Rows[0][0];
        MemoryStream ms = new MemoryStream(data);
        Image returnImage = Image.FromStream(ms);

        returnImage.Save(Server.MapPath(".\\TmpImages\\SavedImage.jpg"), System.Drawing.Imaging.ImageFormat.Jpeg);


        returnImage.Dispose();       \\ I Tried this Dispose Method To Unlock The File But Nothing Done.

        ms.Close(); \\ I Tried The Memory Stream Close Method Also But Its Also Not Worked For Me.

       watermark();  \\ Here is My Water Mark Method That Print Water Mark Image on My Saved Image (Image That is Converted From Byte Array)


        DeleteImages();                   \\ Here is My Delete Method That I Call To Delete The Images



//===== ====  My Delete Method To Delete Files==================

            public void DeleteImages()

            {

                 try
                     {

                       File.Delete(Server.MapPath(".\\TmpImages\\WaterMark.jpg"));     \\This Image Deleted Fine.
                       File.Delete(Server.MapPath(".\\TmpImages\\SavedImage.jpg"));   \\ Exception Thrown On Deleting of This Image.
                     }

               catch (Exception ex)
                  {
                    LogManager.LogException(ex, "Error in Deleting Images.");
                    Master.ShowMessage(ex.Message, true);
                 }

             }



\\ ==== Method Declartion That Make Watermark of One Image On Another Image.=======

public void watermark()            
{


    //create a image object containing the photograph to watermark
    Image imgPhoto = Image.FromFile(Server.MapPath(".\\TmpImages\\SavedImage.jpg"));
    int phWidth = imgPhoto.Width;
    int phHeight = imgPhoto.Height;

    //create a Bitmap the Size of the original photograph
    Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

    bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

    //load the Bitmap into a Graphics object
    Graphics grPhoto = Graphics.FromImage(bmPhoto);

    //create a image object containing the watermark
    Image imgWatermark = new Bitmap(Server.MapPath(".\\TmpImages\\PrintasWatermark.jpg"));
    int wmWidth = imgWatermark.Width;
    int wmHeight = imgWatermark.Height;

    //Set the rendering quality for this Graphics object
    grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

    //Draws the photo Image object at original size to the graphics object.
    grPhoto.DrawImage(
        imgPhoto,                               // Photo Image object
        new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
        0,                                      // x-coordinate of the portion of the source image to draw.
        0,                                      // y-coordinate of the portion of the source image to draw.
        phWidth,                                // Width of the portion of the source image to draw.
        phHeight,                               // Height of the portion of the source image to draw.
        GraphicsUnit.Pixel);                    // Units of measure

    //-------------------------------------------------------
    //to maximize the size of the Copyright message we will
    //test multiple Font sizes to determine the largest posible
    //font we can use for the width of the Photograph
    //define an array of point sizes you would like to consider as possiblities
    //-------------------------------------------------------


    //Define the text layout by setting the text alignment to centered
    StringFormat StrFormat = new StringFormat();
    StrFormat.Alignment = StringAlignment.Center;

    //define a Brush which is semi trasparent black (Alpha set to 153)
    SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));



    //define a Brush which is semi trasparent white (Alpha set to 153)
    SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));



    //------------------------------------------------------------
    //Step #2 - Insert Watermark image
    //------------------------------------------------------------

    //Create a Bitmap based on the previously modified photograph Bitmap
    Bitmap bmWatermark = new Bitmap(bmPhoto);
    bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
    //Load this Bitmap into a new Graphic Object
    Graphics grWatermark = Graphics.FromImage(bmWatermark);

    //To achieve a transulcent watermark we will apply (2) color
    //manipulations by defineing a ImageAttributes object and
    //seting (2) of its properties.
    ImageAttributes imageAttributes = new ImageAttributes();

    //The first step in manipulating the watermark image is to replace
    //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
    //to do this we will use a Colormap and use this to define a RemapTable
    ColorMap colorMap = new ColorMap();

    //My watermark was defined with a background of 100% Green this will
    //be the color we search for and replace with transparency
    colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
    colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);

    ColorMap[] remapTable = { colorMap };

    imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);

    //The second color manipulation is used to change the opacity of the
    //watermark.  This is done by applying a 5x5 matrix that contains the
    //coordinates for the RGBA space.  By setting the 3rd row and 3rd column
    //to 0.3f we achive a level of opacity
    float[][] colorMatrixElements = {
                                            new float[] {1.0f,  0.0f,  0.0f,  0.0f, 0.0f},       
                                            new float[] {0.0f,  1.0f,  0.0f,  0.0f, 0.0f},        
                                            new float[] {0.0f,  0.0f,  1.0f,  0.0f, 0.0f},        
                                            new float[] {0.0f,  0.0f,  0.0f,  0.3f, 0.0f},        
                                            new float[] {0.0f,  0.0f,  0.0f,  0.0f, 1.0f}};
    ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);

    imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
        ColorAdjustType.Bitmap);

    //For this example we will place the watermark in the upper right
    //hand corner of the photograph. offset down 10 pixels and to the
    //left 10 pixles

    int xPosOfWm = ((phWidth - wmWidth) - 10);
    int yPosOfWm = 10;

    grWatermark.DrawImage(imgWatermark,
        new Rectangle(xPosOfWm, yPosOfWm, wmWidth, wmHeight),  //Set the detination Position
        0,                  // x-coordinate of the portion of the source image to draw.
        0,                  // y-coordinate of the portion of the source image to draw.
        wmWidth,            // Watermark Width
        wmHeight,            // Watermark Height
        GraphicsUnit.Pixel, // Unit of measurment
        imageAttributes);   //ImageAttributes Object

    //Replace the original photgraphs bitmap with the new Bitmap
    imgPhoto = bmWatermark;
    grPhoto.Dispose();
    grWatermark.Dispose();
    //save new image to file system.
    imgPhoto.Save(Server.MapPath(".\\TmpImages\\WaterMark.jpg"), ImageFormat.Jpeg);

    imgPhoto.Dispose();

   imgWatermark.Dispose();
}

Answer 1

imgPhoto = bmWatermark;

There's your problem, you didn't call imgPhoto.Dispose() first. The file is locked until the finalizer thread runs, that can take a while.

Use the using statement to avoid mistakes like this.

Answer 2

I had the same issue. So I used Process Monitor from SysInternals to see if a another process like my antivirus software was locking it. This was indeed the case for me, although a real-time backup service was also in contention for the file.

To get around this issue I used the following method to try and delete the file multiple times as the other process normally only holds a lock for a very short period of time.

public class FileHelper
{
    public static void Delete(string path)
    {
        int attempts = 0;
        const int maxAttempts = 3;

        do
        {
            try
            {
                attempts++;
                File.Delete(path);

                if (attempts > 1) Trace.TraceInformation("File delete succeeded");

                return;
            }
            catch (IOException)
            {
                Trace.TraceWarning("Could not access file for delete, attempt {0} of {1}", attempts, maxAttempts);

                if (attempts >= maxAttempts) throw;
            }
        }
        while (attempts < maxAttempts);
    }
}

Answer 3

Use Process Monitor by Mark Russinovich and Bryce Cogswell and find out which process has locked the file. Maybe it's your antivirus or something else.

Answer 4

Use "using" constructs. Should the code raise exception, the stream and Image won't be disposed, which can lead to locking the file.

using (MemoryStream ms = new MemoryStream( data ))
using (Image img = Image.FromStream(ms))
{
    //do sth with image
}

Plus if you reopen the image in watermark method, you should dispose it there as well.