In this blog, I will show how to upload files to a folder using C# code. This will help you to understand the file upload feature in C#.
First, we have to create a WinForm like in the given image.
Here is the code for FileUpload.Designer.cs file.
  1. namespace FileUploads
  2. {
  3. partial class FileUpload
  4. {
  5. /// <summary>
  6. /// Required designer variable.
  7. /// </summary>
  8. private System.ComponentModel.IContainer components = null;
  10. /// <summary>
  11. /// Clean up any resources being used.
  12. /// </summary>
  13. /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
  14. protected override void Dispose(bool disposing)
  15. {
  16. if (disposing && (components != null))
  17. {
  18. components.Dispose();
  19. }
  20. base.Dispose(disposing);
  21. }
  23. #region Windows Form Designer generated code
  25. /// <summary>
  26. /// Required method for Designer support - do not modify
  27. /// the contents of this method with the code editor.
  28. /// </summary>
  29. private void InitializeComponent()
  30. {
  31. this.btnFile = new System.Windows.Forms.Button();
  32. this.dgvFile = new System.Windows.Forms.DataGridView();
  33. this.fileName = new System.Windows.Forms.DataGridViewTextBoxColumn();
  34. this.filePath = new System.Windows.Forms.DataGridViewTextBoxColumn();
  35. this.fileSavePath = new System.Windows.Forms.DataGridViewTextBoxColumn();
  36. this.btnSave = new System.Windows.Forms.Button();
  37. this.btnClear = new System.Windows.Forms.Button();
  38. ((System.ComponentModel.ISupportInitialize)(this.dgvFile)).BeginInit();
  39. this.SuspendLayout();
  40. //
  41. // btnFile
  42. //
  43. this.btnFile.Font = new System.Drawing.Font("Segoe UI", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
  44. this.btnFile.Location = new System.Drawing.Point(289, 3);
  45. this.btnFile.Name = "btnFile";
  46. this.btnFile.Size = new System.Drawing.Size(97, 31);
  47. this.btnFile.TabIndex = 10;
  48. this.btnFile.Text = "....Choose File";
  49. this.btnFile.UseVisualStyleBackColor = true;
  50. this.btnFile.Click += new System.EventHandler(this.btnFile_Click);
  51. //
  52. // dgvFile
  53. //
  54. this.dgvFile.AllowUserToAddRows = false;
  55. this.dgvFile.AllowUserToDeleteRows = false;
  56. this.dgvFile.BackgroundColor = System.Drawing.SystemColors.Control;
  57. this.dgvFile.ColumnHeadersHeight = 28;
  58. this.dgvFile.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.DisableResizing;
  59. this.dgvFile.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
  60. this.fileName,
  61. this.filePath,
  62. this.fileSavePath});
  63. this.dgvFile.Location = new System.Drawing.Point(2, 39);
  64. this.dgvFile.Name = "dgvFile";
  65. this.dgvFile.ReadOnly = true;
  66. this.dgvFile.RowHeadersVisible = false;
  67. this.dgvFile.RowHeadersWidth = 30;
  68. this.dgvFile.Size = new System.Drawing.Size(693, 258);
  69. this.dgvFile.TabIndex = 1;
  70. //
  71. // fileName
  72. //
  73. this.fileName.DataPropertyName = "cname";
  74. this.fileName.HeaderText = "Name";
  75. this.fileName.Name = "fileName";
  76. this.fileName.ReadOnly = true;
  77. this.fileName.Width = 150;
  78. //
  79. // filePath
  80. //
  81. this.filePath.DataPropertyName = "cpath";
  82. this.filePath.HeaderText = "Path";
  83. this.filePath.Name = "filePath";
  84. this.filePath.ReadOnly = true;
  85. this.filePath.Width = 250;
  86. //
  87. // fileSavePath
  88. //
  89. this.fileSavePath.DataPropertyName = "csaveto";
  90. this.fileSavePath.HeaderText = "Save To";
  91. this.fileSavePath.Name = "fileSavePath";
  92. this.fileSavePath.ReadOnly = true;
  93. this.fileSavePath.Width = 300;
  94. //
  95. // btnSave
  96. //
  97. this.btnSave.Font = new System.Drawing.Font("Segoe UI Semibold", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
  98. this.btnSave.Location = new System.Drawing.Point(351, 304);
  99. this.btnSave.Name = "btnSave";
  100. this.btnSave.Size = new System.Drawing.Size(98, 32);
  101. this.btnSave.TabIndex = 9;
  102. this.btnSave.Text = "Save";
  103. this.btnSave.UseVisualStyleBackColor = true;
  104. this.btnSave.Click += new System.EventHandler(this.btnSave_Click);
  105. //
  106. // btnClear
  107. //
  108. this.btnClear.Font = new System.Drawing.Font("Segoe UI Semibold", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
  109. this.btnClear.Location = new System.Drawing.Point(247, 304);
  110. this.btnClear.Name = "btnClear";
  111. this.btnClear.Size = new System.Drawing.Size(98, 32);
  112. this.btnClear.TabIndex = 10;
  113. this.btnClear.Text = "Clear";
  114. this.btnClear.UseVisualStyleBackColor = true;
  115. this.btnClear.Click += new System.EventHandler(this.btnClear_Click);
  116. //
  117. // FileUpload
  118. //
  119. this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 17F);
  120. this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
  121. this.BackColor = System.Drawing.SystemColors.Control;
  122. this.ClientSize = new System.Drawing.Size(697, 345);
  123. this.Controls.Add(this.btnFile);
  124. this.Controls.Add(this.btnClear);
  125. this.Controls.Add(this.btnSave);
  126. this.Controls.Add(this.dgvFile);
  127. this.Font = new System.Drawing.Font("Segoe UI", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
  128. this.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
  129. this.MaximizeBox = false;
  130. this.Name = "FileUpload";
  131. this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
  132. this.Text = "File Upload";
  133. this.Load += new System.EventHandler(this.FileUpload_Load);
  134. ((System.ComponentModel.ISupportInitialize)(this.dgvFile)).EndInit();
  135. this.ResumeLayout(false);
  137. }
  139. #endregion
  140. private System.Windows.Forms.DataGridView dgvFile;
  141. private System.Windows.Forms.Button btnSave;
  142. private System.Windows.Forms.Button btnFile;
  143. private System.Windows.Forms.Button btnClear;
  144. private System.Windows.Forms.DataGridViewTextBoxColumn fileName;
  145. private System.Windows.Forms.DataGridViewTextBoxColumn filePath;
  146. private System.Windows.Forms.DataGridViewTextBoxColumn fileSavePath;
  147. }
  148. }
Then, we have to declare two variables. One is to where you want to save the file and another one is a data table where we store the uploaded file details.
  1. string strSavePath = @"D:\MyFolder\";
  2. DataTable dtData;
Now, on the page load event, initialize that data table by calling the "CreateTable" method.
  1. private void FileUpload_Load(object sender, EventArgs e)
  2. {
  3. dtData = CreateTable();
  4. }
  6. private DataTable CreateTable()
  7. {
  8. DataTable dtReturn = new DataTable();
  9. dtReturn.Columns.Add("cname", typeof(string));
  10. dtReturn.Columns.Add("cpath", typeof(string));
  11. dtReturn.Columns.Add("csaveto", typeof(string));
  12. return dtReturn;
  13. }
Here, we choose one file or multiple files to save to MyFolder.
  1. OpenFileDialog fdlg = new OpenFileDialog();
  2. fdlg.Title = "Select file";
  3. fdlg.InitialDirectory = Environment.SpecialFolder.Desktop.ToString();
  4. fdlg.Filter = string.Format("{0}{1}{2} ({3})|{3}", fdlg.Filter, "", "All Files", "*.*");
  5. // Code for image filter
  6. ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
  7. foreach (ImageCodecInfo c in codecs)
  8. {
  9. string codecName = c.CodecName.Substring(8).Replace("Codec", "Files").Trim();
  10. fdlg.Filter = string.Format("{0}{1}{2} ({3})|{3}", fdlg.Filter, "|", codecName, c.FilenameExtension);
  11. }
  12. // Code for files filter
  13. fdlg.Filter = fdlg.Filter + "|CSV Files (*.csv)|*.csv";
  14. fdlg.Filter = fdlg.Filter + "|Excel Files (.xls ,.xlsx)| *.xls ;*.xlsx";
  15. fdlg.Filter = fdlg.Filter + "|PDF Files (.pdf)|*.pdf";
  16. fdlg.Filter = fdlg.Filter + "|Text Files (*.txt)|*.txt";
  17. fdlg.Filter = fdlg.Filter + "|Word Files (.docx ,.doc)|*.docx;*.doc";
  18. fdlg.Filter = fdlg.Filter + "|XML Files (*.xml)|*.xml";
  20. fdlg.FilterIndex = 1;
  21. fdlg.RestoreDirectory = true;
  22. fdlg.Multiselect = true;
  23. if (fdlg.ShowDialog() == DialogResult.OK)
  24. {
  25. foreach (string file in fdlg.FileNames)
  26. {
  27. if (file != string.Empty)
  28. {
  29. DataRow drRow = dtData.NewRow();
  30. drRow["cname"] = Path.GetFileNameWithoutExtension(file);
  31. drRow["cpath"] = file;
  32. drRow["csaveto"] = strSavePath + RenameFile(file);
  33. dtData.Rows.Add(drRow);
  34. }
  35. }
  36. }
  37. dgvFile.DataSource = dtData;
Now, let us save them to a folder using File.Copy.
  1. File.Copy(oldPath, newPath, true);
Here is the complete code for FileUpload.cs file.
  1. using System;
  2. using System.IO;
  3. using System.Data;
  4. using System.Drawing.Imaging;
  5. using System.Windows.Forms;
  7. namespace FileUploads
  8. {
  9. public partial class FileUpload : Form
  10. {
  11. string strSavePath = @"D:\MyFolder\";
  12. DataTable dtData;
  14. public FileUpload()
  15. {
  16. InitializeComponent();
  17. }
  19. private void FileUpload_Load(object sender, EventArgs e)
  20. {
  21. dtData = CreateTable();
  22. }
  24. private DataTable CreateTable()
  25. {
  26. DataTable dtReturn = new DataTable();
  27. dtReturn.Columns.Add("cname", typeof(string));
  28. dtReturn.Columns.Add("cpath", typeof(string));
  29. dtReturn.Columns.Add("csaveto", typeof(string));
  30. return dtReturn;
  31. }
  33. private void btnSave_Click(object sender, EventArgs e)
  34. {
  35. if (dgvFile.Rows.Count > 0)
  36. {
  37. if (!Directory.Exists(strSavePath))
  38. {
  39. Directory.CreateDirectory(strSavePath);
  40. }
  41. int numRes = 0;
  42. for (int i = 0; i < dgvFile.Rows.Count; i++)
  43. {
  44. try
  45. {
  46. string oldPath = dgvFile.Rows[i].Cells["filePath"].Value.ToString();
  47. string fileSavePath = dgvFile.Rows[i].Cells["fileSavePath"].Value.ToString();
  48. File.Copy(oldPath, fileSavePath, true);
  49. numRes++;
  50. }
  51. catch { }
  52. }
  53. MessageBox.Show(numRes.ToString() + " nos of file saved !");
  54. dtData.Rows.Clear();
  55. dgvFile.DataSource = dtData;
  56. }
  57. }
  59. private void btnClear_Click(object sender, EventArgs e)
  60. {
  61. dtData.Rows.Clear();
  62. dgvFile.DataSource = dtData;
  63. }
  65. private void btnFile_Click(object sender, EventArgs e)
  66. {
  67. OpenFileDialog fdlg = new OpenFileDialog();
  68. fdlg.Title = "Select file";
  69. fdlg.InitialDirectory = Environment.SpecialFolder.Desktop.ToString();
  70. fdlg.Filter = string.Format("{0}{1}{2} ({3})|{3}", fdlg.Filter, "", "All Files", "*.*");
  71. // Code for image filter
  72. ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
  73. foreach (ImageCodecInfo c in codecs)
  74. {
  75. string codecName = c.CodecName.Substring(8).Replace("Codec", "Files").Trim();
  76. fdlg.Filter = string.Format("{0}{1}{2} ({3})|{3}", fdlg.Filter, "|", codecName, c.FilenameExtension);
  77. }
  78. // Code for files filter
  79. fdlg.Filter = fdlg.Filter + "|CSV Files (*.csv)|*.csv";
  80. fdlg.Filter = fdlg.Filter + "|Excel Files (.xls ,.xlsx)| *.xls ;*.xlsx";
  81. fdlg.Filter = fdlg.Filter + "|PDF Files (.pdf)|*.pdf";
  82. fdlg.Filter = fdlg.Filter + "|Text Files (*.txt)|*.txt";
  83. fdlg.Filter = fdlg.Filter + "|Word Files (.docx ,.doc)|*.docx;*.doc";
  84. fdlg.Filter = fdlg.Filter + "|XML Files (*.xml)|*.xml";
  86. fdlg.FilterIndex = 1;
  87. fdlg.RestoreDirectory = true;
  88. fdlg.Multiselect = true;
  89. if (fdlg.ShowDialog() == DialogResult.OK)
  90. {
  91. foreach (string file in fdlg.FileNames)
  92. {
  93. if (file != string.Empty)
  94. {
  95. DataRow drRow = dtData.NewRow();
  96. drRow["cname"] = Path.GetFileNameWithoutExtension(file);
  97. drRow["cpath"] = file;
  98. drRow["csaveto"] = strSavePath + RenameFile(file);
  99. dtData.Rows.Add(drRow);
  100. }
  101. }
  102. }
  103. dgvFile.DataSource = dtData;
  104. }
  106. public string RenameFile(string filePath)
  107. {
  108. string strExt = Path.GetExtension(filePath);
  109. string fileName = Guid.NewGuid().ToString("N") + strExt;
  110. return fileName;
  111. }
  112. }
  113. }
If you want to upload files from URL, then you can use WebClient.
  1. WebClient webClient = new WebClient();
  2. webClient.DownloadFileAsync(new Uri(oldPath), newPath);
Before that, you have to check if the given URL exists or not. For this, just call the URLExists method.
  1. public bool URLExists(string url)
  2. {
  3. bool result = true;
  4. try
  5. {
  6. WebRequest webRequest = WebRequest.Create(url);
  7. webRequest.Timeout = 1200; // miliseconds
  8. webRequest.Method = "HEAD";
  9. webRequest.GetResponse();
  10. }
  11. catch
  12. {
  13. result = false;
  14. }
  15. return result;
  16. }
By using these easy methods, we can upload a file or multiple files to a specific folder.

These simple tips may help beginner level readers to understand the concepts of uploading files to a folder.

Hope this will help you.