A simple file MD5 code automatically calculates the comparator (with source code)

I am not particularly clear about how to update winform with multiple threads. The Code is as follows. Thank you for your advice!

Copy codeThe Code is as follows:
Using System;
Using System. Collections. Generic;
Using System. ComponentModel;
Using System. Data;
Using System. Drawing;
Using System. Linq;
Using System. Text;
Using System. Windows. Forms;
Using System. Security. Cryptography;
Using System. IO;
Using System. Threading;

Namespace FileMD5 {
Public partial class MainForm: Form {
Public MainForm (){
InitializeComponent ();
}

Private void button_file_Click (object sender, EventArgs e ){
OpenFileDialog fileDialog = new OpenFileDialog ();
FileDialog. Title = "select a file ";
FileDialog. RestoreDirectory = true;

If (fileDialog. ShowDialog () = DialogResult. OK ){
TextBox_file.Text = fileDialog. FileName;
TextBox_result.Text = "";
FileInfo file = new FileInfo (fileDialog. FileName );
FileSzie = file. Length;
ShowFilesize (fileSzie );
}

}

Private void button_exit_Click (object sender, EventArgs e ){
This. Close ();
This. Dispose ();
}

Private void button_check_Click (object sender, EventArgs e ){
CheckResult ();
}

MD5 md5 = (MD5) CryptoConfig. CreateFromName ("MD5 ");
Long fileSzie = 0;

Private void button_calc_Click (object sender, EventArgs e ){
String file = textBox_file.Text;

If (file. Length = 0 ){
TextBox_result.Text = "Please reselect the file first! ";
Return;
}

FileStream fs = null;
Try {
Fs = new FileStream (file, FileMode. Open, FileAccess. Read );
} Catch (SystemException ){
TextBox_result.Text = "An error occurred while opening the file. Please reselect the file! ";
Return;
}

// Enable multithreading for files larger than 100 MB
If (fs. Length> 100L * 1024*1024 ){

String message = "the file has exceeded 100 MB, which takes a long time to calculate. \ N software will start the background thread for processing. Continue? ";
String caption = "large files ";
MessageBoxButtons buttons = MessageBoxButtons. YesNo;

If (MessageBox. Show (message, caption, buttons) = System. Windows. Forms. DialogResult. No ){
Fs. Close ();
TextBox_result.Text = "the file is large and not computed. ";
Return;
}
TextBox_result.Text = "computing... please wait ......";
Button_calc.Enabled = false;
Button_file.Enabled = false;

Thread thread = new Thread (new ParameterizedThreadStart (calizer 5 ));
Thread. Start (fs );

} Else {
Cal1_5 (fs );
}
}

// Create an object Parameter Function to handle the use of parameters in thread calls.
Private void cal00005 (object fs ){
Cal12005 (FileStream) fs );
}

// Delegate used by the Invoke Function
Delegate void updateWindows (byte [] result );

Private void cal00005 (FileStream fs ){
Byte [] md5byte = md5.ComputeHash (fs );

If (this. InvokeRequired ){
This. Invoke (new updateWindows (showResult), md5byte );
} Else {
ShowResult (md5byte );
}
Fs. Close ();
}

Private void showResult (byte [] md5byte ){
Int I, j;
StringBuilder sb = new StringBuilder (32 );
Foreach (byte B in md5byte ){
I = Convert. ToInt32 (B );
J = I> 4;
Sb. Append (Convert. ToString (j, 16 ));
J = (I <4) & 0x00ff)> 4;
Sb. Append (Convert. ToString (j, 16 ));
}

String result = sb. ToString (). ToUpper ();

TextBox_result.Text = result;
Button_calc.Enabled = true;
Button_file.Enabled = true;
CheckResult ();

}

Private void checkResult (){

String result = textBox_result.Text;

If (textBox_md5.Text.Length = 0 ){
TextBox_compare.Text = "";
TextBox_compare.Visible = false;
Return;
}

If (result. Length! = 32 ){
TextBox_compare.Visible = true;
TextBox_compare.BackColor = Color. Pink;
TextBox_compare.Text = "the calculated result box is not an MD5 code. Perform calculation first! ";
Return;
}

If (textBox_md5.Text.Trim (). ToUpper (). Equals (result. ToUpper ())){
TextBox_compare.Visible = true;
TextBox_compare.BackColor = Color. LightGreen;
TextBox_compare.Text = "the MD5 code has been matched and the file has not been modified. You can use it with confidence! ";
} Else {
TextBox_compare.Visible = true;
TextBox_compare.BackColor = Color. Red;
TextBox_compare.Text = "the MD5 Code does not match. The file has been modified. Please be careful! ";
}
}

Private void showFilesize (long size ){

Float d_size;
String unit = "Byte ";

If (size> 1024*1024*1024) {// display greater than 1G
D_size = size/(float) (1024*1024*1024 );
Unit = "GB ";
} Else {
If (size> 1024*1024) {// display greater than 1 M
D_size = size/(float) (1024*1024 );
Unit = "MB ";
} Else {
If (size> 1024) {// display greater than 1 K
D_size = size/(float) (1024 );
Unit = "KB ";
} Else {
D_size = size;
}
}
}
TextBox_filesize.Text = string. Format ("{0: F} {1} ({2: N0} bytes)", d_size, unit, size );
}
}
}

Complete VS2010 project download: http://xiazai.jb51.net/201302/yuanma/FileMD5_jb51.net.rar