Threads, textboxes and scrolling
Thanks in advance for any information on this matter. I have run into
a small richtextbox, scrolling and tread issue. Which has me totally
confused. Instead of trying to explain it I wrote some small C# code
to demonstrate the fact that in the threaded version the textbox
simple doesn't scroll like it should… please look to the
startButton_Click method for the distinction between the two
programs..
Thanks
Wesley
why does this work ?????????????
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.IO;
using System.Data;
namespace Test
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Test : System.Windows.Forms.Form
{
const string newline = "\r\n";
/// <summary>
/// Required designer variable.
/// </summary>
private System.Windows.Forms.Button startButton;
private System.Windows.Forms.RichTextBox output;
private System.ComponentModel.Container components = null;
public Test()
{
InitializeComponent();
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Test());
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.startButton = new System.Windows.Forms.Button();
this.output = new System.Windows.Forms.RichTextBox();
this.SuspendLayout();
//
// startButton
//
this.startButton.Anchor = (System.Windows.Forms.AnchorStyles.Top |
System.Windows.Forms.AnchorStyles.Right);
this.startButton.Location = new System.Drawing.Point(424, 8);
this.startButton.Name = "startButton";
this.startButton.TabIndex = 0;
this.startButton.Text = "Start";
this.startButton.Click += new
System.EventHandler(this.startButton_Click);
//
// output
//
this.output.Anchor = (((System.Windows.Forms.AnchorStyles.Top |
System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.output.Location = new System.Drawing.Point(0, 40);
this.output.Name = "output";
this.output.Size = new System.Drawing.Size(512, 296);
this.output.TabIndex = 1;
this.output.Text = "";
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(512, 334);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.output,
this.startButton});
this.Name = "Form1";
this.Text = "Backup Utility";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// this method takes the giving string and writes it to the
richtextbox.
/// this method appends a new line at the end of the input string to
facilite
/// returns and scrolling to the botton.. callers need not add a
newline.
/// </summary>
/// <param name="msg">string</param>
private void DisplayNewEvent(string msg)
{
output.AppendText(msg + newline);
output.Focus();
output.SelectionStart = output.Text.Length + 1;
output.SelectionLength = 0;
output.ScrollToCaret();
}
private void startButton_Click(object sender, System.EventArgs e)
{
GoThroughMyDocuments();
}
/// <summary>
/// this functions goes through all the folders and files and places
the
/// filename in the richtext box...
/// </summary>
private void GoThroughMyDocuments()
{
DirectoryInfo info = new DirectoryInfo(
@"C:\Documents and Settings\" +
SystemInformation.UserName +
@"\My Documents");
RecursivelyTransverseFilesAndFolders(info.GetDirec tories());
GetFileName(info.GetFiles());
}
//recursively find all the files in all directories in "My
Documents"
private void RecursivelyTransverseFilesAndFolders(DirectoryInfo[]
directories)
{
if(directories!=null)
foreach(DirectoryInfo dir in directories)
{
RecursivelyTransverseFilesAndFolders(dir.GetDirect ories());
GetFileName(dir.GetFiles());
}
}
// get each file name and print its full path to the text box
private void GetFileName(FileInfo[] info)
{
if(info!=null)
foreach(FileInfo file in info)
DisplayNewEvent(file.FullName);
}
}
}
and this not work??????????
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.IO;
using System.Data;
using System.Threading;
namespace ThreadTest
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class ThreadTest : System.Windows.Forms.Form
{
const string newline = "\r\n";
Thread worker1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.Windows.Forms.Button startButton;
private System.Windows.Forms.RichTextBox output;
private System.ComponentModel.Container components = null;
public ThreadTest()
{
InitializeComponent();
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new ThreadTest());
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.startButton = new System.Windows.Forms.Button();
this.output = new System.Windows.Forms.RichTextBox();
this.SuspendLayout();
//
// startButton
//
this.startButton.Anchor = (System.Windows.Forms.AnchorStyles.Top |
System.Windows.Forms.AnchorStyles.Right);
this.startButton.Location = new System.Drawing.Point(424, 8);
this.startButton.Name = "startButton";
this.startButton.TabIndex = 0;
this.startButton.Text = "Start";
this.startButton.Click += new
System.EventHandler(this.startButton_Click);
//
// output
//
this.output.Anchor = (((System.Windows.Forms.AnchorStyles.Top |
System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.output.Location = new System.Drawing.Point(0, 40);
this.output.Name = "output";
this.output.Size = new System.Drawing.Size(512, 296);
this.output.TabIndex = 1;
this.output.Text = "";
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(512, 334);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.output,
this.startButton});
this.Name = "Form1";
this.Text = "Backup Utility";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// this method takes the giving string and writes it to the
richtextbox.
/// this method appends a new line at the end of the input string to
facilite
/// returns and scrolling to the botton.. callers need not add a
newline.
/// </summary>
/// <param name="msg">string</param>
private void DisplayNewEvent(string msg)
{
output.AppendText(msg + newline);
output.Focus();
output.SelectionStart = output.Text.Length + 1;
output.SelectionLength = 0;
output.ScrollToCaret();
}
private void startButton_Click(object sender, System.EventArgs e)
{
worker1 = new Thread(new ThreadStart(GoThroughMyDocuments));
worker1.Start();
// primary thread continues its execution while the worker goes
// throught its laborous task.
}
/// <summary>
/// this functions goes through all the folders and files and places
the
/// filename in the richtext box...
/// </summary>
private void GoThroughMyDocuments()
{
DirectoryInfo info = new DirectoryInfo(
@"C:\Documents and Settings\" +
SystemInformation.UserName +
@"\My Documents");
RecursivelyTransverseFilesAndFolders(info.GetDirec tories());
GetFileName(info.GetFiles());
worker1.Abort();
}
//recursively find all the files in all directories in "My
Documents"
private void RecursivelyTransverseFilesAndFolders(DirectoryInfo[]
directories)
{
if(directories!=null)
foreach(DirectoryInfo dir in directories)
{
RecursivelyTransverseFilesAndFolders(dir.GetDirect ories());
GetFileName(dir.GetFiles());
}
}
// get each file name and print its full path to the text box
private void GetFileName(FileInfo[] info)
{
if(info!=null)
foreach(FileInfo file in info)
DisplayNewEvent(file.FullName);
}
}
}
