Problem med en "tråd" (thread) får NullReferenceException!
Jeg vil ikke prøve at beskrive det... er ikke alt for "sharp" til C# :)-----------------------------------------------------------------
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;
namespace MyToolbar
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.Button button1;
private System.Windows.Forms.Button button2;
private System.Threading.Thread t;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#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.label1 = new System.Windows.Forms.Label();
this.label2 = new System.Windows.Forms.Label();
this.textBox1 = new System.Windows.Forms.TextBox();
this.textBox2 = new System.Windows.Forms.TextBox();
this.button1 = new System.Windows.Forms.Button();
this.button2 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// label1
//
this.label1.Location = new System.Drawing.Point(8, 8);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(80, 16);
this.label1.TabIndex = 0;
this.label1.Text = "Screen width:";
//
// label2
//
this.label2.Location = new System.Drawing.Point(128, 8);
this.label2.Name = "label2";
this.label2.Size = new System.Drawing.Size(80, 16);
this.label2.TabIndex = 1;
this.label2.Text = "Screen height:";
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(8, 24);
this.textBox1.Name = "textBox1";
this.textBox1.TabIndex = 2;
this.textBox1.Text = "";
//
// textBox2
//
this.textBox2.Location = new System.Drawing.Point(128, 24);
this.textBox2.Name = "textBox2";
this.textBox2.TabIndex = 3;
this.textBox2.Text = "";
//
// button1
//
this.button1.Location = new System.Drawing.Point(8, 56);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(128, 23);
this.button1.TabIndex = 4;
this.button1.Text = "Get screen dimensions";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// button2
//
this.button2.Location = new System.Drawing.Point(8, 88);
this.button2.Name = "button2";
this.button2.Size = new System.Drawing.Size(224, 32);
this.button2.TabIndex = 5;
this.button2.Text = "Exit";
this.button2.Click += new System.EventHandler(this.button2_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(240, 549);
this.Controls.Add(this.button2);
this.Controls.Add(this.button1);
this.Controls.Add(this.textBox2);
this.Controls.Add(this.textBox1);
this.Controls.Add(this.label2);
this.Controls.Add(this.label1);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.Name = "Form1";
this.Text = "Form1";
this.TopMost = true;
this.Width = 240;
this.Load += new System.EventHandler(this.Form1_Load);
this.MouseEnter += new System.EventHandler(this.Form1_MouseEnter);
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
public void Form1_MouseEnter(object sender, System.EventArgs e)
{
ShowToolbar();
Thread t = new Thread(new ThreadStart(GetMousePosition));
t.Name = "mpThread";
t.IsBackground = true;
t.Start();
}
private void Form1_Load(object sender, System.EventArgs e)
{
HideToolbar();
}
private void button1_Click(object sender, System.EventArgs e)
{
textBox1.Text = Screen.PrimaryScreen.WorkingArea.Width.ToString();
textBox2.Text = Screen.PrimaryScreen.WorkingArea.Height.ToString();
}
private void button2_Click(object sender, System.EventArgs e)
{
this.Close();
}
private void GetMousePosition()
{
Point MousePosition = new Point();
while(true)
{
if(Control.MousePosition.X < this.Location.X)
{
HideToolbar();
try
{
t.Abort();
}
catch(Exception ex)
{
MessageBox.Show("Error: "+ex);
}
}
else
{
this.ShowToolbar();
}
}
}
private void ShowToolbar()
{
this.Location = new Point(Screen.PrimaryScreen.WorkingArea.Width - 240, 0);
}
private void HideToolbar()
{
this.Height = Screen.PrimaryScreen.WorkingArea.Height;
this.Location = new Point(Screen.PrimaryScreen.WorkingArea.Width -10, 0);
}
}
}
----------------------------------------------------------------
Får følgende fejl:
System.NullReferenceException: Object reference not set to an instance of an object at MyToolbar.Form1.GetMousePosition() in ... line 187 -> t.Abort();
- Håber nogen kan forklare mig hvad jeg har gjort galt :)
