Argument exception - le paramètre n'est pas valide (LinkLabel on WinForm)

Question

J'ai créé une application Win Forms pour tester le fonctionnement d'une classe LinkLabel. Il semble aller bien jusqu'à ce que je clique sur le LinkLabel changé. Le code Form1.cs est ci-dessous:

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.Diagnostics; 

namespace LinkLabelTest 
{ 
// Editor: code not fully indented - laziness! 
public partial class Form1 : Form 
{ 

    public Form1() 
    { 
      InitializeComponent(); 
    } 

    private void btnLinkColor_Click(object sender, EventArgs e) 
    { 
     colorDialog1.ShowDialog(); 
     llblinkLabel1.LinkColor = colorDialog1.Color; 
    } 

    private void btnActiveLinkColor_Click(object sender, EventArgs e) 
    { 
     colorDialog1.ShowDialog(); 
     llblinkLabel1.ActiveLinkColor = colorDialog1.Color; 
    } 

    private void btnVisitedLinkColor_Click(object sender, EventArgs e) 
    { 
     colorDialog1.ShowDialog(); 
     llblinkLabel1.VisitedLinkColor = colorDialog1.Color; 
    } 

    private void llblinkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e) 
    { 

     try 
     { 

      if (!(e.Link.Description == null)) 
      { 
       if (e.Button == MouseButtons.Right) 
       { 
        PopulateLinkDetails(e.Link); 
       } 

       if (e.Button == MouseButtons.Left) 
       { 
        e.Link.Visited = true; 
        Debugger.Break(); 
       } 
      } 
     } 
     catch (Exception exc) 
     { 
      Debugger.Break(); 
      MessageBox.Show(exc.Message.ToString()); 
     } 
    } 

    private void PopulateLinkDetails(LinkLabel.Link link) 
    { 
     textDescription.Text = link.Description; 
     textLinkData.Text = (string)link.LinkData; 
     textName.Text = link.Name; 
     checkBoxEnabled.Checked = link.Enabled; 
     checkBoxVisited.Checked = link.Visited; 
     nudLinkAreaStart.Value = link.Start; 
     nudLinkAreaEnd.Value = link.Length; 
    } 


    private void Form1_Load(object sender, EventArgs e) 
    { 
      cmbLinkBehaviour.DataSource = Enum.GetValues(typeof(LinkBehavior)); 
    } 

    private void cmbLinkBehaviour_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     llblinkLabel1.LinkBehavior = (LinkBehavior)cmbLinkBehaviour.SelectedItem; 
    } 

    private void AddLink_Click(object sender, EventArgs e) 
    { 
      LinkLabel.Link link = new LinkLabel.Link(); 

      link.Description = textDescription.Text.ToString(); 
      link.LinkData = textLinkData.Text.ToString(); 
      link.Name = textName.Text.ToString(); 
      link.Enabled = checkBoxEnabled.Checked; 
      link.Visited = checkBoxVisited.Checked; 
      link.Start = (int)nudLinkAreaStart.Value; 
      link.Length = (int)nudLinkAreaEnd.Value; 

      llblinkLabel1.Links.Add(link); 
    } 

} 
} 

la trace de la pile est inférieure à:

à System.Drawing.Region.GetHrgn (Graphics g) à System.Windows.Forms.Control.Invalidate (région de région, Boolean invalidateChildren) à System.Windows.Forms.LinkLabel.InvalidateLink (lien de lien) à System.Windows.Forms.LinkLabel.OnGotFocus (EventArgs e) à System.Windows.Forms.Control.WmSetFocus (Message & m) à System.Windows.Form s.Control.WndProc (message & m) à System.Windows.Forms.Label.WndProc (message & m) à System.Windows.Forms.LinkLabel.WndProc (& message msg) à System.Windows.Forms. Control.ControlNativeWindow.OnMessage (message & m) à System.Windows.Forms.Control.ControlNativeWindow.WndProc (message & m) à System.Windows.Forms.NativeWindow.DebuggableCallback (IntPtr hWnd , Int32 msg, IntPtr wparam, IntPtr lparam) à System.Windows.Forms.UnsafeNativeMethods.SetFocus (HandleRef hWnd) à System.Windows.Forms.Control.FocusInternal() à System.Windows.Forms.LinkLabel.OnMouseDo wn (MouseEventArgs e) à System.Windows.Forms.Control.WmMouseDown (message & m, MouseButtons bouton , Int32 clique) à System.Windows.Forms.Control.WndProc (message & m) à System.Windows.Forms .Label.WndProc (message & m) à System.Windows.Forms.LinkLabel.WndProc (& message msg) à System.Windows.Forms.Control.ControlNativeWindow.OnMessage (message & m) à System.Windows.Forms .Control.ControlNativeWindow.WndProc (message & m) à System.Windows.Forms.NativeWindow.DebuggableCallback (IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) à System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW (MSG & msg) à System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop (Int32 dwComponentID, motif Int32, Int32 pvLoopData) à System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner (Int32 raison, le contexte ApplicationContext) à System.Windows.Forms.Application.ThreadContext.RunMessageLoop (Int32 raison, le contexte ApplicationContext) à System.Windows.Forms.Application .Run (Formulaire mainForm) à LinkLabelTest.Program.Main() dans C: \ Users \ Tony \ Documents \ Visual Studio 2008 \ Projects \ LinkLabelTest \ LinkLabelTest \ Program.cs: ligne 22

Ci-dessous le code généré concepteur:

using System.Diagnostics; 

namespace LinkLabelTest 
{ 
// Editor: code not fully indented - laziness again! 
partial class Form1 
{ 
    /// <summary> 
    /// Required designer variable. 
    /// </summary> 
    private System.ComponentModel.IContainer components = null; 

    /// <summary> 
    /// Clean up any resources being used. 
    /// </summary> 
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param> 
    protected override void Dispose(bool disposing) 
    { 
      if (disposing && (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.llblinkLabel1 = new System.Windows.Forms.LinkLabel(); 
     this.colorDialog1 = new System.Windows.Forms.ColorDialog(); 
     this.btnLinkColor = new System.Windows.Forms.Button(); 
     this.btnActiveLinkColor = new System.Windows.Forms.Button(); 
     this.btnVisitedLinkColor = new System.Windows.Forms.Button(); 
     this.nudLinkAreaStart = new System.Windows.Forms.NumericUpDown(); 
     this.lbllabel1 = new System.Windows.Forms.Label(); 
     this.nudLinkAreaEnd = new System.Windows.Forms.NumericUpDown(); 
     this.lbllabel2 = new System.Windows.Forms.Label(); 
     this.cmbLinkBehaviour = new System.Windows.Forms.ComboBox(); 
     this.lbllabel3 = new System.Windows.Forms.Label(); 
     this.groupBox1 = new System.Windows.Forms.GroupBox(); 
     this.textDescription = new System.Windows.Forms.TextBox(); 
     this.label1 = new System.Windows.Forms.Label(); 
     this.textName = new System.Windows.Forms.TextBox(); 
     this.label2 = new System.Windows.Forms.Label(); 
     this.label3 = new System.Windows.Forms.Label(); 
     this.textLinkData = new System.Windows.Forms.TextBox(); 
     this.label4 = new System.Windows.Forms.Label(); 
     this.checkBoxEnabled = new System.Windows.Forms.CheckBox(); 
     this.AddLink = new System.Windows.Forms.Button(); 
     this.btnAmendLink = new System.Windows.Forms.Button(); 
     this.checkBoxVisited = new System.Windows.Forms.CheckBox(); 
     this.panel1 = new System.Windows.Forms.Panel(); 
     this.textBox1 = new System.Windows.Forms.TextBox(); 
     ((System.ComponentModel.ISupportInitialize)(this.nudLinkAreaStart)).BeginInit(); 
     ((System.ComponentModel.ISupportInitialize)(this.nudLinkAreaEnd)).BeginInit(); 
     this.groupBox1.SuspendLayout(); 
     this.panel1.SuspendLayout(); 
     this.SuspendLayout(); 
     // 
     // llblinkLabel1 
     // 
     this.llblinkLabel1.AutoSize = true; 
     this.llblinkLabel1.Location = new System.Drawing.Point(13, 27); 
     this.llblinkLabel1.Name = "llblinkLabel1"; 
     this.llblinkLabel1.Size = new System.Drawing.Size(96, 13); 
     this.llblinkLabel1.TabIndex = 0; 
     this.llblinkLabel1.TabStop = true; 
     this.llblinkLabel1.Text = "This is a link label !"; 
     this.llblinkLabel1.LinkClicked += new System.Windows.Forms.LinkLabelLinkClickedEventHandler(this.llblinkLabel1_LinkClicked); 
     // 
     // btnLinkColor 
     // 
     this.btnLinkColor.Location = new System.Drawing.Point(0, 19); 
     this.btnLinkColor.Name = "btnLinkColor"; 
     this.btnLinkColor.Size = new System.Drawing.Size(93, 23); 
     this.btnLinkColor.TabIndex = 2; 
     this.btnLinkColor.Text = "LinkColor"; 
     this.btnLinkColor.UseVisualStyleBackColor = true; 
     this.btnLinkColor.Click += new System.EventHandler(this.btnLinkColor_Click); 
     // 
     // btnActiveLinkColor 
     // 
     this.btnActiveLinkColor.Location = new System.Drawing.Point(0, 48); 
     this.btnActiveLinkColor.Name = "btnActiveLinkColor"; 
     this.btnActiveLinkColor.Size = new System.Drawing.Size(93, 23); 
     this.btnActiveLinkColor.TabIndex = 3; 
     this.btnActiveLinkColor.Text = "ActiveLinkColor"; 
     this.btnActiveLinkColor.UseVisualStyleBackColor = true; 
     this.btnActiveLinkColor.Click += new System.EventHandler(this.btnActiveLinkColor_Click); 
     // 
     // btnVisitedLinkColor 
     // 
     this.btnVisitedLinkColor.Location = new System.Drawing.Point(0, 77); 
     this.btnVisitedLinkColor.Name = "btnVisitedLinkColor"; 
     this.btnVisitedLinkColor.Size = new System.Drawing.Size(93, 23); 
     this.btnVisitedLinkColor.TabIndex = 4; 
     this.btnVisitedLinkColor.Text = "VisitedLinkColor"; 
     this.btnVisitedLinkColor.UseVisualStyleBackColor = true; 
     this.btnVisitedLinkColor.Click += new System.EventHandler(this.btnVisitedLinkColor_Click); 
     // 
     // nudLinkAreaStart 
     // 
     this.nudLinkAreaStart.Location = new System.Drawing.Point(152, 64); 
     this.nudLinkAreaStart.Maximum = new decimal(new int[] { 
     21, 
     0, 
     0, 
     0}); 
     this.nudLinkAreaStart.Name = "nudLinkAreaStart"; 
     this.nudLinkAreaStart.Size = new System.Drawing.Size(66, 20); 
     this.nudLinkAreaStart.TabIndex = 6; 
     // 
     // lbllabel1 
     // 
     this.lbllabel1.AutoSize = true; 
     this.lbllabel1.Location = new System.Drawing.Point(224, 71); 
     this.lbllabel1.Name = "lbllabel1"; 
     this.lbllabel1.Size = new System.Drawing.Size(74, 13); 
     this.lbllabel1.TabIndex = 7; 
     this.lbllabel1.Text = "Link area start"; 
     // 
     // nudLinkAreaEnd 
     // 
     this.nudLinkAreaEnd.Location = new System.Drawing.Point(152, 99); 
     this.nudLinkAreaEnd.Maximum = new decimal(new int[] { 
     21, 
     0, 
     0, 
     0}); 
     this.nudLinkAreaEnd.Name = "nudLinkAreaEnd"; 
     this.nudLinkAreaEnd.Size = new System.Drawing.Size(67, 20); 
     this.nudLinkAreaEnd.TabIndex = 8; 
     // 
     // lbllabel2 
     // 
     this.lbllabel2.AutoSize = true; 
     this.lbllabel2.Location = new System.Drawing.Point(224, 105); 
     this.lbllabel2.Name = "lbllabel2"; 
     this.lbllabel2.Size = new System.Drawing.Size(83, 13); 
     this.lbllabel2.TabIndex = 9; 
     this.lbllabel2.Text = "Link area length"; 
     // 
     // cmbLinkBehaviour 
     // 
     this.cmbLinkBehaviour.FormattingEnabled = true; 
     this.cmbLinkBehaviour.Location = new System.Drawing.Point(0, 106); 
     this.cmbLinkBehaviour.Name = "cmbLinkBehaviour"; 
     this.cmbLinkBehaviour.Size = new System.Drawing.Size(93, 21); 
     this.cmbLinkBehaviour.TabIndex = 10; 
     this.cmbLinkBehaviour.SelectedIndexChanged += new System.EventHandler(this.cmbLinkBehaviour_SelectedIndexChanged); 
     // 
     // lbllabel3 
     // 
     this.lbllabel3.AutoSize = true; 
     this.lbllabel3.Location = new System.Drawing.Point(-3, 130); 
     this.lbllabel3.Name = "lbllabel3"; 
     this.lbllabel3.Size = new System.Drawing.Size(78, 13); 
     this.lbllabel3.TabIndex = 11; 
     this.lbllabel3.Text = "Link Behaviour"; 
     // 
     // groupBox1 
     // 
     this.groupBox1.Controls.Add(this.btnLinkColor); 
     this.groupBox1.Controls.Add(this.btnActiveLinkColor); 
     this.groupBox1.Controls.Add(this.lbllabel3); 
     this.groupBox1.Controls.Add(this.btnVisitedLinkColor); 
     this.groupBox1.Controls.Add(this.cmbLinkBehaviour); 
     this.groupBox1.Location = new System.Drawing.Point(12, 57); 
     this.groupBox1.Name = "groupBox1"; 
     this.groupBox1.Size = new System.Drawing.Size(124, 155); 
     this.groupBox1.TabIndex = 13; 
     this.groupBox1.TabStop = false; 
     this.groupBox1.Text = "THE link label"; 
     // 
     // textDescription 
     // 
     this.textDescription.Location = new System.Drawing.Point(152, 136); 
     this.textDescription.Name = "textDescription"; 
     this.textDescription.Size = new System.Drawing.Size(100, 20); 
     this.textDescription.TabIndex = 14; 
     // 
     // label1 
     // 
     this.label1.AutoSize = true; 
     this.label1.Location = new System.Drawing.Point(259, 143); 
     this.label1.Name = "label1"; 
     this.label1.Size = new System.Drawing.Size(60, 13); 
     this.label1.TabIndex = 15; 
     this.label1.Text = "Description"; 
     // 
     // textName 
     // 
     this.textName.Location = new System.Drawing.Point(152, 163); 
     this.textName.Name = "textName"; 
     this.textName.Size = new System.Drawing.Size(100, 20); 
     this.textName.TabIndex = 16; 
     // 
     // label2 
     // 
     this.label2.AutoSize = true; 
     this.label2.Location = new System.Drawing.Point(262, 170); 
     this.label2.Name = "label2"; 
     this.label2.Size = new System.Drawing.Size(35, 13); 
     this.label2.TabIndex = 17; 
     this.label2.Text = "Name"; 
     // 
     // label3 
     // 
     this.label3.AutoSize = true; 
     this.label3.Location = new System.Drawing.Point(16, 11); 
     this.label3.Name = "label3"; 
     this.label3.Size = new System.Drawing.Size(283, 13); 
     this.label3.TabIndex = 18; 
     this.label3.Text = "Right Click on a link to retrieve properties. Left Click to visit"; 
     // 
     // textLinkData 
     // 
     this.textLinkData.Location = new System.Drawing.Point(152, 191); 
     this.textLinkData.Name = "textLinkData"; 
     this.textLinkData.Size = new System.Drawing.Size(100, 20); 
     this.textLinkData.TabIndex = 19; 
     // 
     // label4 
     // 
     this.label4.AutoSize = true; 

     this.label4.Location = new System.Drawing.Point(262, 198); 
     this.label4.Name = "label4"; 
     this.label4.Size = new System.Drawing.Size(53, 13); 
     this.label4.TabIndex = 20; 
     this.label4.Text = "Link Data"; 
     // 
     // checkBoxEnabled 
     // 
     this.checkBoxEnabled.AutoSize = true; 
     this.checkBoxEnabled.Location = new System.Drawing.Point(151, 218); 
     this.checkBoxEnabled.Name = "checkBoxEnabled"; 
     this.checkBoxEnabled.Size = new System.Drawing.Size(65, 17); 
     this.checkBoxEnabled.TabIndex = 21; 
     this.checkBoxEnabled.Text = "Enabled"; 
     this.checkBoxEnabled.UseVisualStyleBackColor = true; 
     // 
     // AddLink 
     // 
     this.AddLink.Location = new System.Drawing.Point(385, 64); 
     this.AddLink.Name = "AddLink"; 
     this.AddLink.Size = new System.Drawing.Size(75, 23); 
     this.AddLink.TabIndex = 22; 
     this.AddLink.Text = "Add Link"; 
     this.AddLink.UseVisualStyleBackColor = true; 
     this.AddLink.Click += new System.EventHandler(this.AddLink_Click); 
     // 
     // btnAmendLink 
     // 
     this.btnAmendLink.Enabled = false; 
     this.btnAmendLink.Location = new System.Drawing.Point(385, 99); 
     this.btnAmendLink.Name = "btnAmendLink"; 
     this.btnAmendLink.Size = new System.Drawing.Size(75, 23); 
     this.btnAmendLink.TabIndex = 23; 
     this.btnAmendLink.Text = "AmendLink"; 
     this.btnAmendLink.UseVisualStyleBackColor = true; 
     // 
     // checkBoxVisited 
     // 
     this.checkBoxVisited.AutoSize = true; 
     this.checkBoxVisited.Location = new System.Drawing.Point(151, 241); 
     this.checkBoxVisited.Name = "checkBoxVisited"; 
     this.checkBoxVisited.Size = new System.Drawing.Size(57, 17); 
     this.checkBoxVisited.TabIndex = 24; 
     this.checkBoxVisited.Text = "Visited"; 
     this.checkBoxVisited.UseVisualStyleBackColor = true; 
     // 
     // panel1 
     // 
     this.panel1.Controls.Add(this.textBox1); 
     this.panel1.Location = new System.Drawing.Point(474, 13); 
     this.panel1.Name = "panel1"; 
     this.panel1.Size = new System.Drawing.Size(200, 239); 
     this.panel1.TabIndex = 25; 
     // 
     // textBox1 
     // 
     this.textBox1.Dock = System.Windows.Forms.DockStyle.Fill; 
     this.textBox1.Location = new System.Drawing.Point(0, 0); 
     this.textBox1.Multiline = true; 
     this.textBox1.Name = "textBox1"; 
     this.textBox1.Size = new System.Drawing.Size(200, 239); 
     this.textBox1.TabIndex = 0; 
     // 
     // Form1 
     // 
     this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); 
     this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; 
     this.ClientSize = new System.Drawing.Size(704, 264); 
     this.Controls.Add(this.panel1); 
     this.Controls.Add(this.checkBoxVisited); 
     this.Controls.Add(this.btnAmendLink); 
     this.Controls.Add(this.AddLink); 
     this.Controls.Add(this.checkBoxEnabled); 
     this.Controls.Add(this.label4); 
     this.Controls.Add(this.textLinkData); 
     this.Controls.Add(this.label3); 
     this.Controls.Add(this.label2); 
     this.Controls.Add(this.textName); 
     this.Controls.Add(this.label1); 
     this.Controls.Add(this.textDescription); 
     this.Controls.Add(this.groupBox1); 
     this.Controls.Add(this.lbllabel2); 
     this.Controls.Add(this.nudLinkAreaEnd); 
     this.Controls.Add(this.lbllabel1); 
     this.Controls.Add(this.nudLinkAreaStart); 
     this.Controls.Add(this.llblinkLabel1); 
     this.Name = "Form1"; 
     this.Text = "Form1"; 
     this.Load += new System.EventHandler(this.Form1_Load); 
     ((System.ComponentModel.ISupportInitialize)(this.nudLinkAreaStart)).EndInit(); 
     ((System.ComponentModel.ISupportInitialize)(this.nudLinkAreaEnd)).EndInit(); 
     this.groupBox1.ResumeLayout(false); 
     this.groupBox1.PerformLayout(); 
     this.panel1.ResumeLayout(false); 
     this.panel1.PerformLayout(); 
     this.ResumeLayout(false); 
     this.PerformLayout(); 

    } 

    #endregion 

    private System.Windows.Forms.LinkLabel llblinkLabel1; 
    private System.Windows.Forms.ColorDialog colorDialog1; 
    private System.Windows.Forms.Button btnLinkColor; 
    private System.Windows.Forms.Button btnActiveLinkColor; 
    private System.Windows.Forms.Button btnVisitedLinkColor; 
    private System.Windows.Forms.NumericUpDown nudLinkAreaStart; 
    private System.Windows.Forms.Label lbllabel1; 
    private System.Windows.Forms.NumericUpDown nudLinkAreaEnd; 
    private System.Windows.Forms.Label lbllabel2; 
    private System.Windows.Forms.ComboBox cmbLinkBehaviour; 
    private System.Windows.Forms.Label lbllabel3; 
    private System.Windows.Forms.GroupBox groupBox1; 
    private System.Windows.Forms.TextBox textDescription; 
    private System.Windows.Forms.Label label1; 
    private System.Windows.Forms.TextBox textName; 
    private System.Windows.Forms.Label label2; 
    private System.Windows.Forms.Label label3; 
    private System.Windows.Forms.TextBox textLinkData; 
    private System.Windows.Forms.Label label4; 
    private System.Windows.Forms.CheckBox checkBoxEnabled; 
    private System.Windows.Forms.Button AddLink; 
    private System.Windows.Forms.Button btnAmendLink; 
    private System.Windows.Forms.CheckBox checkBoxVisited; 
    private System.Windows.Forms.Panel panel1; 
    private System.Windows.Forms.TextBox textBox1; 
} 
} 

S'il vous plaît quelqu'un peut-il conseiller. Est le problème qu'il n'y a aucun handle de Windows pour le LinkLabel lorsque son événement Paint se produit.

Un grand merci à l'avance

Tony

Answer 1

Le code exemple suivant montre comment vous pouvez définir la couleur d'étiquette de lien d'un ColorDialog:

using (var colorDlg = new ColorDialog()) 
{ 
    if (colorDlg.ShowDialog() == DialogResult.OK) 
    { 
     llblinkLabel1.LinkColor = colorDlg.Color; 
    } 
} 

Answer 2

private void AddLink_Click(object sender, EventArgs e) 
    { 
     // do proper validation and add only proper links 
     // this will help you to avoid the exception 
     if (!string.IsNullOrEmpty(textLinkData.Text) && 
      nudLinkAreaEnd.Value > 0 && 
      nudLinkAreaStart.Value >= 0 && 
      nudLinkAreaStart.Value < llblinkLabel1.Text.Length) 
     { 
      LinkLabel.Link link = new LinkLabel.Link(); 
      link.Description = textDescription.Text.ToString(); 
      link.LinkData = textLinkData.Text.ToString(); 
      link.Name = textName.Text.ToString(); 
      link.Enabled = checkBoxEnabled.Checked; 
      link.Visited = checkBoxVisited.Checked; 
      link.Start = (int)nudLinkAreaStart.Value; 
      link.Length = (int)nudLinkAreaEnd.Value; 
      try 
      { 
       llblinkLabel1.Links.Add(link); 
      } 
      catch (InvalidOperationException exception) // links can't overlap 
      { 
       MessageBox.Show("Links are overlaping"); 
      } 

     }