how to pass variable value in event handler

Question

Hi I am beginner in C#. In for loop  I am creating panel control with Image inside (calling 10 images)When I click on image  it should display value of that Image (Image number) using pop up message box. Please suggest code for the same public Form1() { InitializeComponent(); System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1)); for (int count = 1; count { this.panel1 = new System.Windows.Forms.Panel(); // panel1 this.panel1.BackgroundImage = Image.FromFile(Application.StartupPath + \activecell.jpg); this.panel1.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Center; this.panel1.Location = new System.Drawing.Point(50 50); this.panel1.Name = panel1 + count; this.panel1.Size = new System.Drawing.Size(70 35); this.panel1.Click += new System.EventHandler(this.panel1_Click); this.flowLayoutPanel1.Controls.Add(this.panel1); } } private void panel1_Click(object sender EventArgs e) { } as I can not pass count variable to panel1_Click variable and i want to display count value on message box. please reply regards Viva

Vulpes · Answer

If you want to pass any variable at all to the handler then you can set the panel's Tag property which is of type object and so an accept a value of any type: public Form1() { InitializeComponent(); System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1)); for (int count = 1; count { this.panel1 = new System.Windows.Forms.Panel(); this.panel1.Name = Image + count.ToString(); this.panel1.Tag = whatever; // panel1 this.panel1.BackgroundImage = Image.FromFile(Application.StartupPath + \activecell.jpg); this.panel1.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Center; this.panel1.Location = new System.Drawing.Point(50 50); this.panel1.Name = panel1 + count; this.panel1.Size = new System.Drawing.Size(70 35); this.panel1.Click += new System.EventHandler(this.panel1_Click); this.flowLayoutPanel1.Controls.Add(this.panel1); } } private void panel1_Click(object sender EventArgs e) { Panel p = (Panel)sender; string number = p.Name.Substring(5); string tag = p.Tag.ToString(); MessageBox.Show(Image  + number +  clicked with tag  + tag); }

viva · Answer

Thank u very much for your quick reply. It is working

Vulpes · Answer

If you know that the Tag property will contain an integer then you can cast it to one before doing any arithmetic or arithmetic comparisons: Panel p = (Panel)sender; string number = p.Name.Substring(5); int tag = (int)p.Tag; if (tag MessageBox.Show(Image  + number +  is active); else MessageBox.Show(Image  + number +  is disabled);

viva · Answer

but now in the same event I want to compare to display different messages. Panel p = (Panel)sender; string number = p.Name.Substring(5); string tag = p.Tag.ToString(); if (tag MessageBox.Show(Image  + number +  is active); else MessageBox.Show(Image  + number +  is disable); but for red mark code I am getting error as operator can not be applied to operands of type string to int

viva · Answer

ok I got it by doing this.panel1.Tag = count; thank u very much

viva · Answer

by doing this i am getting count as string.But i want the value of that count??

viva · Answer

Hi Thanks for the reply. It is working. But I want to pass any variable value declare in public Form1() to that event.How to do that? suppose there is other for loop inside running and want to pass that value.how to pass integer?? Viva

Vulpes · Answer

Try this: public Form1() { InitializeComponent(); System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1)); for (int count = 1; count { this.panel1 = new System.Windows.Forms.Panel(); this.panel1.Name = Image + count.ToString(); // panel1 this.panel1.BackgroundImage = Image.FromFile(Application.StartupPath + \activecell.jpg); this.panel1.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Center; this.panel1.Location = new System.Drawing.Point(50 50); this.panel1.Name = panel1 + count; this.panel1.Size = new System.Drawing.Size(70 35); this.panel1.Click += new System.EventHandler(this.panel1_Click); this.flowLayoutPanel1.Controls.Add(this.panel1); } } private void panel1_Click(object sender EventArgs e) { Panel p = (Panel)sender; string number = p.Name.Substring(5); MessageBox.Show(Image  + number +  clicked); }