asked on

how to scale graphicspath to match picturebox zoom

I have a picturebox on a form. I load an image into it at runtime. Then i create an array of grphicpaths to outline several shapes on the image.

But often the image needs to be stretched to fill fill the form. When this happens the pre saved graphics paths no longer line up with their corresponding shape. I am guessing that I need to scale the paths, but how do I know how much to scale them?

ASKER CERTIFIED SOLUTION

Robert Schutt

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Robert Schutt

Here is the designer code, in case you want to replicate the test program:

namespace EE_Q_28554079
{
    partial class FormTestZoom
    {
        /// <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.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.panel1 = new System.Windows.Forms.Panel();
            this.comboBox1 = new System.Windows.Forms.ComboBox();
            this.button1 = new System.Windows.Forms.Button();
            this.textBox1 = new System.Windows.Forms.TextBox();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.panel1.SuspendLayout();
            this.SuspendLayout();
            // 
            // pictureBox1
            // 
            this.pictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
            this.pictureBox1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.pictureBox1.Location = new System.Drawing.Point(0, 71);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(292, 202);
            this.pictureBox1.TabIndex = 0;
            this.pictureBox1.TabStop = false;
            this.pictureBox1.SizeModeChanged += new System.EventHandler(this.pictureBox1_SizeModeChanged);
            this.pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.pictureBox1_Paint);
            this.pictureBox1.Resize += new System.EventHandler(this.pictureBox1_Resize);
            // 
            // panel1
            // 
            this.panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
            this.panel1.Controls.Add(this.comboBox1);
            this.panel1.Controls.Add(this.button1);
            this.panel1.Controls.Add(this.textBox1);
            this.panel1.Dock = System.Windows.Forms.DockStyle.Top;
            this.panel1.Location = new System.Drawing.Point(0, 0);
            this.panel1.Name = "panel1";
            this.panel1.Size = new System.Drawing.Size(292, 71);
            this.panel1.TabIndex = 1;
            // 
            // comboBox1
            // 
            this.comboBox1.FormattingEnabled = true;
            this.comboBox1.Location = new System.Drawing.Point(10, 38);
            this.comboBox1.Name = "comboBox1";
            this.comboBox1.Size = new System.Drawing.Size(121, 21);
            this.comboBox1.TabIndex = 2;
            this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
            // 
            // button1
            // 
            this.button1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
            this.button1.Enabled = false;
            this.button1.Location = new System.Drawing.Point(203, 10);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 1;
            this.button1.Text = "Browse...";
            this.button1.UseVisualStyleBackColor = true;
            // 
            // textBox1
            // 
            this.textBox1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
            | System.Windows.Forms.AnchorStyles.Right)));
            this.textBox1.Enabled = false;
            this.textBox1.Location = new System.Drawing.Point(10, 12);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(187, 20);
            this.textBox1.TabIndex = 0;
            // 
            // FormTestZoom
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(292, 273);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.panel1);
            this.Name = "FormTestZoom";
            this.Text = "Q_28554079";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.panel1.ResumeLayout(false);
            this.panel1.PerformLayout();
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.PictureBox pictureBox1;
        private System.Windows.Forms.Panel panel1;
        private System.Windows.Forms.ComboBox comboBox1;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.TextBox textBox1;
    }
}

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townsma

ASKER

Hi Robert,

Thank looks exactly what I was looking for. I will try to pull the key parts, and embed it into my code, and see how it goes. Will get back to you asap.

Thanks

townsma

ASKER

Hi Robert,

You solution was just what I needed. I have a little problem with detecting mouse clicks over the shapes, but I simply divided the point.X and point.Y by the scaling factors, and it worked.

Thanks for such a clear and concise solution.

Best regards

Mark

townsma

ASKER

Great solution and example