How to dynamically resize a textbox in C#

Question

I am new to C# user interface. I have created a window as shown in the first image. But if the user drag the window and make it bigger, I would like for it to make each

Answer 1

You can do it in designer.

Use the TableLayoutPanel, and set its Anchor property to Top,Bottom,Left,Right and for each RichtTextBox inside the cells set Dock to Fill.

this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
        this.button1 = new System.Windows.Forms.Button();
        this.richTextBox1 = new System.Windows.Forms.RichTextBox();
        this.richTextBox2 = new System.Windows.Forms.RichTextBox();
        this.richTextBox3 = new System.Windows.Forms.RichTextBox();
        this.richTextBox4 = new System.Windows.Forms.RichTextBox();
        this.tableLayoutPanel1.SuspendLayout();
        this.SuspendLayout();
        // 
        // tableLayoutPanel1
        // 
        this.tableLayoutPanel1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
        | System.Windows.Forms.AnchorStyles.Left) 
        | System.Windows.Forms.AnchorStyles.Right)));
        this.tableLayoutPanel1.ColumnCount = 2;
        this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F)); //this line sets the Column percentage
        this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
        this.tableLayoutPanel1.Controls.Add(this.richTextBox4, 1, 1);
        this.tableLayoutPanel1.Controls.Add(this.richTextBox3, 0, 1);
        this.tableLayoutPanel1.Controls.Add(this.richTextBox2, 1, 0);
        this.tableLayoutPanel1.Controls.Add(this.richTextBox1, 0, 0);
        this.tableLayoutPanel1.Location = new System.Drawing.Point(24, 80);
        this.tableLayoutPanel1.Name = "tableLayoutPanel1";
        this.tableLayoutPanel1.RowCount = 2;
        this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 50F));
        this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 50F));
        this.tableLayoutPanel1.Size = new System.Drawing.Size(861, 567);
        this.tableLayoutPanel1.TabIndex = 0;
        // 
        // button1
        // 
        this.button1.Location = new System.Drawing.Point(24, 27);
        this.button1.Name = "button1";
        this.button1.Size = new System.Drawing.Size(137, 47);
        this.button1.TabIndex = 0;
        this.button1.Text = "button1";
        this.button1.UseVisualStyleBackColor = true;
        this.button1.Click += new System.EventHandler(this.button1_Click);
        // 
        // richTextBox1
        // 
        this.richTextBox1.Dock = System.Windows.Forms.DockStyle.Fill;
        this.richTextBox1.Location = new System.Drawing.Point(3, 3);
        this.richTextBox1.Name = "richTextBox1";
        this.richTextBox1.Size = new System.Drawing.Size(424, 277);
        this.richTextBox1.TabIndex = 0;
        this.richTextBox1.Text = "";
        // 
        // richTextBox2
        // 
        this.richTextBox2.Dock = System.Windows.Forms.DockStyle.Fill;
        this.richTextBox2.Location = new System.Drawing.Point(433, 3);
        this.richTextBox2.Name = "richTextBox2";
        this.richTextBox2.Size = new System.Drawing.Size(425, 277);
        this.richTextBox2.TabIndex = 1;
        this.richTextBox2.Text = "";
        // 
        // richTextBox3
        // 
        this.richTextBox3.Dock = System.Windows.Forms.DockStyle.Fill;
        this.richTextBox3.Location = new System.Drawing.Point(3, 286);
        this.richTextBox3.Name = "richTextBox3";
        this.richTextBox3.Size = new System.Drawing.Size(424, 278);
        this.richTextBox3.TabIndex = 2;
        this.richTextBox3.Text = "";
        // 
        // richTextBox4
        // 
        this.richTextBox4.Dock = System.Windows.Forms.DockStyle.Fill;
        this.richTextBox4.Location = new System.Drawing.Point(433, 286);
        this.richTextBox4.Name = "richTextBox4";
        this.richTextBox4.Size = new System.Drawing.Size(425, 278);
        this.richTextBox4.TabIndex = 3;
        this.richTextBox4.Text = "";
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(12F, 25F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(922, 659);
        this.Controls.Add(this.button1);
        this.Controls.Add(this.tableLayoutPanel1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.tableLayoutPanel1.ResumeLayout(false);
        this.ResumeLayout(false);