Eliminar la barra de título en Windows Forms

¿Cómo puedo eliminar el borde azul que está en la parte superior del formulario de ventana? (No sé el nombre exactamente).

Puede establecer la propiedad FormBorderStyleen none en el diseñador o en el código:

this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;

si Blue Border thats on top of the Window Formse refiere a la barra de título , establezca la ControlBoxpropiedad Forms en falsey la Textpropiedad en una cadena vacía ("").

aquí hay un fragmento:

this.ControlBox = false;
this.Text = String.Empty;

También agregue este fragmento de código a su formulario para permitir que aún se pueda arrastrar.

Simplemente agréguelo justo antes del constructor (el método que llama a InitializeComponent ()

private const int WM_NCHITTEST = 0x84;
private const int HTCLIENT = 0x1;
private const int HTCAPTION = 0x2;

///
/// Handling the window messages
///
protected override void WndProc(ref Message message)
{
    base.WndProc(ref message);

    if (message.Msg == WM_NCHITTEST && (int)message.Result == HTCLIENT)
        message.Result = (IntPtr)HTCAPTION;
}

Ese código es de: https://jachman.wordpress.com/2006/06/08/enhanced-drag-and-move-winforms-without-having-a-titlebar/

Ahora, para deshacerse de la barra de título pero aún tener un borde, combine el código de la otra respuesta:

this.ControlBox = falso;

this.Text = String.Empty;

con esta línea:

this.FormBorderStyle = FormBorderStyle.FixedSingle;

Coloque esas 3 líneas de código en el evento OnLoad del formulario y debería tener un buen formulario 'flotante' que se pueda arrastrar con un borde delgado (use FormBorderStyle.None si no desea ningún borde).

 Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None

Conjunto FormsBorderStyledel formulario a None.

Si lo hace, depende de usted cómo implementar la funcionalidad de arrastrar y cerrar de la ventana.

Estoy compartiendo mi código. form1.cs: -

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace BorderExp
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;

    }

    private void ExitClick(object sender, EventArgs e)
    {
        Application.Exit();
    }

    private void MaxClick(object sender, EventArgs e)
    {
        if (WindowState ==FormWindowState.Normal)
        {
            this.WindowState = FormWindowState.Maximized;
        }
        else
        {
            this.WindowState = FormWindowState.Normal;
        }
    }

    private void MinClick(object sender, EventArgs e)
    {
        this.WindowState = FormWindowState.Minimized;
       }
    }
    }

Ahora, el diseñador: -

namespace BorderExp
 {
   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.button1 = new System.Windows.Forms.Button();
        this.button2 = new System.Windows.Forms.Button();
        this.button3 = new System.Windows.Forms.Button();
        this.SuspendLayout();
        // 
        // button1
        // 
        this.button1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
        this.button1.BackColor = System.Drawing.SystemColors.ButtonFace;
        this.button1.BackgroundImage = global::BorderExp.Properties.Resources.blank_1_;
        this.button1.FlatAppearance.BorderSize = 0;
        this.button1.FlatAppearance.MouseOverBackColor = System.Drawing.Color.FromArgb(((int)(((byte)(224)))), ((int)(((byte)(224)))), ((int)(((byte)(224)))));
        this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
        this.button1.Location = new System.Drawing.Point(376, 1);
        this.button1.Name = "button1";
        this.button1.Size = new System.Drawing.Size(27, 26);
        this.button1.TabIndex = 0;
        this.button1.Text = "X";
        this.button1.UseVisualStyleBackColor = false;
        this.button1.Click += new System.EventHandler(this.ExitClick);
        // 
        // button2
        // 
        this.button2.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
        this.button2.BackColor = System.Drawing.SystemColors.ButtonFace;
        this.button2.BackgroundImage = global::BorderExp.Properties.Resources.blank_1_;
        this.button2.FlatAppearance.BorderSize = 0;
        this.button2.FlatAppearance.MouseOverBackColor = System.Drawing.Color.FromArgb(((int)(((byte)(224)))), ((int)(((byte)(224)))), ((int)(((byte)(224)))));
        this.button2.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
        this.button2.Location = new System.Drawing.Point(343, 1);
        this.button2.Name = "button2";
        this.button2.Size = new System.Drawing.Size(27, 26);
        this.button2.TabIndex = 1;
        this.button2.Text = "[]";
        this.button2.UseVisualStyleBackColor = false;
        this.button2.Click += new System.EventHandler(this.MaxClick);
        // 
        // button3
        // 
        this.button3.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
        this.button3.BackColor = System.Drawing.SystemColors.ButtonFace;
        this.button3.BackgroundImage = global::BorderExp.Properties.Resources.blank_1_;
        this.button3.FlatAppearance.BorderSize = 0;
        this.button3.FlatAppearance.MouseOverBackColor = System.Drawing.Color.FromArgb(((int)(((byte)(224)))), ((int)(((byte)(224)))), ((int)(((byte)(224)))));
        this.button3.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
        this.button3.Location = new System.Drawing.Point(310, 1);
        this.button3.Name = "button3";
        this.button3.Size = new System.Drawing.Size(27, 26);
        this.button3.TabIndex = 2;
        this.button3.Text = "___";
        this.button3.UseVisualStyleBackColor = false;
        this.button3.Click += new System.EventHandler(this.MinClick);
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.BackgroundImage = global::BorderExp.Properties.Resources.blank_1_;
        this.ClientSize = new System.Drawing.Size(403, 320);
        this.ControlBox = false;
        this.Controls.Add(this.button3);
        this.Controls.Add(this.button2);
        this.Controls.Add(this.button1);
        this.Name = "Form1";
        this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
        this.Text = "Form1";
        this.Load += new System.EventHandler(this.Form1_Load);
        this.ResumeLayout(false);

    }

    #endregion

    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.Button button2;
    private System.Windows.Forms.Button button3;
    }
   }

la captura de pantalla: - NoBorderForm