Windows Forms 中控件的位置和大小在 Visual Studio Designer 和编程实例化之间有所不同

Question

when I create a Windows Forms Application using Visual Studio (Community 2019) and the Designer tool it appears that controls have not the correct sizes and positions. Eg positioning a TextBox at (100, 80) with size (100, 22) is actually not positioned at the desired location. Also the x-dimension of the size is actually 75 and not 100. If I instantiate a similar TextBox programmatically with the same values (just shifted in y-position) it is placed more to the right and it is bigger in size compared to the other one, but this time with the correct values.

See the attached pictures.

I have created a small test application in order to demonstrate this.

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsTest
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

Form1.Designer.cs

namespace WindowsFormsTest
{
    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.textBox1 = new System.Windows.Forms.TextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(100, 80);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(100, 22);
            this.textBox1.TabIndex = 0;
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(12, 9);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(46, 17);
            this.label1.TabIndex = 1;
            this.label1.Text = "label1";
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 450);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.textBox1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.Label label1;
    }
}

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 WindowsFormsTest
{
    public partial class Form1 : Form
    {
        private TextBox textBox2;

        public Form1()
        {
            InitializeComponent();
            TestBox();
            this.MouseMove += new MouseEventHandler(MouseMoved);
        }


        private void TestBox()
        {
            textBox2 = new TextBox() {
                Location = new System.Drawing.Point(100, 104),
                Name = "textBox2",
                Size = new System.Drawing.Size(100, 22),
                TabIndex = 1
            };

            this.Controls.Add(textBox2);
        }

        private void MouseMoved(object sender, MouseEventArgs evt)
        {
            label1.Text = "X = " + evt.X.ToString() + ", Y = " + evt.Y.ToString();
        }
    }
}

What am I missing here? How can I achieve that the control via designer has the desired size and position (like the second TextBox) or vice versa?

Thanks in advance for any help!

Answer 1

I had this exact problem a few months back. It's your monitor (or technically you're display resolution and scaling). You've got a high DPI monitor I'm guessing. You can see in VS there is a little notification about scaling - the VS windows forms designer doesn't seem to handle scaling well.

I fixed this by firstly discarding any changes I had made to my form first and closing VS. Then changed my monitor resolution back to standard HD (because without scaling my 4k monitor made things too small - you could just try standard 100% scaling) and then opened my VS and made my changes and all worked fine.

This answer here https://stackoverflow.com/a/12406133/6915929 seems to be describing a way of setting things up on the form to handle DPI changes, but I haven't tried that myself