在C#中，可以使用Windows Forms或WPF來實現固定布局的響應式設計。這里分別為兩者提供一個簡單的示例。

1. Windows Forms:

首先，需要安裝ResponsiveWindowsForms項目（https://github.com/MahApps/ResponsiveWindowsForms）。通過NuGet包管理器安裝ResponsiveWindowsForms庫。

然后，創建一個新的Windows Forms項目，并在Form1上添加控件。

using System;
using System.Drawing;
using System.Windows.Forms;
using ResponsiveWindowsForms;

namespace WindowsFormsResponsiveLayout
{
    public partial class Form1 : Form
    {
        private readonly ResponsiveForm responsiveForm;

        public Form1()
        {
            InitializeComponent();

            // 初始化ResponsiveForm
            responsiveForm = new ResponsiveForm(this);

            // 添加響應式布局
            responsiveForm.AddRange(new[]
            {
                new ResponsiveRow(new[]
                {
                    new ResponsiveControl(label1, new RectangleF(0, 0, 50, 100), ResponsiveAlignment.Center),
                    new ResponsiveControl(textBox1, new RectangleF(50, 0, 50, 100), ResponsiveAlignment.Center)
                }),
                new ResponsiveRow(new[]
                {
                    new ResponsiveControl(button1, new RectangleF(0, 0, 100, 100), ResponsiveAlignment.Center)
                })
            });
        }

        protected override void OnSizeChanged(EventArgs e)
        {
            base.OnSizeChanged(e);

            // 更新響應式布局
            responsiveForm.UpdateLayout();
        }
    }
}

2. WPF:

在WPF中，可以使用Grid和ColumnDefinition來實現響應式布局。創建一個新的WPF項目，并在MainWindow上添加控件。

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfResponsiveLayout"
        mc:Ignorable="d"
        Title="MainWindow" Height="150" Width="300">
    <Grid>
        <Grid.ColumnDefinitions>
           <ColumnDefinition Width="Auto"/>
           <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

       <Label Grid.Column="0" Grid.Row="0" Content="Label:" VerticalAlignment="Center"/>
       <TextBox Grid.Column="1" Grid.Row="0" VerticalAlignment="Center"/>
       <Button Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" Content="Button" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>
</Window>

這樣，在調整窗口大小時，布局會自動適應屏幕尺寸。