关于图形处理的问题。（有源代码）

有这么一段代码
using System; 
using System.ComponentModel; 
using System.Drawing; 
using System.Windows.Forms; namespace PicsTransform 
{ 
   /// <summary> 
   /// 图像变换程序的主窗体，接受其子窗体的设置信息。 
   /// </summary> 
   public class MainForm : Form 
   { 
      private MainMenu mainMenu; 
      private MenuItem File; 
      private MenuItem OpenPics; 
      private MenuItem Transform; 
      private MenuItem x_Transform; 
      private PictureBox pictureBox; 
      private OpenFileDialog openFileDialog; 
      private MenuItem SizeChange; 
      private MenuItem PicsCircumrotate; 
      /// <summary> 
      /// 必需的设计器变量。 
      /// </summary> 
      private Container components = null;       public MainForm() 
      {          InitializeComponent();       }       protected override void Dispose( bool disposing ) 
      { 
         if( disposing ) 
         { 
            if (components != null)  
            { 
               components.Dispose(); 
            } 
         } 
         base.Dispose( disposing ); 
      }       #region Windows 窗体设计器生成的代码       private void InitializeComponent() 
      { 
         this.mainMenu = new MainMenu(); 
         this.File = new MenuItem(); 
         this.OpenPics = new MenuItem(); 
         this.Transform = new MenuItem(); 
         this.x_Transform = new MenuItem(); 
         this.SizeChange = new MenuItem(); 
         this.pictureBox = new PictureBox(); 
         this.openFileDialog = new OpenFileDialog(); 
         this.PicsCircumrotate = new MenuItem(); 
         this.SuspendLayout();          this.mainMenu.MenuItems.AddRange(new MenuItem[] { 
                                                                this.File, 
                                                                this.Transform}); 
 
         this.File.Index = 0; 
         this.File.MenuItems.AddRange(new MenuItem[] { 
                                                             this.OpenPics}); 
         this.File.Text = "文件";          this.OpenPics.Index = 0; 
         this.OpenPics.Text = "打开"; 
         this.OpenPics.Click += new EventHandler(this.OpenPics_Click); 
 
         this.Transform.Index = 1; 
         this.Transform.MenuItems.AddRange(new MenuItem[] { 
                                                                 this.x_Transform, 
                                                                 this.SizeChange, 
                                                                 this.PicsCircumrotate}); 
         this.Transform.Text = "图像变换"; 
 
         this.x_Transform.Index = 0; 
         this.x_Transform.Text = "图像平移"; 
         this.x_Transform.Click += new EventHandler(this.x_Transform_Click);          this.SizeChange.Index = 1; 
         this.SizeChange.Text = "图像缩放"; 
         this.SizeChange.Click += new EventHandler(this.SizeChange_Click); 
 
         this.pictureBox.Location = new Point(0, 0); 
         this.pictureBox.Name = "pictureBox"; 
         this.pictureBox.Size = new Size(584, 374); 
         this.pictureBox.SizeMode = PictureBoxSizeMode.AutoSize; 
         this.pictureBox.TabIndex = 0; 
         this.pictureBox.TabStop = false; 
  
         this.PicsCircumrotate.Index = 2; 
         this.PicsCircumrotate.Text = "图像旋转"; 
         this.PicsCircumrotate.Click += new EventHandler(this.PicsCircumrotate_Click); 
 
         this.AutoScaleBaseSize = new Size(6, 14); 
         this.AutoScroll = true; 
         this.ClientSize = new Size(584, 374); 
         this.Controls.Add(this.pictureBox); 
         this.Menu = this.mainMenu; 
         this.Name = "MainForm"; 
         this.Text = "图像变换"; 
         this.ResumeLayout(false);       } 
      #endregion       /// <summary> 
      /// 应用程序的主入口点。 
      /// </summary> 
      [STAThread] 
      static void Main()  
      { 
         Application.Run(new MainForm()); 
      } 
/// <summary> 
/// 打开一个图像文件（在此不是显式存储为数组） 
/// </summary> 
      Bitmap bmp; 
      private void OpenPics_Click(object sender, EventArgs e) 
      { 
         if (this.openFileDialog.ShowDialog()==DialogResult.OK) 
         { 
                         
            bmp=new Bitmap(this.openFileDialog.FileName); 
                         
            this.pictureBox.Image=bmp;          
             
         } 
      } 
/// <summary> 
/// 图像平面移动处理事件 
/// </summary> 
      float x=0,y=0; 
      private void x_Transform_Click(object sender, EventArgs e) 
      { 
         Getx_y answindow = new Getx_y(); 
         if(answindow.ShowDialog(this)==DialogResult.OK) //接受可变数值 
         { 
            x += (float)Double.Parse(answindow.textBox_x.Text); 
            y += (float)Double.Parse(answindow.textBox_y.Text); 
            //We would apply  
         } 
         answindow.Dispose(); 
         Bitmap final = new Bitmap(bmp.Width+(int)x,bmp.Height+(int)y ,pictureBox.CreateGraphics());//对图像数组进行扩充 
         Graphics g = Graphics.FromImage(final); 
         Point poi =new  Point(0,0); 
         Size siz = new Size(bmp.Width,bmp.Height); 
         Rectangle r = new Rectangle(poi,siz); 
         r = new Rectangle(poi,siz); 
         g.TranslateTransform(x,y);//对增广数组进行平移 
         g.DrawImage(bmp,r); 
         this.pictureBox.Image = final; 
      } 
/// <summary> 
/// 图像缩放处理事件 
/// </summary> 
      float changesize_x = 0,changesize_y=0;//缩放方向参数 
      private void SizeChange_Click(object sender, EventArgs e) 
      { 
         SizeChange answindow = new SizeChange(); 
         if(answindow.ShowDialog(this)==DialogResult.OK) 
         { 
            changesize_x += (float)Double.Parse(answindow.x_Size.Text); 
            changesize_y += (float)Double.Parse(answindow.y_Size.Text); 
            //We would apply  
         } 
         answindow.Dispose(); 
         float bmp_x = (float)bmp.Width*changesize_x; 
         float bmp_y = (float)bmp.Height*changesize_y; 
         Bitmap final = new Bitmap((int)bmp_x,(int)bmp_y ,pictureBox.CreateGraphics());//扩充图像原来的数组 
         Graphics g = Graphics.FromImage(final); 
         Point poi =new  Point(0,0); 
         Size siz = new Size(bmp.Width,bmp.Height); 
         this.Text=bmp.Width.ToString(); 
         Rectangle r = new Rectangle(poi,siz); 
         this.Text=siz.Height.ToString();          r = new Rectangle(poi,siz); 
         g.ScaleTransform(changesize_x,changesize_y);//进行缩放重绘 
         g.DrawImage(bmp,r); 
         this.pictureBox.Image = final; 
      } 
/// <summary> 
/// 图象旋转处理事件 
/// </summary> 
      float rotatearc = 0;//选择顺时针旋转角度（最好为0-90度，选择其他角度会有图像越界） 
      private void PicsCircumrotate_Click(object sender, EventArgs e) 
      { 
         Circumrotate answindow = new Circumrotate(); 
         if(answindow.ShowDialog(this)==DialogResult.OK) 
         { 
            rotatearc += (float)Double.Parse(answindow.arc.Text); 
         } 
         answindow.Dispose(); 
        
      }    } 
} 我运行了，但总提示Getx_y ，SizeChange ，Circumrotate 出错，找不到。 是怎么回事呢。望高手指点