C＃代码理解和学习

Question

我正在通过深入学习C＃来学习C＃。我刚刚停下来。我有下面的代码，其中有一个菜单项，Acquire。它在我选择它时运行“获取”罚款。但是我希望它在应用程序加载/启动后立即运行获取。

我该在哪里做必要的更改？

using System; 
using System.Drawing; 
using System.Collections; 
using System.ComponentModel; 
using System.Windows.Forms; 
using System.Data; 
using System.IO; 
using System.Runtime.InteropServices; 

using WIALib; // namespace of imported WIA Scripting COM component 

namespace Wia 
{ 
    /// <summary> MainForm for this WIA sample </summary> 
    public class MainForm : System.Windows.Forms.Form 
    { 
     private System.Windows.Forms.MainMenu mainMenu; 
     private System.Windows.Forms.MenuItem menuTopFile; 
     private System.Windows.Forms.MenuItem menuFileAcquire; 
     private System.Windows.Forms.MenuItem menuFileSaveAs; 
     private System.Windows.Forms.MenuItem menuFileSep1; 
     private System.Windows.Forms.MenuItem menuFileExit; 
     private System.Windows.Forms.PictureBox pictureBox; 
     private IContainer components; 

     public MainForm() 
     { 
      // 
      // Required for Windows Form Designer support 
      // 

      InitializeComponent(); 

     } 

     /// <summary> 
     /// Clean up any resources being used. 
     /// </summary> 
     protected override void Dispose(bool disposing) 
     { 
      if(disposing) 
      { 
       DisposeImage(); 

       if (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.components = new System.ComponentModel.Container(); 
      System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(MainForm)); 
      this.mainMenu = new System.Windows.Forms.MainMenu(this.components); 
      this.menuTopFile = new System.Windows.Forms.MenuItem(); 
      this.menuFileAcquire = new System.Windows.Forms.MenuItem(); 
      this.menuFileSaveAs = new System.Windows.Forms.MenuItem(); 
      this.menuFileSep1 = new System.Windows.Forms.MenuItem(); 
      this.menuFileExit = new System.Windows.Forms.MenuItem(); 
      this.pictureBox = new System.Windows.Forms.PictureBox(); 
      ((System.ComponentModel.ISupportInitialize)(this.pictureBox)).BeginInit(); 
      this.SuspendLayout(); 
      // 
      // mainMenu 
      // 
      this.mainMenu.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] { 
      this.menuTopFile}); 
      // 
      // menuTopFile 
      // 
      this.menuTopFile.Index = 0; 
      this.menuTopFile.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] { 
      this.menuFileAcquire, 
      this.menuFileSaveAs, 
      this.menuFileSep1, 
      this.menuFileExit}); 
      this.menuTopFile.Text = "&File"; 
      // 
      // menuFileAcquire 
      // 
      this.menuFileAcquire.Index = 0; 
      this.menuFileAcquire.Text = "Acquire..."; 
      this.menuFileAcquire.Click += new System.EventHandler(this.menuFileAcquire_Click); 
      // 
      // menuFileSaveAs 
      // 
      this.menuFileSaveAs.Enabled = false; 
      this.menuFileSaveAs.Index = 1; 
      this.menuFileSaveAs.Text = "Save &As..."; 
      this.menuFileSaveAs.Click += new System.EventHandler(this.menuFileSaveAs_Click); 
      // 
      // menuFileSep1 
      // 
      this.menuFileSep1.Index = 2; 
      this.menuFileSep1.Text = "-"; 
      // 
      // menuFileExit 
      // 
      this.menuFileExit.Index = 3; 
      this.menuFileExit.Text = "E&xit"; 
      this.menuFileExit.Click += new System.EventHandler(this.menuFileExit_Click); 
      // 
      // pictureBox 
      // 
      this.pictureBox.Location = new System.Drawing.Point(8, 8); 
      this.pictureBox.Name = "pictureBox"; 
      this.pictureBox.Size = new System.Drawing.Size(488, 357); 
      this.pictureBox.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize; 
      this.pictureBox.TabIndex = 0; 
      this.pictureBox.TabStop = false; 
      // 
      // MainForm 
      // 
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); 
      this.AutoScroll = true; 
      this.BackColor = System.Drawing.SystemColors.Window; 
      this.ClientSize = new System.Drawing.Size(520, 377); 
      this.Controls.Add(this.pictureBox); 
      this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon"))); 
      this.Menu = this.mainMenu; 
      this.MinimumSize = new System.Drawing.Size(256, 256); 
      this.Name = "MainForm"; 
      this.Text = "Scanning Device"; 
      ((System.ComponentModel.ISupportInitialize)(this.pictureBox)).EndInit(); 
      this.ResumeLayout(false); 
      this.PerformLayout(); 

     } 
     #endregion 

     /// <summary> The main entry point for the application. </summary> 
     [STAThread] 
     static void Main() 
     { 
      Application.Run(new MainForm()); 
     } 

     private void menuFileExit_Click(object sender, System.EventArgs e) 
     { 
      Close(); 
     } 

     private void menuFileAcquire_Click(object sender, System.EventArgs e) 
     { 
      WiaClass  wiaManager = null;  // WIA manager COM object 
      CollectionClass wiaDevs  = null;  // WIA devices collection COM object 
      ItemClass  wiaRoot  = null;  // WIA root device COM object 
      CollectionClass wiaPics  = null;  // WIA collection COM object 
      ItemClass  wiaItem  = null;  // WIA image COM object 

      try { 
       wiaManager = new WiaClass();  // create COM instance of WIA manager 

       wiaDevs = wiaManager.Devices as CollectionClass;   // call Wia.Devices to get all devices 
       if((wiaDevs == null) || (wiaDevs.Count == 0)) 
       { 
        MessageBox.Show(this, "No WIA devices found!", "WIA", MessageBoxButtons.OK, MessageBoxIcon.Stop); 
        Application.Exit(); 
        return; 
       } 

       object selectUsingUI = System.Reflection.Missing.Value;   // = Nothing 
       wiaRoot = (ItemClass) wiaManager.Create(ref selectUsingUI); // let user select device 
       if(wiaRoot == null)           // nothing to do 
        return; 

       // this call shows the common WIA dialog to let the user select a picture: 
       wiaPics = wiaRoot.GetItemsFromUI(WiaFlag.SingleImage, WiaIntent.ImageTypeColor) as CollectionClass; 
       if(wiaPics == null) 
        return; 

       bool takeFirst = true;      // this sample uses only one single picture 
       foreach(object wiaObj in wiaPics)   // enumerate all the pictures the user selected 
       { 
        if(takeFirst) 
        { 
         DisposeImage();      // remove previous picture 
         wiaItem = (ItemClass) Marshal.CreateWrapperOfType(wiaObj, typeof(ItemClass)); 
         imageFileName = Path.GetTempFileName();    // create temporary file for image 
         Cursor.Current = Cursors.WaitCursor;    // could take some time 
         this.Refresh(); 
         wiaItem.Transfer(imageFileName, false);   // transfer picture to our temporary file 
         pictureBox.Image = Image.FromFile(imageFileName); // create Image instance from file 
         menuFileSaveAs.Enabled = true;      // enable "Save as" menu entry 
         takeFirst = false;         // first and only one done. 
        } 
        Marshal.ReleaseComObject(wiaObj);     // release enumerated COM object 
       } 
      } 
      catch(Exception ee) { 
       MessageBox.Show(this, "Acquire from WIA Imaging failed\r\n" + ee.Message, "WIA", MessageBoxButtons.OK, MessageBoxIcon.Stop); 
       Application.Exit(); 
      } 
      finally { 
       if(wiaItem != null) 
        Marshal.ReleaseComObject(wiaItem);  // release WIA image COM object 
       if(wiaPics != null) 
        Marshal.ReleaseComObject(wiaPics);  // release WIA collection COM object 
       if(wiaRoot != null) 
        Marshal.ReleaseComObject(wiaRoot);  // release WIA root device COM object 
       if(wiaDevs != null) 
        Marshal.ReleaseComObject(wiaDevs);  // release WIA devices collection COM object 
       if(wiaManager != null) 
        Marshal.ReleaseComObject(wiaManager);  // release WIA manager COM object 
       Cursor.Current = Cursors.Default;    // restore cursor 
      } 
     } 

      /// <summary> User selected menu entry to save image. </summary> 
     private void menuFileSaveAs_Click(object sender, System.EventArgs e) 
     { 
      if(pictureBox.Image == null)    // no bitmap exists 
       return; 

      SaveFileDialog sd = new SaveFileDialog(); 
      sd.Title = "Save Image As..."; 
      sd.FileName = "temp.bmp"; 
      sd.Filter = "Bitmap file (*.bmp)|*.bmp"; // bmp bitmap file format 
      if(sd.ShowDialog() != DialogResult.OK) 
       return; 

      pictureBox.Image.Save(sd.FileName);  // save to file 
     } 

     /// <summary> Remove image from screen, dispose object and delete the temporary file. </summary> 
     private void DisposeImage() 
     { 
      menuFileSaveAs.Enabled = false;    // disable "Save As" menu entry 
      Image oldImg = pictureBox.Image; 
      pictureBox.Image = null;     // empty picture box 
      if(oldImg != null) 
       oldImg.Dispose();      // dispose old image (free memory, unlock file) 

      if(imageFileName != null) {    // try to delete the temporary image file 
       try { 
        File.Delete(imageFileName); 
       } 
       catch(Exception) 
       { } 
      } 
     } 

     /// <summary> temporary image file. </summary> 
     private string imageFileName; 
    } 
} 

Answer 1

也许是最好的地方将是要连接一个事件处理程序，并做到这一点那里。

确定：

1. 从menuFileAcquire_Click

2. 使用Visual Studio将你的代码出menuFileAcquire_Click到定义为private void Acquire

3. 呼叫Acquire的方法，添加事件处理程序来处理表单的Loaded事件。

4. 在这一方法（最有可能称为MainForm_Loaded），也叫Acquire

这样，相同的功能是通过您的采集方法，以及该方法被称为既被触发时窗体首先加载。