我正在通过实际潜入它来学习C＃。我刚刚停了下来。我在下面有这个代码有一个菜单项，Acquire。当我选择它时，它会运行Acquire。但是我希望它在加载/启动应用程序后立即运行。
我在哪里做出必要的改变？
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;
}
}
答案 0 :(得分：9)
可能最好的地方是连接Form_Load事件处理程序，并在那里进行。
确定：
将您的代码从menuFileAcquire_Click移出到定义为private void Acquire的方法
从Acquire
menuFileAcquire_Click
使用Visual Studio，添加一个事件处理程序来处理表单的Loaded事件。
在该方法中（很可能称为MainForm_Loaded），也可以调用Acquire
这样，您的Acquire方法以及首次加载表单时触发的方法都会调用相同的功能。