.NET中捕获大小回车

 台式电脑键盘的大小回车在.NET中是个不好区分的事情，下面这个例子是我08年研究的捕获大小回车的例子，特记录。

 

其实，只要捕获消息的LParam，判断大小回车的键盘消息的参数Lparam值，就可以区别大小回车
小回车 0x1c0001 ==18612225
大回车 0x11c0001 == 1835009

所以这里提供两个测试项目的源代码，实现出来的捕获大小回车的效果都一样：

 

源代码一：

 

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace cswndproc { public partial class Form1 : Form { public Form1() { InitializeComponent(); } public new event KeyEventHandler KeyDown; public new event KeyPressEventHandler KeyPress; public new event KeyEventHandler KeyUp; private void Form1_Load(object sender, EventArgs e) { this.KeyDown += new KeyEventHandler(Form1_KeyDown); this.KeyPress += new KeyPressEventHandler(Form1_KeyPress); this.KeyUp += new KeyEventHandler(Form1_KeyUp); } void Form1_KeyPress(object sender, KeyPressEventArgs e) { throw new Exception("The method or operation is not implemented."); } void Form1_KeyDown(object sender, KeyEventArgs e) { throw new Exception("The method or operation is not implemented."); } void Form1_KeyUp(object sender, KeyEventArgs e) { throw new Exception("The method or operation is not implemented."); } const int WM_KEYDOWN = 0x100; const int WM_KEYUP = 0x101; const int WM_SYSKEYDOWN = 0x104; const int WM_SYSKEYUP = 0x105; const byte VK_RETURN = 0x0D; protected override void WndProc(ref Message m) { if (KeyDown != null && ((int)m.WParam == WM_KEYDOWN || (int)m.WParam == WM_SYSKEYDOWN)) { if (((int)m.WParam & VK_RETURN) != 0) { if ((int)m.WParam == 1835009) { MessageBox.Show("大回车按下了！"); } else if ((int)m.WParam == 18612225) { MessageBox.Show("小回车按下了！"); } } } base.WndProc(ref m); } protected override bool ProcessKeyMessage(ref Message m) { if (KeyDown != null && ((int)m.Msg == WM_KEYDOWN || (int)m.Msg == WM_SYSKEYDOWN)) { if (((int)m.WParam & VK_RETURN) != 0) { if ((int)m.LParam == 1835009) { MessageBox.Show("大回车按下了！"); } else if ((int)m.LParam == 18612225) { MessageBox.Show("小回车按下了！"); } } } int s = m.WParam.ToInt32(); if (m.Msg == 0x0102) { if ((s < 48) || (s > 57)) { //这里是需要屏蔽的字符（ASCII） MessageBox.Show("按下数字！"); return true; } } return base.ProcessKeyMessage(ref m); } } }

 

 

Designer文件源代码：

namespace cswndproc { partial class Form1 { /// <summary> /// 必需的设计器变量。 /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// 清理所有正在使用的资源。 /// </summary> /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows 窗体设计器生成的代码 /// <summary> /// 设计器支持所需的方法 - 不要 /// 使用代码编辑器修改此方法的内容。 /// </summary> private void InitializeComponent() { this.SuspendLayout(); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(292, 273); this.Name = "Form1"; this.Text = "Form1"; this.Load += new System.EventHandler(this.Form1_Load); this.ResumeLayout(false); } #endregion } }

 

 

 

源代码二：

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace WinFormReturn { public partial class Form1:Form,IMessageFilter { public Form1() { InitializeComponent(); //this.richTextBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(richTextBox1_KeyPress); //this.richTextBox1.KeyDown += new KeyEventHandler(richTextBox1_KeyDown); //this.richTextBox1.KeyUp += new KeyEventHandler(richTextBox1_KeyUp); } public new event KeyEventHandler KeyDown=null; public new event KeyPressEventHandler KeyPress = null; public new event KeyEventHandler KeyUp = null; private const int WM_KEYDOWN = 0x100; private bool boolstate; void richTextBox1_KeyUp(object sender, KeyEventArgs e) { richTextBox1.AppendText("KeyUp"); //e.Handled = false; //MessageBox.Show("KeyUp"); //throw new Exception("The method or operation is not implemented."); } void richTextBox1_KeyDown(object sender, KeyEventArgs e) { richTextBox1.AppendText("KeyDown"); //e.Handled = false ; // MessageBox.Show("KeyDown"); //throw new Exception("The method or operation is not implemented."); } // public class TestMessageFilter : IMessageFilter //{ public bool PreFilterMessage(ref System.Windows.Forms.Message m) { //if (m.Msg == 513)//允许接收的Windows消息 //{ // return false; //} //return true; if ((Keys)m.WParam.ToInt32() == Keys.Enter ) { string str=m.WParam.ToString()+m.LParam.ToString()+m.Msg.ToString(); if (m.LParam.ToInt32() == 0x11c0001 && m.Msg == 0x100 && richTextBox1.Focused) { richTextBox1.AppendText("按下的是小回车！"); //boolstate = true; return true ; //MessageBox.Show("按下的是小回车！"); //这里就是小回车 } else if (m.LParam.ToInt32() == 0x1c0001 && m.Msg == 0x100 && richTextBox1.Focused) { //MessageBox.Show("按下的是大回车！"); //if (!boolstate) //{ richTextBox1.AppendText("按下的是大回车！"); return true; //} return false; } } return false; } // } public void Form1_Load(object sender, EventArgs e) { Application.AddMessageFilter(this); } private void richTextBox1_KeyPress(object sender, KeyPressEventArgs e) { richTextBox1.AppendText("KeyPress"); // e.Handled = false; //MessageBox.Show("KeyPress"); } private void richTextBox1_TextChanged(object sender, EventArgs e) { } } }

 

Desinger文件源代码：

namespace WinFormReturn { partial class Form1 { /// <summary> /// 必需的设计器变量。 /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// 清理所有正在使用的资源。 /// </summary> /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows 窗体设计器生成的代码 /// <summary> /// 设计器支持所需的方法 - 不要 /// 使用代码编辑器修改此方法的内容。 /// </summary> private void InitializeComponent() { this.richTextBox1 = new System.Windows.Forms.RichTextBox(); this.SuspendLayout(); // // richTextBox1 // this.richTextBox1.Location = new System.Drawing.Point(16, 21); this.richTextBox1.Name = "richTextBox1"; this.richTextBox1.Size = new System.Drawing.Size(260, 195); this.richTextBox1.TabIndex = 0; this.richTextBox1.Text = ""; this.richTextBox1.TextChanged += new System.EventHandler(this.richTextBox1_TextChanged); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(292, 273); this.Controls.Add(this.richTextBox1); this.Name = "Form1"; this.Text = "Form1"; this.Load += new System.EventHandler(this.Form1_Load); this.ResumeLayout(false); } #endregion private System.Windows.Forms.RichTextBox richTextBox1; } }