Get Async Key State
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
public class Form1 : Form
{
[DllImport("User32.dll")]
private static extern short GetAsyncKeyState( System.Windows.Forms.Keys vKey);
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Label lbl;
private System.Windows.Forms.Button cmdAsyncState;
public Form1() {
InitializeComponent();
}
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = true;
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
lbl.Text = "Key Down: " + e.KeyValue.ToString();
lbl.Text += "\nKey Code: " + e.KeyCode.ToString();
lbl.Text += "\nKey Data: " + e.KeyData.ToString();
if ((e.Modifiers & Keys.Shift) == Keys.Shift)
{
lbl.Text += "\n" + "Shift was held down.";
}
if ((e.Modifiers & Keys.Control) == Keys.Control)
{
lbl.Text += "\n" + "Control was held down.";
}
if (e.Alt)
{
lbl.Text += "\n" + "Alt was held down.";
}
}
private void cmdAsyncState_Click(object sender, EventArgs e)
{
int state = Convert.ToInt32(GetAsyncKeyState(Keys.A).ToString());
switch (state)
{
case 0:
lbl.Text = "A has not been pressed since the last call.";
break;
case 1:
lbl.Text = "A is not currently pressed, but has been pressed since the last call.";
break;
case -32767:
lbl.Text = "A is currently pressed.";
break;
}
}
private void InitializeComponent()
{
this.textBox1 = new System.Windows.Forms.TextBox();
this.lbl = new System.Windows.Forms.Label();
this.cmdAsyncState = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(36, 36);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(205, 21);
this.textBox1.TabIndex = 0;
this.textBox1.Text = "<Text will never appear here>";
//
// lbl
//
this.lbl.AutoSize = true;
this.lbl.Location = new System.Drawing.Point(35, 77);
this.lbl.Name = "lbl";
this.lbl.Size = new System.Drawing.Size(0, 0);
this.lbl.TabIndex = 1;
//
// cmdAsyncState
//
this.cmdAsyncState.Location = new System.Drawing.Point(36, 202);
this.cmdAsyncState.Name = "cmdAsyncState";
this.cmdAsyncState.Size = new System.Drawing.Size(141, 24);
this.cmdAsyncState.TabIndex = 2;
this.cmdAsyncState.Text = "GetAsyncState() for \"A\"";
this.cmdAsyncState.Click += new System.EventHandler(this.cmdAsyncState_Click);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.cmdAsyncState);
this.Controls.Add(this.lbl);
this.Controls.Add(this.textBox1);
this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.KeyPreview = true;
this.Name = "Form1";
this.Text = "KeyTest";
this.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.Form1_KeyPress);
this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.Form1_KeyDown);
this.ResumeLayout(false);
this.PerformLayout();
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
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