动态获取当前屏幕中光标所在位置的颜色

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/// 程序：屏幕取色

/// 功能：动态获取当前屏幕中光标所在位置的颜色

///作者：黎波

///网名：upto(阿球)

/// 邮箱：[e-mail]

/// 日期：<chsdate year="2004" month="3" day="31" islunardate="False" isrocdate="False" w:st="on"></chsdate>2004年3月31日

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using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

using System.Drawing.Imaging;

using System.Runtime.InteropServices;

namespace LiBo.ColorPicker

{

/// <summary>

/// Form1 的摘要说明。

/// </summary>

public class Form1 : System.Windows.Forms.Form

{

// 桌面工作区的尺寸

Size workingArea;

// Form 的初始位置和在左下角，右下角的位置

Point formLoc, ptLeftBottom, ptRightBottom;

private System.Windows.Forms.Label lblColor;

private System.Windows.Forms.TextBox txtArgb;

private System.Windows.Forms.Timer tmr;

private System.Windows.Forms.ToolTip tip;

private System.ComponentModel.IContainer components;

public Form1()

{

InitializeComponent();

this.FormBorderStyle = FormBorderStyle.FixedToolWindow;

this.StartPosition = FormStartPosition.CenterScreen;

Rectangle rect = SystemInformation.WorkingArea;

workingArea = new Size(rect.Width, rect.Height);

ptLeftBottom = new Point(0, workingArea.Height - this.Height);

ptRightBottom = new Point(workingArea.Width - this.Width,

workingArea.Height - this.Height);

String tipMsg = "在窗体空白处双击鼠标左键开始取色，按ESC键确定颜色";

tip.SetToolTip(this, tipMsg);

tip.SetToolTip(lblColor, tipMsg);

tip.SetToolTip(txtArgb, tipMsg);

}

/// <summary>

/// 清理所有正在使用的资源。

/// </summary>

protected override void Dispose( bool disposing )

{

if( disposing )

{

if (components != null)

{

components.Dispose();

}

}

base.Dispose( disposing );

}

#region Windows Form Designer generated code

/// <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.components = new System.ComponentModel.Container();

this.lblColor = new System.Windows.Forms.Label();

this.tmr = new System.Windows.Forms.Timer(this.components);

this.txtArgb = new System.Windows.Forms.TextBox();

this.tip = new System.Windows.Forms.ToolTip(this.components);

this.SuspendLayout();

//

// lblColor

//

this.lblColor.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;

this.lblColor.Location = new System.Drawing.Point(8, 8);

this.lblColor.Name = "lblColor";

this.lblColor.TabIndex = 0;

//

// tmr

//

this.tmr.Tick += new System.EventHandler(this.tmr_Tick);

//

// txtArgb

//

this.txtArgb.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;

this.txtArgb.Font = new System.Drawing.Font("Arial", 10.5F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));

this.txtArgb.Location = new System.Drawing.Point(8, 40);

this.txtArgb.Name = "txtArgb";

this.txtArgb.TabIndex = 1;

this.txtArgb.Text = "";

this.txtArgb.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.txtArgb_KeyPress);

//

// Form1

//

this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);

this.ClientSize = new System.Drawing.Size(115, 70);

this.Controls.Add(this.txtArgb);

this.Controls.Add(this.lblColor);

this.Name = "Form1";

this.Text = "屏幕取色(upto)";

this.DoubleClick += new System.EventHandler(this.Form1_DoubleClick);

this.MouseEnter += new System.EventHandler(this.Form1_MouseEnter);

this.ResumeLayout(false);

}

#endregion

/// <summary>

/// 应用程序的主入口点。

/// </summary>

[STAThread]

static void Main()

{

Application.Run(new Form1());

}

[ DllImport ( "gdi32.dll" ) ]

private static extern bool BitBlt (

IntPtr hdcDest, // 目标设备的句柄

int nXDest, // 目标对象的左上角的X坐标

int nYDest, // 目标对象的左上角的X坐标

int nWidth, // 目标对象的矩形的宽度

int nHeight, // 目标对象的矩形的长度

IntPtr hdcSrc, // 源设备的句柄

int nXSrc, // 源对象的左上角的X坐标

int nYSrc, // 源对象的左上角的X坐标

int dwRop // 光栅的操作值

);

[ DllImport ( "gdi32.dll" ) ]

private static extern IntPtr CreateDC (

string lpszDriver, // 驱动名称

string lpszDevice, // 设备名称

string lpszOutput, // 无用，可以设定位"NULL"

IntPtr lpInitData // 任意的打印机数据

);

private void Form1_DoubleClick(object sender, EventArgs e)

{

formLoc = this.Location;

this.Location = ptRightBottom;

this.TopMost = true;

tmr.Enabled = true;

}

private void tmr_Tick(object sender, EventArgs e)

{

// 创建显示器的DC

IntPtr hdlDisplay = CreateDC("DISPLAY", null, null, IntPtr.Zero);

// 从指定设备的句柄创建新的 Graphics 对象

Graphics gfxDisplay = Graphics.FromHdc(hdlDisplay);

// 创建只有一个象素大小的 Bitmap 对象

Bitmap bmp = new Bitmap(1, 1, gfxDisplay);

// 从指定 Image 对象创建新的 Graphics 对象

Graphics gfxBmp = Graphics.FromImage(bmp);

// 获得屏幕的句柄

IntPtr hdlScreen = gfxDisplay.GetHdc();

// 获得位图的句柄

IntPtr hdlBmp = gfxBmp.GetHdc();

// 把当前屏幕中鼠标指针所在位置的一个象素拷贝到位图中

BitBlt(hdlBmp, 0, 0, 1, 1, hdlScreen, MousePosition.X, MousePosition.Y, 13369376);

// 释放屏幕句柄

gfxDisplay.ReleaseHdc(hdlScreen);

// 释放位图句柄

gfxBmp.ReleaseHdc(hdlBmp);

lblColor.BackColor = bmp.GetPixel(0, 0); // 获取像素的颜色

txtArgb.Text = "0x" + lblColor.BackColor.ToArgb().ToString("x").ToUpper();

gfxDisplay.Dispose();
gfxBmp.Dispose();

bmp.Dispose(); // 释放 bmp 所使用的资源

}

private void txtArgb_KeyPress(object sender, KeyPressEventArgs e)

{

// 当按下ESC键时，确定所取的颜色ARGB值

// 注意：只有当窗体处于激活状态时才有效

if (e.KeyChar == (char)Keys.Escape)

{

tmr.Enabled = false;

this.Location = formLoc;

this.TopMost = false;

txtArgb.SelectAll();

}

}

private void Form1_MouseEnter(object sender, EventArgs e)

{

if (this.Location == ptLeftBottom) //窗体在左下角

{

this.Location = ptRightBottom;

}

else if (this.Location == ptRightBottom) // 窗体在右下角

{

this.Location = ptLeftBottom;

}

}

}

}