用C#实现的小截屏软件

第一次写博客，文笔较差，将就看吧

日常生活中会经常使用到截屏功能，使用最多的无非就是Windows自带的截图工具、QQ截图和PrintScreen键，但要达到截图到word或保存到文件，需要鼠标选择多次。比如我们想截图并将图插入到Word中，不需要保存图片，我们希望直接点击截图按钮，选择截图区域，Ctrl+V简单三步就行了（感觉说了好多废话），切入正题。

1.基本功能

选择屏幕区域后提醒你保存所截的图片，或直接将所截图片放到剪切板里（以便用Ctrl+V粘贴）。

2.界面设计

界面很简单，无非就是可实现以上功能的两个按钮和其他文字，见图：

界面的属性需要注意几个问题：

1）窗口设为固定大小，并禁用窗口最大化（因为我们不希望窗口大小会变）

2）窗口最好设为顶置

3）把两个文字label和两个按钮都放到一个panel里，以便于后面程序对控件属性的操作

4）那么大的按钮，最好改变一下它的样式，还可以设置背景为gif动图

3.功能实现

那么关键问题来了，怎么截图呢？见下图

原理其实很简单，就是在点击按钮后，窗口变为全屏覆盖在屏幕最上方，并变为半透明，使你能看到窗口下面的屏幕内容，然后拖动鼠标（此时其实是在软件的主窗口上拖动，这样就方便程序捕捉鼠标坐标了），根据坐标在屏幕上绘制选框，接着松开鼠标后，根据鼠标落下和松开的坐标，截取屏幕，最后保存或复制到剪切板。

4.敲代码吧

  1: using System;

  2: using System.Windows.Forms;

  3: using System.Drawing;//绘图要用

  4: using System.Threading;//延时函数要用

  5:

  6: namespace 截屏

  7: {

  8:     public partial class Form1 : Form

  9:     {

 10:         bool mouseDown = false, havePainted = false;

 11:         Point start, end;

 12:         Point start1, end1;

 13:         Size size = new Size(0, 0);

 14:         bool saveFile = true;

 15:         public Form1()

 16:         {

 17:             InitializeComponent();

 18:         }

 19:

 20:         private void button1_Click(object sender, EventArgs e)

 21:         {

 22:             ReadyToCaptrue();

 23:             saveFile = true;

 24:         }

 25:

 26:         private void Form1_MouseDown(object sender, MouseEventArgs e)

 27:         {

 28:             start = GetRealPoint(e.Location);

 29:             mouseDown = true;

 30:         }

 31:

 32:         private void Form1_MouseUp(object sender, MouseEventArgs e)

 33:         {

 34:             if (size.Width != 0 && size.Height != 0)

 35:             {

 36:                 ControlPaint.DrawReversibleFrame(new Rectangle(start1, size), Color.Transparent, FrameStyle.Dashed);

 37:                 havePainted = false;

 38:             }

 39:             end = GetRealPoint(e.Location);

 40:             if (start.X > end.X)

 41:             {

 42:                 int temp = end.X;

 43:                 end.X = start.X;

 44:                 start.X = temp;

 45:             }

 46:

 47:             if (start.Y > end.Y)

 48:             {

 49:                 int temp = end.Y;

 50:                 end.Y = start.Y;

 51:                 start.Y = temp;

 52:             }

 53:             this.Opacity = 0.0;

 54:             Thread.Sleep(200);

 55:             if (end.X - start.X > 0 && end.Y - start.Y > 0)

 56:             {

 57:                 Bitmap bit = new Bitmap(end.X - start.X, end.Y - start.Y);

 58:                 Graphics g = Graphics.FromImage(bit);

 59:                 g.CopyFromScreen(start, new Point(0, 0), bit.Size);

 60:                 if (saveFile)

 61:                 {

 62:                     SaveFileDialog saveFileDialog = new SaveFileDialog();

 63:                     saveFileDialog.Filter = "png|*.png|bmp|*.bmp|jpg|*.jpg|gif|*.gif";

 64:                     if (saveFileDialog.ShowDialog() != DialogResult.Cancel)

 65:                     {

 66:                         bit.Save(saveFileDialog.FileName);

 67:                     }

 68:                 }

 69:                 else

 70:                 {

 71:                     Clipboard.SetImage(bit);

 72:                 }

 73:                 g.Dispose();

 74:             }

 75:             this.WindowState = FormWindowState.Normal;

 76:             this.FormBorderStyle = FormBorderStyle.FixedSingle;

 77:             panel1.Visible = true;

 78:             this.Opacity = 1;

 79:             mouseDown = false;

 80:         }

 81:

 82:         private void Form1_MouseMove(object sender, MouseEventArgs e)

 83:         {

 84:             if (mouseDown)

 85:             {

 86:                 if (size.Width != 0 && size.Height != 0 && havePainted)

 87:                 {

 88:                     ControlPaint.DrawReversibleFrame(new Rectangle(start1, size), Color.Transparent, FrameStyle.Dashed);

 89:                 }

 90:                 end1 = GetRealPoint(e.Location);

 91:                 size.Width = Math.Abs(end1.X - start.X);

 92:                 size.Height = Math.Abs(end1.Y - start.Y);

 93:                 start1.X = (start.X > end1.X) ? end1.X : start.X;

 94:                 start1.Y = (start.Y > end1.Y) ? end1.Y : start.Y;

 95:

 96:                 if (size.Width != 0 && size.Height != 0)

 97:                 {

 98:                     ControlPaint.DrawReversibleFrame(new Rectangle(start1, size), Color.Transparent, FrameStyle.Dashed);

 99:                     havePainted = true;

100:                 }

101:             }

102:         }

103:

104:         private void button2_Click(object sender, EventArgs e)

105:         {

106:             ReadyToCaptrue();

107:             saveFile = false;

108:         }

109:

110:         private void Form1_Load(object sender, EventArgs e)

111:         {

112:

113:         }

114:

115:         private void ReadyToCaptrue()

116:         {

117:             this.Opacity = 0.1;

118:             panel1.Visible = false;

119:             this.FormBorderStyle = FormBorderStyle.None;

120:             this.WindowState = FormWindowState.Maximized;

121:         }

122:

123:         private Point GetRealPoint(Point position)

124:         {

125:             position.X -= 0;

126:             position.Y -= 0;

127:             return position;

128:         }

129:     }

130: }

131: