说明：
c#使用forms实现屏幕截图
step1: 点击按钮，拖拽，截图，保存本地
C:\Users\wangrusheng\RiderProjects\WinFormsApp1\WinFormsApp1\Form1.cs
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;namespace WinFormsApp1
{public partial class Form1 : Form{public Form1(){InitializeComponent();// 添加Label控件Label label = new Label();label.Text = "拖拽选择区域截图";label.AutoSize = true;label.Location = new Point(20, 20);this.Controls.Add(label);// 添加截图按钮Button screenshotButton = new Button();screenshotButton.Text = "开始截图";screenshotButton.Location = new Point(20, 50);screenshotButton.Click += ScreenshotButton_Click;this.Controls.Add(screenshotButton);}private void ScreenshotButton_Click(object sender, EventArgs e){this.Hide();using (var selector = new RegionSelector()){if (selector.ShowDialog() == DialogResult.OK){SaveScreenshot(selector.SelectedRegion);}}this.Show();}private void SaveScreenshot(Rectangle region){using (Bitmap bmp = new Bitmap(region.Width, region.Height)){using (Graphics g = Graphics.FromImage(bmp)){g.CopyFromScreen(region.Location, Point.Empty, region.Size);}SaveFileDialog sfd = new SaveFileDialog();sfd.Filter = "PNG 图片|*.png|JPEG 图片|*.jpg";sfd.Title = "保存截图";if (sfd.ShowDialog() == DialogResult.OK){ImageFormat format = sfd.FilterIndex switch{1 => ImageFormat.Png,2 => ImageFormat.Jpeg,_ => ImageFormat.Png};bmp.Save(sfd.FileName, format);MessageBox.Show($"截图已保存至：{sfd.FileName}", "操作成功");}}}}public class RegionSelector : Form{private Point start;private Rectangle selection;private bool selecting;public Rectangle SelectedRegion => selection;public RegionSelector(){this.FormBorderStyle = FormBorderStyle.None;this.WindowState = FormWindowState.Maximized;this.Opacity = 0.3;this.DoubleBuffered = true;this.TopMost = true;this.Cursor = Cursors.Cross;this.BackColor = Color.Black;this.MouseDown += (s, e) => StartSelection(e);this.MouseMove += (s, e) => UpdateSelection(e);this.MouseUp += (s, e) => EndSelection();this.KeyDown += (s, e) => { if (e.KeyCode == Keys.Escape) CancelSelection(); };}private void StartSelection(MouseEventArgs e){if (e.Button == MouseButtons.Left){start = Control.MousePosition;selecting = true;}}private void UpdateSelection(MouseEventArgs e){if (selecting){Point current = Control.MousePosition;selection = new Rectangle(Math.Min(start.X, current.X),Math.Min(start.Y, current.Y),Math.Abs(start.X - current.X),Math.Abs(start.Y - current.Y));Invalidate();}}private void EndSelection(){if (selection.Width > 0 && selection.Height > 0){DialogResult = DialogResult.OK;}Close();}private void CancelSelection(){selection = Rectangle.Empty;Close();}protected override void OnPaint(PaintEventArgs e){base.OnPaint(e);if (selecting && !selection.IsEmpty){Rectangle screenRect = RectangleToClient(RectangleToScreen(selection));using (Pen pen = new Pen(Color.Red, 2)){e.Graphics.DrawRectangle(pen, screenRect);}}}protected override void OnFormClosed(FormClosedEventArgs e){base.OnFormClosed(e);Cursor.Current = Cursors.Default;}}
}
step2:简单截取整个屏幕 C:\Users\wangrusheng\RiderProjects\WinFormsApp1\WinFormsApp1\Form1.cs
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;namespace WinFormsApp1;public partial class Form1 : Form
{public Form1(){InitializeComponent();// 添加Label控件Label label = new Label();label.Text = "Hello World!";label.AutoSize = true;label.Location = new Point(20, 20);this.Controls.Add(label);// 添加截图按钮Button screenshotButton = new Button();screenshotButton.Text = "截图";screenshotButton.Location = new Point(20, 50);screenshotButton.Click += ScreenshotButton_Click; // 绑定点击事件this.Controls.Add(screenshotButton);}private void ScreenshotButton_Click(object sender, EventArgs e){// 获取主屏幕的尺寸Rectangle screenSize = Screen.PrimaryScreen.Bounds;// 创建位图对象using (Bitmap screenshot = new Bitmap(screenSize.Width, screenSize.Height)){// 使用Graphics对象捕获屏幕using (Graphics graphics = Graphics.FromImage(screenshot)){graphics.CopyFromScreen(Point.Empty, Point.Empty, screenSize.Size);}// 显示保存文件对话框SaveFileDialog saveDialog = new SaveFileDialog();saveDialog.Filter = "PNG 图片|*.png|JPEG 图片|*.jpg";saveDialog.Title = "保存截图";if (saveDialog.ShowDialog() == DialogResult.OK){// 根据用户选择的格式保存ImageFormat format = saveDialog.FilterIndex switch{1 => ImageFormat.Png,2 => ImageFormat.Jpeg,_ => ImageFormat.Png};screenshot.Save(saveDialog.FileName, format);MessageBox.Show($"截图已保存至：{saveDialog.FileName}", "操作成功");}}}
}
end
