87 lines
2.9 KiB
C#
87 lines
2.9 KiB
C#
using System.Drawing;
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using System.Drawing.Imaging;
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using System.Runtime.InteropServices;
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namespace DeviceAgent.Services;
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/// <summary>
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/// 屏幕截图服务
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/// </summary>
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public class ScreenCaptureService
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{
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private readonly ILogger<ScreenCaptureService> _logger;
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public ScreenCaptureService(ILogger<ScreenCaptureService> logger)
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{
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_logger = logger;
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}
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/// <summary>
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/// 截取屏幕并返回 JPEG 字节数组
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/// </summary>
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/// <param name="quality">JPEG 质量 (1-100)</param>
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/// <param name="maxWidth">最大宽度（用于缩略图）</param>
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public byte[] CaptureScreen(int quality = 50, int maxWidth = 800)
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{
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try
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{
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// 获取主屏幕尺寸
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var screenWidth = GetSystemMetrics(SM_CXSCREEN);
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var screenHeight = GetSystemMetrics(SM_CYSCREEN);
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using var bitmap = new Bitmap(screenWidth, screenHeight, PixelFormat.Format24bppRgb);
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using var graphics = Graphics.FromImage(bitmap);
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// 截取整个屏幕
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graphics.CopyFromScreen(0, 0, 0, 0, new Size(screenWidth, screenHeight));
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// 计算缩放后的尺寸
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var scale = Math.Min(1.0, (double)maxWidth / screenWidth);
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var newWidth = (int)(screenWidth * scale);
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var newHeight = (int)(screenHeight * scale);
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// 缩放图片
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using var resized = new Bitmap(newWidth, newHeight);
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using var resizeGraphics = Graphics.FromImage(resized);
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resizeGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;
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resizeGraphics.DrawImage(bitmap, 0, 0, newWidth, newHeight);
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// 转换为 JPEG
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using var ms = new MemoryStream();
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var encoder = GetEncoder(ImageFormat.Jpeg);
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var encoderParams = new EncoderParameters(1);
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encoderParams.Param[0] = new EncoderParameter(Encoder.Quality, (long)quality);
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resized.Save(ms, encoder, encoderParams);
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return ms.ToArray();
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}
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catch (Exception ex)
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{
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_logger.LogError(ex, "屏幕截图失败");
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return Array.Empty<byte>();
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}
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}
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/// <summary>
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/// 截取屏幕并返回 Base64 字符串
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/// </summary>
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public string CaptureScreenBase64(int quality = 50, int maxWidth = 800)
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{
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var bytes = CaptureScreen(quality, maxWidth);
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return bytes.Length > 0 ? Convert.ToBase64String(bytes) : string.Empty;
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}
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private static ImageCodecInfo GetEncoder(ImageFormat format)
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{
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var codecs = ImageCodecInfo.GetImageEncoders();
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return codecs.First(c => c.FormatID == format.Guid);
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}
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// Windows API
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private const int SM_CXSCREEN = 0;
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private const int SM_CYSCREEN = 1;
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[DllImport("user32.dll")]
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private static extern int GetSystemMetrics(int nIndex);
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}
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