GDI++绘图问题

截图--控件截图

//control.CopyFromScreen
    //ok  
    //Rectangle rectangleBounds = pbx.Bounds;
    //Bitmap bit = new Bitmap(rectangleBounds.Width, rectangleBounds.Height);//实例化一个和窗体一样大的bitmap
    //Graphics g = Graphics.FromImage(bit);
    //g.CompositingQuality = CompositingQuality.HighQuality;//质量设为最高
    ////g.CopyFromScreen(pbx.Left, pbx.Top, 0, 0, new Size(pbx.Width, pbx.Height));//保存整个窗体为图片
    //g.CopyFromScreen(pbx.PointToScreen(Point.Empty), Point.Empty, pbx.Size);//保存整个窗体为图片
    ////g.CopyFromScreen(panel游戏区 .PointToScreen(Point.Empty), Point.Empty, panel游戏区.Size);//只保存某个控件（这里是panel游戏区）
    //bit.Save("签名.png");//默认保存格式为PNG，保存成jpg格式质量不是很好

    //////保存dataGridView1截图
    //Bitmap newbitmap = new Bitmap(pbx.Width, pbx.Height);
    //pbx.DrawToBitmap(newbitmap, new Rectangle(0, 0, newbitmap.Width, newbitmap.Height));
    //newbitmap.Save("签名pbx.DrawToBitmap.png"); 

 

读取指纹文件图片，加载在picturebox中

/// <summary>
  /// 创建画布的画板背景
  /// </summary>
  Bitmap backgroundImage = null;
  
  //this.pbx.BackgroundImage = System.Drawing.Image.FromFile(tempPath);
  using (FileStream ms = File.OpenRead(tempPath))
  {
      //File.WriteAllBytes("Fingerprint222.bmp", File.ReadAllBytes("11.png"));
      //File.WriteAllBytes("Fingerprint.bmp", imageBufFingerprint);

      //解决内存异常问题，以及this.pbx.BackgroundImage = System.Drawing.Image.FromStream(ms)导致的一般性gdi+ 问题
      using (Bitmap bt = new Bitmap(ms))
      {
          backgroundImage = new Bitmap(bt.Width, bt.Height);
          //Graphics g = pbx.CreateGraphics();
          Graphics g = Graphics.FromImage(backgroundImage);
          //g.DrawLine(Pens.Black, startPoint, e.Location);
          //g.Clear(Color.White);
          //Pen myPen = new Pen(Color.Black, int.TryParse(ConfigurationManager.AppSettings["penwidth"], out int penwidth) ? penwidth : 3);
          g.SmoothingMode = SmoothingMode.AntiAlias;
          g.CompositingQuality = CompositingQuality.HighQuality;
          g.CompositingMode = CompositingMode.SourceOver;
          g.DrawImage(bt, bt.Width, bt.Height);
          //PointF pointFstart = PointToPointF(startPoint);
          //PointF pointFend = PointToPointF(e.Location);
          //g.DrawBeziers(myPen, new PointF[] { pointFstart, pointFend });
          pbx.BackgroundImage = backgroundImage;
          g.Dispose();

          //bt.Save("Fingerprint.jpg");
          //this.pbx.BackgroundImage = System.Drawing.Image.FromStream(ms);
      }
  }
  //解决提示内存异常错误
  GC.Collect();

 

bmp转png 设置透明度

var  imagezzRaw2Bmp=System.IO.File.ReadAllBytes("Fingerprint.bmp");
    using (Bitmap bitmap = new Bitmap(new MemoryStream(imagezzRaw2Bmp)))
    //using (Bitmap bitmap = new Bitmap("Fingerprint.bmp"))
    {
        //bitmap.MakeTransparent(Color.FromArgb(0, Color.Transparent));
        bitmap.MakeTransparent(Color.FromArgb(0, Color.White));//设置指定颜色为透明。白色
        bitmap.Save("Fingerprint.png");
        //var bitmap1 = Untils.GeneralConvert(bitmap, Color.Blue);
        //bitmap1.Save(@"01.png");
    }

 

bmp图片缩放问题

/// <summary>
/// 缩小比例
/// </summary>
/// <param name="originalSize"></param>
/// <param name="targetSize"></param>
/// <returns></returns>
public static Size CalculateNewSize(Size originalSize, Size targetSize)
{
    int newWidth, newHeight;
    // 如果原始宽度大于目标宽度，则按宽度比例缩放
    if (originalSize.Width > targetSize.Width)
    {
        newWidth = targetSize.Width;
        newHeight = (int)(((float)originalSize.Height) * (float)((float)targetSize.Width / (float)originalSize.Width));
    }
    // 如果原始高度大于目标高度，则按高度比例缩放
    else if (originalSize.Height > targetSize.Height)
    {
        newHeight = targetSize.Height;
        newWidth = originalSize.Width * targetSize.Height / originalSize.Height;
    }
    // 如果原始尺寸小于或等于目标尺寸，则不需要缩放
    else
    {
        newWidth = originalSize.Width;
        newHeight = originalSize.Height;
    }

    return new Size(newWidth, newHeight);
}

/// <summary>
/// 放大缩小
/// </summary>
/// <param name="originalSize"></param>
/// <param name="targetSize"></param>
/// <param name="isScale"></param>
/// <returns></returns>
public static Size CalculateSize(Size originalSize, Size targetSize, bool isScale = true)
{
    int newWidth, newHeight;
    if (isScale)
    {
        // 如果原始宽度大于目标宽度，则按宽度比例缩放
        if (originalSize.Width > targetSize.Width)
        {
            newWidth = targetSize.Width;
            newHeight = originalSize.Height * targetSize.Width / originalSize.Width;
        }
        // 如果原始高度大于目标高度，则按高度比例缩放
        else if (originalSize.Height > targetSize.Height)
        {
            newHeight = targetSize.Height;
            newWidth = originalSize.Width * targetSize.Height / originalSize.Height;
        }
        // 如果原始尺寸小于或等于目标尺寸，则不需要缩放
        else
        {
            newWidth = originalSize.Width;
            newHeight = originalSize.Height;
        }
    }
    else
    {
        // 如果原始宽度大于目标宽度，则按宽度比例放大
        if (originalSize.Width < targetSize.Width)
        {
            newWidth = targetSize.Width;
            newHeight = targetSize.Height * targetSize.Width / originalSize.Width;
        }
        // 如果原始高度大于目标高度，则按高度比例缩放
        else if (originalSize.Height < targetSize.Height)
        {
            newHeight = targetSize.Height;
            newWidth = originalSize.Width * targetSize.Height / originalSize.Height;
        }
        // 如果原始尺寸小于或等于目标尺寸，则不需要缩放
        else
        {
            newWidth = originalSize.Width;
            newHeight = originalSize.Height;
        }
    }
    return new Size(newWidth, newHeight);
}


调用
  //缩小保存
  int signWidth = int.TryParse(ConfigurationManager.AppSettings["fingerprintWidth"], out int signwidth) ? signwidth : 25;
  int signHeight = int.TryParse(ConfigurationManager.AppSettings["fingerprintHeight"], out int signheight) ? signheight : 36;

  // 计算等比缩放后的尺寸
  Size newSize = Untils.CalculateNewSize(pbxFingerprint.Image.Size, new Size(signWidth, signHeight));

  using (Bitmap resizedImage = new Bitmap(pbxFingerprint.Image, newSize))
  {

      // 获取PNG图像编码器
      ImageCodecInfo imageCodecInfo = Untils.GetEncoderInfo("image/png"); //ImageCodecInfo.GetImageEncoders().Where(a=>a.MimeType== "image/png").First();
      // 设置PNG图像编码参数
      EncoderParameters encoderParameters = new EncoderParameters(1);
      EncoderParameter encoderParameter = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L); // 设置质量为100%
      encoderParameters.Param[0] = encoderParameter;

      // 保存Bitmap为PNG格式
      //bitmap.MakeTransparent(Color.FromArgb(0, Color.Transparent));
      resizedImage.MakeTransparent(Color.FromArgb(0, Color.White));//设置指定颜色为透明。白色
      resizedImage.Save(tempLocalFingerPrintPath, imageCodecInfo, encoderParameters);
  }