Graphics.DrawImage 方法连续放大图层反而缩小了

矛盾体小智_Klio · 发表于 2014-9-10 17:54:18

如题，我使用的是Graphics.DrawImage 方法 (Image, Rectangle, Rectangle, GraphicsUnit)拖出一个矩形框放大，第一次放大很成功，将矩形框内容放大成之前的整个图层的尺寸，但在此基础上连续第二次放大则反而变小了

[C#] 纯文本查看 复制代码

                    smallmap = new Bitmap(bmp, pictureBox1.Width, pictureBox1.Height);

                    graphics = pictureBox1.CreateGraphics();//图形创建
                    graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
                    graphics.Clear(Color.White);
               
                    Rectangle D = new Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height);//何必创两个矩形？
                    Rectangle C = new Rectangle(start.X, start.Y, w, h);//D是放大前的图形，C是放大后的图形
                    graphics.DrawImage(smallmap, D, C, GraphicsUnit.Pixel);


                    graphics.Dispose();

这是部分代码，求大神指教

站长苏飞 · 发表于 2014-9-10 18:10:03

你调试看看，应该是中间代码有问题。我估计是逻辑问题

矛盾体小智_Klio · 发表于 2014-9-10 18:56:42

站长苏飞发表于 2014-9-10 18:10
你调试看看，应该是中间代码有问题。我估计是逻辑问题

调了的，大致问题就是在第二次放大的时候，我拖出的矩形框还是建立在最初的图层上的，而不是放大后的图层上的

站长苏飞 · 发表于 2014-9-10 19:21:41

那安逻辑就是第二次的没有存储成功吧

ching126 · 发表于 2014-9-11 09:40:19

楼主需要将第一次放大的图做临时存储然后和从新赋值给picturebox,然后第二次放大的时候再以picturebox图为基础方法即可，这个之前遇到过相同的问题，目前我是这么解决的，祝楼主好运

矛盾体小智_Klio · 发表于 2014-9-11 19:46:00

ching126 发表于 2014-9-11 09:40
楼主需要将第一次放大的图做临时存储然后和从新赋值给picturebox,然后第二次放大的时候再以picturebox图为 ...

谢谢，我试试

矛盾体小智_Klio · 发表于 2014-9-13 00:33:33

ching126 发表于 2014-9-11 09:40
楼主需要将第一次放大的图做临时存储然后和从新赋值给picturebox,然后第二次放大的时候再以picturebox图为 ...

亲，我没弄成功，你能发个事例代码给我吗···我如何把smallmap替换成矩形框出来的图

ching126 · 发表于 2014-9-13 10:26:43

我这个是有5个小图片框，然后选中一个之后再将选中的图像加载到大图片框中，然后在大图片框汇总选择一块区域填充到刚才选中了小图片框中，至于你的事放大，则需要等图片等比例放大即可，下面是实例代码，您可以安装您的需要修改，这个是将图片打开到图片框
private void btnOpenImage_Click(object sender, EventArgs e)
      {
         //图像比原图缩小了40%，缩到60%的大小了
         OpenFileDialog ofd = new OpenFileDialog();
         ofd.AddExtension = true;
         ofd.Multiselect = true;
         ofd.DefaultExt = "jpg|bmp";
         ofd.Filter = "bmp files (*.bmp)|*.bmp|jpg files (*.jpg)|*.jpg";  //|All files(*.*)|*.*
         ofd.FilterIndex = 1;
         int index = 0;
         if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
         {
            PictureBox tempPicb = null;
            Label tempLabel = null;
            CheckBox tempChk = null;
            //Random rand = new Random();
            //int n = rand.Next(1, 999);
            if (ht.Count <= 0)  //pb == null &&
            {
                  for (int i = 0; i < ofd.FileNames.Length; i++)
                  {
                     tempPicb = SelectedPictureBox(i + 1);
                     tempLabel = GetCurrentLabel(i + 1);
                     tempChk = GetCurrentCheckBox(i + 1);

                     tempPicb.SizeMode = PictureBoxSizeMode.Zoom;
                     tempPicb.Image = Image.FromFile(ofd.FileNames[i]);

                     //n = rand.Next(1, 999) == n ? rand.Next(1, 999) : n;
                     //tempLabel.Text = n + "_" + ofd.SafeFileNames[i];  // + ofd.DefaultExt;
                     tempLabel.Text = ofd.SafeFileNames[i];  // + ofd.DefaultExt;
                     tempChk.Checked = true;
                  }
            }
            else if (ht.Count <= 1)
            {
                  //这里只是修改一个或者替换一个图像
                  foreach (DictionaryEntry de in ht)
                  {
                     tempPicb = (PictureBox)de.Value;
                     tempLabel = GetCurrentLabel(Convert.ToInt32(de.Key));
                     tempChk = GetCurrentCheckBox(Convert.ToInt32(de.Key));

                     tempPicb.SizeMode = PictureBoxSizeMode.Zoom;
                     tempPicb.Image = Image.FromFile(ofd.FileNames[index]);

                     //n = rand.Next(1, 999) == n ? rand.Next(1, 999) : n;
                     //tempLabel.Text = n + "_" + ofd.SafeFileNames[index];
                     tempLabel.Text = ofd.SafeFileNames[index];
                     tempChk.Checked = true;

                     picbOriginalImage.SizeMode = PictureBoxSizeMode.Zoom;
                     picbOriginalImage.Image = tempPicb.Image;
                     lbImageName.Text = tempLabel.Text;
                  }
            }
            else  //if (ht.Count > 1)
            {
                  foreach (DictionaryEntry de in ht)
                  {
                     tempPicb = (PictureBox)de.Value;
                     tempLabel = GetCurrentLabel(Convert.ToInt32(de.Key));
                     tempChk = GetCurrentCheckBox(Convert.ToInt32(de.Key));

                     tempPicb.SizeMode = PictureBoxSizeMode.Zoom;
                     tempPicb.Image = Image.FromFile(ofd.FileNames[index]);

                     //n = rand.Next(1, 999) == n ? rand.Next(1, 999) : n;
                     //tempLabel.Text = n +"-" + ofd.SafeFileNames[index];
                     tempLabel.Text = ofd.SafeFileNames[index];
                     tempChk.Checked = true;

                     index++;
                     if (index >= ofd.FileNames.Length)
                     {
                        break;
                     }
                  }
            }
            //ht.Clear();

            tempPicb = null;
         }
      }
图片框的选中
/// <summary>
      /// 图像的点击事件
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void PictureBox_Click(object sender, EventArgs e)
      {
         object tag = ((PictureBox)sender).Tag;
         g_i_Flag = Convert.ToInt32(tag);
         //Image image = null;
         //pb = (PictureBox)sender;  //将选中的对象给pb
         PictureBox tempPb = (PictureBox)sender;
         pb = tempPb;
         if ((Control.ModifierKeys & Keys.Control) == Keys.Control)
         {
            //MessageBox.Show("Ctrl键被按下");
            //选中时改变样式
            SelectedPictureBoxToStyle(g_i_Flag, true);
            ht.Remove(tag);
            ht.Add(tag, tempPb);  //如果按下ctrl键选中那个添加那个
         }
         else
         {
            //移除所有之前选中的图像
            ht.Clear();
            ht.Add(tag, tempPb);
            pictureBox1.BorderStyle = BorderStyle.FixedSingle;
            pictureBox2.BorderStyle = BorderStyle.FixedSingle;
            pictureBox3.BorderStyle = BorderStyle.FixedSingle;
            pictureBox4.BorderStyle = BorderStyle.FixedSingle;
            pictureBox5.BorderStyle = BorderStyle.FixedSingle;
            //((PictureBox)sender).BorderStyle = BorderStyle.Fixed3D;
            SelectedPictureBoxToStyle(g_i_Flag, true);
            lb = GetCurrentLabel(g_i_Flag);
            //image = pb.Image;
            //pb = null;
            if (tempPb.Image == null)
                  return;
            //panel1.BackgroundImage = Image.FromFile(opf.FileName);
            g_img_image = tempPb.Image;
            picbOriginalImage.SizeMode = PictureBoxSizeMode.Zoom;
            picbOriginalImage.Image = g_img_image;
            lbImageName.Text = lb.Text;

            srcImage = g_img_image;
            srcWidth = srcImage.Width;
            srcHeight = srcImage.Height;

            thumbWidth = picbOriginalImage.Width;
            thumbHeight = picbOriginalImage.Height;

         }


         tempPb = null;
      }
鼠标按下事件
/// <summary>
      /// 鼠标在图像上按下事件
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void Image_MouseDown(object sender, MouseEventArgs e)
      {
         if (e.Button == System.Windows.Forms.MouseButtons.Left)
         {
            //记录鼠标按下时的坐标位置
            startPosX = e.X;
            startPosY = e.Y;
            isDraw = true;

            //这里需要界定当鼠标按下的是左键时，鼠标区域控制，不能出picturebox框
            //Point point = this.PointToScreen(new Point(19, 203));  //将窗体计算成屏幕坐标
            Point point = this.PointToScreen(groupBox2.Location);  //将窗体计算成屏幕坐标
            point.X = point.X + picbOriginalImage.Location.X;
            point.Y = point.Y + picbOriginalImage.Location.Y;
            int offsetX = groupBox2.Location.X + picbOriginalImage.Location.X;
            int offsetY = groupBox2.Location.Y + picbOriginalImage.Location.Y;

            //Point point = new Point(100, 100);
            //Point point = this.PointToClient(new Point(0, 0));  //将屏幕坐标计算成窗体
            //this.ClientRectangle.Width, this.ClientRectangle.Height
            Rectangle rect = new Rectangle(point, new Size(this.ClientSize.Width - offsetX - 125, this.ClientSize.Height - offsetY - 17));
            Cursor.Clip = rect;
            //MessageBox.Show(picbOriginalImage.Location.X + "," + picbOriginalImage.Location.Y + ";"
            //+ groupBox2.Location.X + "," + groupBox2.Location.Y);
         }
         else
         {
            //说明按下的不是左键而是右键，这时需要重绘控件和子控件
            Refresh();
         }
      }
鼠标在图像上抬起事件
/// <summary>
      /// 鼠标在图像上抬起事件
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void Image_MouseUp(object sender, MouseEventArgs e)
      {
         isDraw = false;
         g.Dispose();
         bool isReplaceImage = false;
         #region
         //将原图绘制成大小适中的小图
         //Bitmap srcBmp = new Bitmap(srcWidth, srcHeight, PixelFormat.Format32bppArgb);
         //Graphics srcG = Graphics.FromImage(srcBmp);
         //srcG.InterpolationMode = InterpolationMode.HighQualityBicubic;
         //srcG.SmoothingMode = SmoothingMode.AntiAlias;
         //srcG.DrawImage(srcImage, Point.Empty);
         //srcG.Flush();  //FlushIntention.Flush

         ////再选取小图中的区域
         //Bitmap dstBmp = new Bitmap(dstWidth, dstHeight, PixelFormat.Format32bppArgb);
         //Graphics dstG = Graphics.FromImage(dstBmp);
         //dstG.DrawImage(srcBmp, 0, 0, new Rectangle(X, Y, dstWidth, dstHeight), GraphicsUnit.Pixel);
         //dstG.Flush();

         //dstG.Dispose();

         //dstImage = dstBmp;

         //pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
         //pictureBox1.Image = dstImage;
         #endregion

         //这里需要界定，当鼠标抬起时解除鼠标区域控制
         Screen[] srceens = Screen.AllScreens;
         Cursor.Clip = srceens[0].Bounds;

         if (e.Button == System.Windows.Forms.MouseButtons.Right)
            return;
         if (dstWidth <= 27 || dstHeight <= 20)
         {
            //MessageBox.Show("所选区域宽度不能小于27像素,高度不能小于20像素！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
         }
         //如果pb==null的话说明没有选中picturebox
         if (pb == null)
         {
            return;
         }
         else
         {
            //说明选中了其中的picturebox，在判断选中的picturebox有没有image
            //if (pb.Image != null)
            //{
            // if (MessageBox.Show("确定要替换打印 " + g_i_Flag + " 的原图像吗？", "提示", MessageBoxButtons.OKCancel,
            //          MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == System.Windows.Forms.DialogResult.OK)
            // {
            //       isReplaceImage = true;
            // }
            // else
            // {
            //       isReplaceImage = false;
            // }
            //}
            //else
            //{
            // isReplaceImage = true;
            //}
            isReplaceImage = true;
         }

         //说明需要替换
         if (isReplaceImage)
         {
            DrawSelectedImage();
         }

         //pb = null;

      }
鼠标在图片上移动事件
/// <summary>
      /// 鼠标在图像上移动事件
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void Image_MouseMove(object sender, MouseEventArgs e)
      {
         endPosX = e.X;
         endPosY = e.Y;

         if (isDraw)
         {
            Refresh();
            //picbOriginalImage.Invalidate();
         }
      }
/// <summary>
      /// 绘画
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void Image_Paint(object sender, PaintEventArgs e)
      {
         //if (pb == null)
         g = e.Graphics;
         //g = picbOriginalImage.CreateGraphics();
         //if (image == null)
         // return;
         //g = Graphics.FromImage(image);
         //else
         //g = pb.CreateGraphics();
         if (isDraw)
         {
            //设置虚线格式
            //Dash短线段，DashDot短线段和点，DashDotDot短线段点点，Dot点，Solid实线
            pen.DashStyle = DashStyle.Dash;
            //设置宽度和高度
            dstWidth = endPosX - startPosX;
            dstHeight = endPosY - startPosY;
            //if (picbOriginalImage.Image == null)
            // return;
            //判断开始点结束点是从哪个方向到哪个方向
            if (dstWidth < 0 && dstHeight < 0)
            {
                  X = endPosX;
                  Y = endPosY;
                  dstWidth = Math.Abs(dstWidth);
                  dstHeight = Math.Abs(dstHeight);
            }
            else if (dstWidth < 0)
            {
                  X = endPosX;
                  Y = startPosY;
                  dstWidth = Math.Abs(dstWidth);
            }
            else if (dstHeight < 0)
            {
                  X = startPosX;
                  Y = endPosY;
                  dstHeight = Math.Abs(dstHeight);
            }
            else
            {
                  X = startPosX;
                  Y = startPosY;
            }

            //目标矩形
            Rectangle dstRectangle = new Rectangle(X, Y, dstWidth, dstHeight);
            //这个是使用图像填充内部
            //TextureBrush texture = new TextureBrush(srcImage);
            //texture.WrapMode = WrapMode.Tile;

            //画图像,这里需要填充到上面选中的框中
            //g.DrawImageUnscaledAndClipped(image, dstRectangle);

            //给矩形画填充内容
            //g.DrawImage(srcImage, X, Y, dstRectangle, GraphicsUnit.Pixel);
            //给矩形填充内容
            //g.FillRectangle(texture, dstRectangle);

            //画矩形框
            g.DrawRectangle(pen, dstRectangle);

         }
      }
为刚才选区填充图像
/// <summary>
      /// 为选中的区域填充图像
      /// </summary>
      private void DrawSelectedImage()
      {
         try
         {
            //将原图绘制成大小适中的小图
            Bitmap thumbBmp = new Bitmap(thumbWidth, thumbHeight, PixelFormat.Format32bppArgb);
            Graphics thumbG = Graphics.FromImage(thumbBmp);

            thumbG.InterpolationMode = InterpolationMode.High;
            thumbG.SmoothingMode = SmoothingMode.HighQuality;
            thumbG.CompositingQuality = CompositingQuality.HighQuality;

            Rectangle thumbRectangle = new Rectangle(0, 0, thumbWidth, thumbHeight);
            thumbG.DrawImage(srcImage, thumbRectangle, 0, 0, srcWidth, srcHeight, GraphicsUnit.Pixel);
            thumbG.Flush();  //FlushIntention.Flush
            thumbG.Dispose();

            //再选取小图中的区域
            Bitmap dstBmp = new Bitmap(dstWidth, dstHeight, PixelFormat.Format32bppArgb);
            Graphics dstG = Graphics.FromImage(dstBmp);
            Rectangle dstRectangle = new Rectangle(X, Y, dstWidth, dstHeight);
            dstG.DrawImage(thumbBmp, 0, 0, dstRectangle, GraphicsUnit.Pixel);
            dstG.Flush();
            dstG.Dispose();

            dstImage = dstBmp;

            //ImageToSelectedPictureBox(g_i_Flag);
            //pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
            //pictureBox1.Image = dstImage;
            //((PictureBox)((object)(pb.Name))).SizeMode = PictureBoxSizeMode.Zoom;
            //((PictureBox)((object)(pb.Name))).Image = dstImage;
            pb.SizeMode = PictureBoxSizeMode.Zoom;
            pb.Image = dstImage;
            //dstImage = null;
            //thumbBmp.Dispose();
            thumbBmp = null;
            //dstBmp.Dispose();
            dstBmp = null;
         }
         catch (Exception)
         {
            //
         }
      }
我这个最后返回的是image,您可以保存也可以做处理都可以

ching126 · 发表于 2014-9-13 10:29:42

我的是5个图片框，对应有5个label,用来临时存储打开的图片的名称，然后选中那个绘制矩形之后需要保存的，还要有图片名称，所有以上代码您可以自己优化下

矛盾体小智_Klio · 发表于 2014-9-13 20:54:00

ching126 发表于 2014-9-13 10:29
我的是5个图片框，对应有5个label,用来临时存储打开的图片的名称，然后选中那个绘制矩形之后需要保存的，还 ...

收到了，谢谢

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[学生提问] Graphics.DrawImage 方法连续放大图层反而缩小了