C# Winform画图

实验二：用winform实现画图

实验目的

构造属于你的专属画图程序，可参考系统自带的绘图板

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环境

1. 操作系统： Windows 10 X64
2. IDE： visual studio 2017
3. 语言：C#

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界面布局及控件使用

• 整个页面 ：Panel
• 文件菜单 ：MenuStrip
• 主页，查看菜单 ：TabControl
• 绘图板 ：PictureBox
• 控制绘图板大小 ：PictureBox
• 工具、图形按钮 ：Button
• 粗细 ：Label
• 实线虚线 ：Label
• 填充按钮 ：Label
• 功能模块分区 ：Panel
• 功能模块分区的名字 :Label
• 颜色板 ：自定义控件名为 userControl1
• 左下角的实时坐标 ：StatusStrip
• 按钮的文本提示 ： ToolTip

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界面展示

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Point1–画布画板

画布相当于一张纸，我们使用两张纸，一张originalimage用于保留最终绘图并贴在画板上；一张interimage用于保存中间绘图痕迹。
比如画一个矩形

1. 画图前先将中间画布初始化为原始画布（去掉绘图痕迹）
2. 将矩形画在在中间画布
3. 在鼠标释放时将中间画布复制给原始画布
4. 将原始画布贴到画板上

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Point2–颜色板的实现

新建及使用

1. 新建项目->选择visual C# ->Windows 桌面 ->Windows窗体控件库
2. 完成编辑后，在项目文件中找到 bin文件下的后缀为.dll的文件拖拽进工具箱即可。

完成效果：

使用的控件：

• 颜色按钮：Button
• 编辑颜色按钮：ColorDialog
• 颜色1,2面板：Panel

功能实现：

1. 选择颜色，判断改变颜色1还是颜色2

     private void button_Click(object sender, EventArgs e)
   {
       Button currentButton = (Button)sender;
       currentLabel.BackColor = currentButton.BackColor; 
       if(currentLabel==label1)
       {
           label1.BackColor = currentButton.BackColor;
           color1 = currentButton.BackColor;
       }
       else
       {
           label7.BackColor = currentButton.BackColor;
           color2 = currentButton.BackColor;
       }
   }
   

2. 颜色1颜色2切换
   方法：设置一个currentlabel指向当前颜色label

      private void color1_Click(object sender, EventArgs e)
    {
            currentLabel = label1;
        label3.BackColor = Color.PowderBlue;
        label4.BackColor = Color.Transparent;
    }
   
    private void color2_Click(object sender, EventArgs e)
    {
        currentLabel = label7;
        label4.BackColor = Color.PowderBlue;
        label3.BackColor = Color.Transparent;
    }
   

3. colordialog 调用颜色对话框，并将颜色添加到可用按钮中
   重点：colorDialog1.ShowDialog()

    private void makecolor_Click(object sender, EventArgs e)
    {
   
        if (colorDialog1.ShowDialog() == DialogResult.OK)
        {
            Color mycolor = colorDialog1.Color;
   
            for (int i = 0; i < haveUse; i++)
            {
                if (allButton[i].BackColor == mycolor)//与第i个重复，则从第i+1个到num-1个都向前移动一格
                {
                    for (int k = i; k < NUM - 1; k++)
                    {
                        allButton[k].BackColor = allButton[k + 1].BackColor;
                    }
                    haveUse--;
                    break;
                }
            }
   
            if (haveUse == NUM)//已经满了，前移一格
            {
                for (int i = 0; i < NUM - 1; i++)
                {
                    allButton[i] = allButton[i + 1];
                }
                allButton[NUM - 1].BackColor = mycolor;
                haveUse++;
            }
            else//还没满
            {
                allButton[haveUse].BackColor = mycolor;
                allButton[haveUse].Enabled = true;
                haveUse++;
            }
        }
    }
   

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Point3–绘制图形

重点：绘制图形的函数

        //使用Graphics对象实现
         switch (type)
        {
            case "nonerh"://无填充菱形
                {
                    PointF[] pointFs = { new PointF(leftX + width / 2, leftY), new PointF(leftX, leftY + height / 2), new PointF(leftX + width / 2, leftY + height), new PointF(leftX + width, leftY + height / 2) };
                    interGraphics.DrawPolygon(mypen, pointFs);
                    break;
                }
            case "solidrh"://纯色菱形
                {
                    PointF[] pointFs = { new PointF(leftX + width / 2, leftY), new PointF(leftX, leftY + height / 2), new PointF(leftX + width / 2, leftY + height), new PointF(leftX + width, leftY + height / 2) };
                    interGraphics.FillPolygon(new SolidBrush(backcolor), pointFs);
                    interGraphics.DrawPolygon(mypen, pointFs);

                    break;
                }
            case "hatchrh"://圆点填充
                {
                    PointF[] pointFs = { new PointF(leftX + width / 2, leftY), new PointF(leftX, leftY + height / 2), new PointF(leftX + width / 2, leftY + height), new PointF(leftX + width, leftY + height / 2) };
                    interGraphics.FillPolygon(new HatchBrush(HatchStyle.LargeConfetti, backcolor, Color.White), pointFs);
                    interGraphics.DrawPolygon(mypen, pointFs);

                    break;
                }

            case "nonetriangle"://无填充等腰三角形
                {
                    PointF[] pointfs = { new PointF((startPoint.X + currentPoint.X) / 2, startPoint.Y), new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.DrawPolygon(mypen, pointfs);
                    break;
                }
            case "solidtriangle"://纯色填充等腰三角形
                {
                    PointF[] pointfs = { new PointF((startPoint.X + currentPoint.X) / 2, startPoint.Y), new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.FillPolygon(new SolidBrush(backcolor), pointfs);
                    interGraphics.DrawPolygon(mypen, pointfs);

                    break;
                }
            case "hatchtriangle"://圆点填充等腰三角形
                {
                    PointF[] pointfs = { new PointF((startPoint.X + currentPoint.X) / 2, startPoint.Y), new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.FillPolygon(new HatchBrush(HatchStyle.LargeConfetti, backcolor, Color.White), pointfs);
                    interGraphics.DrawPolygon(mypen, pointfs);

                    break;
                }
            case "nonetriangle2"://无填充直角三角形
                {
                    PointF[] pointfs = { startPoint, new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.DrawPolygon(mypen, pointfs);
                    break;
                }
            case "solidtriangle2"://纯色填充直角三角形
                {
                    PointF[] pointfs = { startPoint, new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.FillPolygon(new SolidBrush(backcolor), pointfs);
                    interGraphics.DrawPolygon(mypen, pointfs);

                    break;
                }
            case "hatchtriangle2"://圆点填充直角三角形
                {
                    PointF[] pointfs = {startPoint, new PointF(startPoint.X, currentPoint.Y), currentPoint };
                    interGraphics.FillPolygon(new HatchBrush(HatchStyle.LargeConfetti, backcolor, Color.White), pointfs);
                    interGraphics.DrawPolygon(mypen, pointfs);

                    break;
                }
            case "noneline"://直线
                interGraphics.DrawLine(mypen, startPoint, currentPoint);
                break;
            case "nonerectangle"://无填充矩形
                interGraphics.DrawRectangle(mypen, leftX, leftY, width, height);
                break;
            case "noneellipse"://无填充椭圆
                {               
                    interGraphics.DrawEllipse(mypen, leftX, leftY, width, height);
                    break;
                }
            case "nonearc"://弧线
                {                   
                    if (width != 0 && height != 0)
                        interGraphics.DrawArc(mypen, leftX, leftY, width, height, 0, 180);
                    break;
                }
            case "nonepie"://无填充饼形
                {
                   
                    if (width != 0 && height != 0)
                        interGraphics.DrawPie(mypen, leftX, leftY, width, height, 0, 180);
                    break;
                }
            case "solidrectangle"://纯色填充矩形
                {
                    
                    interGraphics.FillRectangle(new SolidBrush(backcolor), leftX, leftY, width, height);
                    interGraphics.DrawRectangle(mypen, leftX, leftY, width, height);
                    break;
                }
            case "solidellipse"://纯色填充椭圆
                {
                    interGraphics.FillEllipse(new SolidBrush(backcolor), leftX, leftY, width, height);
                    interGraphics.DrawEllipse(mypen, leftX, leftY, width, height);
                    break;
                }
            case "solidpie"://纯色填充饼形
                {
                    if (width != 0 && height != 0)
                    {
                        interGraphics.FillPie(new SolidBrush(backcolor), leftX, leftY, width, height, 0, 180);
                        interGraphics.DrawPie(mypen, leftX, leftY, width, height, 0, 180);
                    }
                    break;
                }
            case "hatchrectangle"://圆点填充矩形
                {
                    interGraphics.FillRectangle(new HatchBrush(HatchStyle.LargeConfetti,backcolor,Color.White), leftX, leftY, width, height);
                    interGraphics.DrawRectangle(mypen, leftX, leftY, width, height);
                    break;
                }
            case "hatchellipse"://圆点填充椭圆
                {
                    interGraphics.FillEllipse(new HatchBrush(HatchStyle.LargeConfetti,backcolor,Color.White), leftX, leftY, width, height);
                    interGraphics.DrawEllipse(mypen, leftX, leftY, width, height);
                    break;

                }
            case "hatchpie"://圆点填充饼形
                {
                    if (width != 0 && height != 0)
                    {
                        interGraphics.FillPie(new HatchBrush(HatchStyle.LargeConfetti, backcolor,Color.White), leftX, leftY, width, height, 0, 180);

                        interGraphics.DrawPie(mypen, leftX, leftY, width, height, 0, 180);
                    }
                    break;
                }
        }

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Point4–铅笔

方法：使用DrawLine画线方法 从startpoint 到 currentpoint

    public void Pencile(MouseEventArgs e)//铅笔
    {
        PointF currentPoint = new PointF(e.X-10, e.Y+8);
        Graphics interGraphics = Graphics.FromImage(interImg);
        interGraphics.DrawLine(mypen, startPoint,currentPoint);
        originalImg = (Image)interImg.Clone();
        targetGraphics.DrawImage(originalImg,0,0);
        startPoint = currentPoint;
        
    }

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Point5–橡皮

方法：相当于用纯色矩形覆盖，用DrwaRectangle方法

      public void Eraser(MouseEventArgs e)//橡皮擦
    {
        PointF currentPoint = new PointF(e.X, e.Y);
        Graphics interGraphics = Graphics.FromImage(interImg);
        interGraphics.FillRectangle(new SolidBrush(backcolor), startPoint.X-5,startPoint.Y-5,16,10);
        originalImg = (Image)interImg.Clone();
        targetGraphics.DrawImage(originalImg, 0, 0);
        startPoint = currentPoint;
    }

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Point6–粗细、线条、填充

粗细：设置pen的Width属性

线条：设置pen的DashStyle属性。实现为Solid,虚线为Dot

填充：无填充：使用pen画；纯色填充：先用SolidBrush笔刷画，再用pen画上边；圆点填充：先用HatchBrush笔刷(设置属性HatchStyle.LargeConfetti)画，再用pen画上边

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Point7–文本框

使用TextBox，点击绘图板，当绘图板里没有文本框时，显示文本框；有文本框时，移除文本框并将文本框的文字绘到绘图板上
重点：

1. 动态添加控件：panel10.Controls.Add(mytb);（panel0为父容器）

2. 动态删除控件：panel10.Controls.Remove(control);

3. 绘制文字：interGraphics.DrawString(str, font, brush,pointF);
   font为字体样式，brush为字体填充笔刷，pointF为字体在父容器中的相对位置。

        if (drawtype == "text")
        {
            if (Extentionclass.FindControl(panel10, "mytb") == null)//第一次按下
            {
                TextBox mytb = new TextBox();
                mytb.Name = "mytb";
                mytb.Location = new Point(e.X, e.Y+pictureBox1.Location.Y);//位置
                mytb.BorderStyle = BorderStyle.FixedSingle;
                panel10.Controls.Add(mytb);
                //     panel10.Controls.SetChildIndex(mytb, 100);
                mytb.BringToFront();
            }
            else
            {
                Control control = Extentionclass.FindControl(panel10, "mytb");
                string str =control.Text;
                Font font = new Font("宋体", 9);
                Brush brush = new SolidBrush(userControl11.Color1);
                PointF pointF = new PointF(control.Location.X, control.Location.Y - pictureBox1.Location.Y);
                panel10.Controls.Remove(control);
                Graphics interGraphics = Graphics.FromImage(tool.InterImage);
                         
                
                interGraphics.DrawString(str, font, brush,pointF);
                graphics.DrawImage(tool.InterImage, 0, 0);
            }
        }
   

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Point8–新建文件、保存文件

新建文件之前要判断是否保存文件
用到的方法：

1. 消息提示框：MessageBox.Show(“是否要保存文件”, “系统提示”, MessageBoxButtons.YesNoCancel);

2. 保存、另存为、新建文件：如下代码

3. 新建时要初始化绘画板

      private void 新建ToolStripMenuItem_Click(object sender, EventArgs e)
    {
       //是否保存
        DialogResult dialogResult = MessageBox.Show("是否要保存文件", "系统提示", MessageBoxButtons.YesNoCancel);
        if (dialogResult==DialogResult.Yes)//选择先保存
        {
            if (sFilename != null)//可以直接保存
            {
                if (MessageBox.Show("是否要保存文件？", "系统提示", MessageBoxButtons.YesNo) == DialogResult.Yes)//选择yes保存
                {
                    tool.OriginalImage.Save(sFilename);
                }
            }
            else
            {
                SaveFileDialog saveFile = new SaveFileDialog();
                //            saveFile.FileName = "";
                saveFile.Filter = "JPG|*.jpg;*.jpeg;*.jpe;*.jfif|GIF|*.gif|PNG|*.png|TIF|*.tif;*.tiff|ICO|*.ico|所有文件|*.*";
                if (saveFile.ShowDialog() == DialogResult.OK)//文件夹显示成功
                {
                    sFilename = saveFile.FileName;
                    tool.OriginalImage.Save(sFilename);
                }
            }
        }
        else if(dialogResult==DialogResult.Cancel)//取消则什么都不做直接返回
        {
            return;
        }
        //
   
        //新建
        Bitmap  bmap= new Bitmap(pictureBox1.Size.Width, pictureBox1.Size.Height);
        Graphics g = Graphics.FromImage(bmap);
        g.FillRectangle(new SolidBrush(Color.White), 0, 0, bmap.Width, bmap.Height);
        g.Dispose();
        tool.targetGraphics.DrawImage(bmap,0,0);
        tool.OriginalImage = bmap;
        bmap.Dispose();
    }
   

Point9–打开文件

打开之前要提示是否保存文件

        OpenFileDialog openFile = new OpenFileDialog();
        openFile.FileName = "";
        openFile.Filter = "JPG|*.jpg;*.jpeg;*.jpe;*.jfif|GIF|*.gif|PNG|*.png|TIF|*.tif;*.tiff|ICO|*.ico|所有文件|*.*";
        if (openFile.ShowDialog() == DialogResult.OK)//文件夹显示ok（成功）
        {
            if(openFile.FileName!="")
            {

               //插入是否保存代码

               Bitmap bitmap = new Bitmap(openFile.FileName);//从指定的文件初始化bitmap
                pictureBox1.Size = bitmap.Size;//调整绘图区大小为图片大小
                pictureBox3.Location = new Point(pictureBox1.Width, pictureBox1.Height + pictureBox1.Location.Y);
                //改变那个小角角的大小
                Bitmap bm = new Bitmap(pictureBox1.Width, pictureBox1.Height);
                Graphics g = Graphics.FromImage(bm);
                g.FillRectangle(new SolidBrush(Color.White), new Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height));
                g.DrawImage(bitmap, 0, 0);
                g.Dispose();

                tool.targetGraphics = pictureBox1.CreateGraphics();
                tool.targetGraphics.DrawImage(bm, 0, 0);
                tool.OriginalImage = bm;
                bitmap.Dispose();
                bm.Dispose();
                sFilename = openFile.FileName;
                openFile.Dispose();
          
            }
        }
    }

Point10–清除

方法：绘制一个和画板一样大小的白色矩形，注意要更新原始画布和中间画布

    private void 清除ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        Bitmap newpic = new Bitmap(pictureBox1.Width,  pictureBox1.Height);
        Graphics g = Graphics.FromImage(newpic);
        g.FillRectangle(new SolidBrush(Color.White), 0, 0,pictureBox1.Width, pictureBox1.Height);
        g.Dispose();
        g = pictureBox1.CreateGraphics();
        g.DrawImage(newpic, 0, 0);
        g.Dispose();
        tool.OriginalImage = newpic;
    }

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Point11–退出

点击Form右上角的关闭角标时调用Form1_FormClosing方法
点击菜单项的关闭选项时用this.close()
关闭前要提示是否保存

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Point12–改变画板大小

改变画板大小通过画板右下角的一个小pictruebox(pb)实现。移动pb改变pb的位置，根据pb的相对于父容器的位置（即location）及画板的location得到画板的大小，改变画板大小后要改变初始画布和中间画布的大小，并将画布重新贴在画板上才能显示图案。

      private bool isResize = false;

    private void pictureBox3_MouseDown(object sender, MouseEventArgs e)
    {
        isResize = true;
    }

    private void pictureBox3_MouseMove(object sender, MouseEventArgs e)
    {
        if (isResize)
        {
            pictureBox3.Location = new Point(pictureBox3.Location.X + e.X, pictureBox3.Location.Y + e.Y);
        }
    }

    private void pictureBox3_MouseUp(object sender, MouseEventArgs e)
    {
        isResize = false;
        pictureBox1.Size = new Size(pictureBox3.Location.X-pictureBox1.Location.X, pictureBox3.Location.Y-pictureBox1.Location.Y);//改变大小

        tool.targetGraphics = pictureBox1.CreateGraphics();//再次设置
        Bitmap newBitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);
        Graphics tempGraphic = Graphics.FromImage(newBitmap);
        tempGraphic.FillRectangle(new SolidBrush(Color.White), 0, 0, pictureBox1.Width, pictureBox1.Height);//创建一张新的临时画纸
        tempGraphic.DrawImage(tool.OriginalImage, 0, 0);//将original画在上面
        tempGraphic.Dispose();

     //   graphics = pictureBox1.CreateGraphics();
        //tempGraphic =pictureBox1.CreateGraphics();
        //tempGraphic.DrawImage(newBitmap, 0, 0);
        //tempGraphic.Dispose();
      //  tool.targetGraphics.DrawImage(newBitmap, 0, 0);//--为什么不能重绘绘图板
        tool.OriginalImage = newBitmap;
        newBitmap.Dispose();

    }

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知识点1——关于按钮图片的方法

右击解决方案里的项目->进入属性->找到左侧的资源->将图像导入其中->找到按钮的image属性导入图片

知识点2——设置坐标图标

进入该项目的项目文件夹->进入bin文件夹->进入debug文件夹->在debug文件夹中创建一个文件夹存放.ico或者.cur图片
相应代码如下：

pictureBox1.Cursor = new Cursor(Application.StartupPath + @"\img\pen.ico");

知识点3——绘图板重绘

在改变绘图板的大小，或者绘图板被覆盖之后要调用重绘绘图板方法才能显示图像

      private void pictureBox1_Paint(object sender, PaintEventArgs e)
    {
        Graphics g = e.Graphics;
        g.DrawImage(tool.OriginalImage, 0, 0);
    }