捕获屏幕实际上没有捕获正确的区域

Question

我在 C# 中编写了一个应用程序，您可以在其中 select 一个用于拍摄屏幕截图的框，如果您在 X 轴上的 0 上方，它不会拍摄照片。我画了一张小图来说明我的意思：

红色 = 图片实际上不属于该部分黑色 = 好

我的代码如下：

#region testing

private Point start = Point.Empty;
private Point end = Point.Empty;

private void Form2_MouseDown(object sender, MouseEventArgs e)
{
    if ((e.Button & MouseButtons.Left) != 0)
    {
        start.X = e.X;
        start.Y = e.Y;
    }
}

private void Form2_MouseMove(object sender, MouseEventArgs e)
{
    Point p1;
    Point p2;
    if (((e.Button & MouseButtons.Left) != 0) && (start != Point.Empty))
    {
        using (Graphics g = this.CreateGraphics())
        {
            p1 = PointToScreen(start);
            if (end != Point.Empty)
            {
                p2 = PointToScreen(end);
                ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), 
                    Color.Black, FrameStyle.Dashed);
            }
            end.X = e.X;
            end.Y = e.Y;
            p2 = PointToScreen(end);
            ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), 
                Color.Black, FrameStyle.Dashed);
        }
    }
}

private void Form2_MouseUp(object sender, MouseEventArgs e)
{
    Point p1;
    Point p2;
    if ((end != Point.Empty) && (start != Point.Empty))
    {
        using (Graphics g = this.CreateGraphics())
        {
            p1 = PointToScreen(start);
            p2 = PointToScreen(end);
            ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), 
                Color.Black, FrameStyle.Dashed);

            int x1 = p1.X;
            int y1 = p1.Y;
            int x2 = p2.X;
            int y2 = p2.Y;
            int x = x2 - x1;
            int y = y2 - y1;

            string[] xsp;
            int rx = 0;
            string[] ysp;
            int ry = 0;
            if (x.ToString().Contains("-"))
            {
                xsp = x.ToString().Split('-');
                rx = Convert.ToInt32(xsp[1]);
            }
            else
            {
                rx = x;
            }

            if (y.ToString().Contains("-"))
            {
                ysp = y.ToString().Split('-');
                ry = Convert.ToInt32(ysp[1]);
            }
            else
            {
                ry = y;
            }

            using (Bitmap bmpScreenCapture = new Bitmap(rx, ry, g))
            {
                using (Graphics gra = Graphics.FromImage(bmpScreenCapture))
                {
                    if(x.ToString().Contains("-"))
                    {
                        gra.CopyFromScreen(x2, y1, 0, 0, bmpScreenCapture.Size, 
                            CopyPixelOperation.SourceCopy);
                    }
                    else if(!x.ToString().Contains("-"))
                    {
                        gra.CopyFromScreen(x1, y1, 0, 0, bmpScreenCapture.Size, 
                            CopyPixelOperation.SourceCopy);
                    } 
                    else if(y.ToString().Contains("-"))
                    {
                        gra.CopyFromScreen(x1, y2, 0, 0, bmpScreenCapture.Size, 
                            CopyPixelOperation.SourceCopy);
                    }
                    else if (!y.ToString().Contains("-"))
                    {
                        gra.CopyFromScreen(x1, y1, 0, 0, bmpScreenCapture.Size, 
                            CopyPixelOperation.SourceCopy);
                    }
                    else if (x.ToString().Contains("-") && y.ToString().Contains("-"))
                    {
                        gra.CopyFromScreen(x2, y2, 0, 0, bmpScreenCapture.Size, 
                            CopyPixelOperation.SourceCopy);
                    } 

                    string filename = GenerateRandomString(20) + ".png";
                    bmpScreenCapture.Save(Path.GetTempPath() + "" + filename, 
                        ImageFormat.Png);

                    ControlPaint.DrawReversibleFrame(GetRectangleForPoints
                        (new Point(0), new Point(0)), Color.Black, FrameStyle.Dashed);
                    //Upload(Path.GetTempPath() + "" + filename, filename);
                }
            }
        }
    }
    start = Point.Empty;
    end = Point.Empty;
}
private Rectangle GetRectangleForPoints(Point beginPoint, Point endPoint)
{
    int top = beginPoint.Y < endPoint.Y ? beginPoint.Y : endPoint.Y;
    int bottom = beginPoint.Y > endPoint.Y ? beginPoint.Y : endPoint.Y;
    int left = beginPoint.X < endPoint.X ? beginPoint.X : endPoint.X;
    int right = beginPoint.X > endPoint.X ? beginPoint.X : endPoint.X;

    rect = new Rectangle(left, top, (right - left), (bottom - top));
    return rect;
}
#endregion

我已尝试更正它，但没有成功。我的意思是图片仍然显示，但它不是屏幕的正确区域。

Answer 1

我开始使用不同的选择方法，这让我可以得到矩形 X 和 Y 以及尺寸。更好的解决方案:)

代码：

#region testing
    private Point start = Point.Empty;
    private Point end = Point.Empty;
    private void Form2_MouseDown(object sender, MouseEventArgs e)
    {
        if ((e.Button & MouseButtons.Left) != 0)
        {
            start.X = e.X;
            start.Y = e.Y;
        }
    }

    private void Form2_MouseMove(object sender, MouseEventArgs e)
    {
        //this.Invalidate();
        Point p1;
        Point p2;
        if (((e.Button & MouseButtons.Left) != 0) && (start != Point.Empty))
        {
            using (Graphics g = this.CreateGraphics())
            {
                g.Clear(this.BackColor);
                p1 = PointToScreen(start);
                if (end != Point.Empty)
                {
                    p2 = PointToScreen(end);
                    ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), Color.Black, FrameStyle.Dashed);
                }
                end.X = e.X;
                end.Y = e.Y;
                p2 = PointToScreen(end);
                ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), Color.Black, FrameStyle.Dashed);
            }
        }
    }

    private void Form2_MouseUp(object sender, MouseEventArgs e)
    {
        Point p1;
        Point p2;
        if ((end != Point.Empty) && (start != Point.Empty))
        {
            using (Graphics g = this.CreateGraphics())
            {
                p1 = PointToScreen(start);
                p2 = PointToScreen(end);
                ControlPaint.DrawReversibleFrame(GetRectangleForPoints(p1, p2), Color.Black, FrameStyle.Dashed);
                int x1 = p1.X;
                int y1 = p1.Y;
                int x2 = p2.X;
                int y2 = p2.Y;
                int x = x2 - x1;
                int y = y2 - y1;

                string[] xsp;
                int rx = 0;
                string[] ysp;
                int ry = 0;
                if (x.ToString().Contains("-"))
                {
                    xsp = x.ToString().Split('-');
                    rx = Convert.ToInt32(xsp[1]);
                }
                else
                {
                    rx = x;
                }
                if (y.ToString().Contains("-"))
                {
                    ysp = y.ToString().Split('-');
                    ry = Convert.ToInt32(ysp[1]);
                }
                else
                {
                    ry = y;
                }

                using (Bitmap bmpScreenCapture = new Bitmap(rect.Width, rect.Height, g))
                {
                    using (Graphics gra = Graphics.FromImage(bmpScreenCapture))
                    {
                        gra.CopyFromScreen(rect.X, rect.Y, 0, 0, bmpScreenCapture.Size, CopyPixelOperation.SourceCopy);
                        string filename = GenerateRandomString(20) + ".png";
                        bmpScreenCapture.Save(Path.GetTempPath() + "" + filename, ImageFormat.Png);
                        g.Clear(this.BackColor);
                        //Upload(Path.GetTempPath() + "" + filename, filename);
                    }
                }
            }
        }
        start = Point.Empty;
        end = Point.Empty;
    }
    private Rectangle GetRectangleForPoints(Point beginPoint, Point endPoint)
    {
        int top = beginPoint.Y < endPoint.Y ? beginPoint.Y : endPoint.Y;
        int bottom = beginPoint.Y > endPoint.Y ? beginPoint.Y : endPoint.Y;
        int left = beginPoint.X < endPoint.X ? beginPoint.X : endPoint.X;
        int right = beginPoint.X > endPoint.X ? beginPoint.X : endPoint.X;

        rect = new Rectangle(left, top, (right - left), (bottom - top));
        return rect;
    }
    #endregion

捕获屏幕实际上没有捕获正确的区域

Capturing screen not actually capturing right region

c#

screenshot

winforms