Question

我有一个pictureBox1绘画事件。在paint事件中我正在写一些文本文件：

    private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
            {
                SolidBrush brush;
                Pen p=null;
               Point connectionPointStart;
               Point connectionPointEnd;
               Graphics g = e.Graphics;
               g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;

                   brush = new SolidBrush(Color.Red);
                   p = new Pen(brush);
                   for (int idx = 0; idx < wireObject1._point_X.Count; ++idx)
                   {
                       Point dPoint = new Point((int)wireObject1._point_X[idx], (int)wireObject1._point_Y[idx]);
                       dPoint.X = dPoint.X - 5; // was - 2
                       dPoint.Y = dPoint.Y - 5; // was - 2
                       Rectangle rect = new Rectangle(dPoint, new Size(10, 10));
                       g.FillEllipse(brush, rect);

                       // g.FillEllipse(brush, rect);
                   }

                   for (int i = 0; i < wireObject1._connectionstart.Count; i++)
                   {

                       int startIndex = wireObject1._connectionstart[i];
                       int endIndex = wireObject1._connectionend[i];



                       connectionPointStart = new Point((int)wireObject1._point_X[startIndex], (int)wireObject1._point_Y[startIndex]);
                       connectionPointEnd = new Point((int)wireObject1._point_X[endIndex], (int)wireObject1._point_Y[endIndex]);
                       p.Width = 4;
                       g.DrawLine(p, connectionPointStart, connectionPointEnd);
                       moveCounter++;
                       textBox1.Text = moveCounter.ToString();
                       if (moveCounter > 10)
                       {
                           w.WriteLine("Number Of Moves ===>   " + moveCounter);
                       }
                   }

            }

In the bottom i have a w.WriteLine....
In the top of Form1 i did StreamWriter w;
In the constructor i did: w = new StreamWriter(@"d:\test.txt");

In the pictureBox1 mouse up event im doing w.Close();

    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
            {

                if (mouseMove == true)
                {
                    Point NewPoint = e.Location;
                    wireObject1._point_X[(int)selectedIndex] = NewPoint.X;
                    wireObject1._point_Y[(int)selectedIndex] = NewPoint.Y;
                    mouseMove = false;
                    if (moveCounter == 0)
                    {
                    }
                    else
                    {
                        w.Close();
                    }
                    WireObjectCoordinatesCloneFrame();

                }

            }

所以我将鼠标的记录移动到文件中，变量moveCounter的信息是int的类型。

问题是当我制作鼠标按钮事件并关闭图片框1中的文件时，我看到一个白色背景的大红色X. 它自己的文件在硬盘上是可以的，包含我想要的所有信息。

但为什么大红色x出现在pictureBox1中？如果我从paint事件中删除了w.WriteLine，那么我就不会看到大的红色x。

我该怎么做才能解决它？

Answer 1

关闭流编写器后，您仍然在尝试在paint事件中写入它。这将失败（你不能写入封闭的流），因此paint事件处理程序将抛出异常 - 导致红色X出现。

在油漆事件中执行任何IO都是非常奇怪的，说实话......你真正想要实现的目标是什么？

为什么StreamWriter在绘制事件中不能正常工作？在pictureBox中获取大红色x

1 个答案: