使用datagridview中的值绘制线条 [英] Drawing lines by using values from a datagridview

问题描述

我有一个Windows应用程序。 [ ^ ]



当我点击Calculate时，我会使用这些文本框进行一些计算。

通过这些计算，我获得了一些值，并将它们写在datagridview [ ^ ]



此时，我需要画画一些行使用这些值基本上是我的点的坐标..



有些人告诉我创建一个图片框并创建一个绘画事件。

因此我尝试了这个;

I have a windows application. [^]

When I click on Calculate, I make some calculations using those textboxes.
with those calculations, I obtain some values and write them on a datagridview [^]

At this point, I need to draw some lines using those values which are basically coordinates of my points..

Some people told me to create a picturebox and create a paint event.
Therefore I tried this;

Pen myPen = new Pen(Color.Black);

        private void pictureBoxDraw_Paint(object sender, PaintEventArgs e)
        {
            myPen.Width = 2;
            if (binary > 0)
            {
                Point point1 = new Point(10, 20);
                Point point2 = new Point(10, 40);
                e.Graphics.DrawLine(myPen, point1, point2);
            }
            else
            {
            }
        }
      
        private void buttonDraw_Click_1(object sender, EventArgs e)
        {
            binary = 1;
            pictureBoxDraw.Invalidate();
            
        }

        private void buttoncleardraw_Click(object sender, EventArgs e)
        {
            binary = 0;
            pictureBoxDraw.Invalidate();
        }

当我改变时

When I change

Point point1 = new Point(10, 20);

到

Point point1 = new Point(Convert.ToInt32(dataGridViewCrestGeo.Rows[0].Cells[0].Value), Convert.ToInt32(dataGridViewCrestGeo.Rows[0].Cells[0].Value));

我收到一条错误消息，如 [ ^ ]

I当我点击绘图按钮时，需要找到一种绘制这些线条的方法。



我是土木工程师，所有这些对我来说都很复杂。我将不胜感激任何帮助。谢谢。



我的尝试：

I obtain an error message like this [^]
I need to find a way to draw these lines when I click on the Draw button.

I am a civil engineer and all these things are really complicated for me. I would appreciate any kind of help. Thanks.

What I have tried:

Pen myPen = new Pen(Color.Black);

        private void pictureBoxDraw_Paint(object sender, PaintEventArgs e)
        {
            myPen.Width = 2;
            if (binary > 0)
            {
                Point point1 = new Point(Convert.ToInt32(dataGridViewCrestGeo.Rows[0].Cells[0].Value), Convert.ToInt32(dataGridViewCrestGeo.Rows[0].Cells[0].Value));
                Point point2 = new Point(10, 40);
                e.Graphics.DrawLine(myPen, point1, point2);
            }
            else
            {
            }
        }
      
        private void buttonDraw_Click_1(object sender, EventArgs e)
        {
            binary = 1;
            pictureBoxDraw.Invalidate();
            
        }

        private void buttoncleardraw_Click(object sender, EventArgs e)
        {
            binary = 0;
            pictureBoxDraw.Invalidate();
        }

推荐答案

查看错误消息 - 它不是在抱怨抽奖，而是关于数据的格式你正在尝试转换为数字。这就是FormatException的用途！



最有可能的是，特定单元格中的值不是你想象的那样：它不是整数！

因此将值提取到变量中：

Look at the error message - it's not complaining about the draw, but about the format of the data you are trying to convert to a number. That's what a FormatException is there for!

Most likely, the value in that specific cell is not what you think it is: it's not an integer!
So extract the value into a variable:

object data = dataGridViewCrestGeo.Rows[0].Cells[0].Value;

在行上放置一个断点，并在调试器中运行您的代码。当它到达那里时，它会停止。单步行，并准确查看数据中的内容 - 它会告诉您正在查看的数据类型，这应该告诉您为何无法转换为整数。

我们不能为您做到这一点 - 我们无法访问您的DataGridView或其包含的数据！

Put a breakpoint on the line, and run your code in the debugger. when it gets there, it will stop. Single step the line, and look at exactly what is in data - it will tell you what kind of data you are looking at, and that should tell you why it fails conversion to an integer.
We can't do that for you - we don't have any access to your DataGridView or the data it contains!

好的，我设法以某种方式划清界限。我将离开我的解决方案以防其他人需要它。

Ok, somehow I managed to draw the lines. I'm leaving my solution here in case of anyone else needs it :)

Pen myPen = new Pen(Color.Black);

        private void pictureBoxDraw_Paint(object sender, PaintEventArgs e)
        {
            myPen.Width = 2;
            if (binary > 0)
            {

                float distance1 = float.Parse(dataGridViewCrestGeo.Rows[0].Cells[0].Value.ToString()) * -10;
                float distance2 = float.Parse(dataGridViewCrestGeo.Rows[1].Cells[0].Value.ToString()) * -10;

                float elevation1 = float.Parse(dataGridViewCrestGeo.Rows[0].Cells[1].Value.ToString()) * -10;
                float elevation2 = float.Parse(dataGridViewCrestGeo.Rows[1].Cells[1].Value.ToString()) * -10;
                

                e.Graphics.DrawLine(myPen, distance1, elevation1, distance2, elevation2);
                
             
            }
            else
            {
            }
        }
      
        private void buttonDraw_Click_1(object sender, EventArgs e)
        {
            binary = 1;
            pictureBoxDraw.Invalidate();
            
        }

        private void buttoncleardraw_Click(object sender, EventArgs e)
        {
            binary = 0;
            pictureBoxDraw.Invalidate();
        }

这篇关于使用datagridview中的值绘制线条的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！