Arrays in C#

[blaze007]

I have a text file containing the following content:

0 12
1 15
2 6
3 4
4 3
5 6
6 12
7 8
8 8
9 9
10 13

There are no spaces between two rows but there is a space between two numbers. I want to read these integers from a txt file and save the two columns into two different arrays in C# and then i have to display array values.Can anyone help?

[ddanbe]

You could start by reading this on how to read a string from a file.
Then read about the string Split member here

[tinstaafl]

You could use a third array to hold the lines of strings. For each line in the string array .Split()[0] gets parsed to an int and put in array1, and .Split()[1] gets parsed as an int and put into array2.

Here's a link to the C# Programming Guide

When you've read the resource material and attempted some code let us know when you have specific code that doesn't work.

[JOSheaIV]

Read in the values from the fiile, using what ddanbe gave you to get you started.

Now can I ask you this. I assume the numbers are on one line. The file you are trying to read in, how exactly does it look? I know a great way to split strings up between arrays but need to see what you are working with (String parsing is one of my specialties)

Hope to hear back soon

[blaze007]

Each line has two numbers which are integers and no decimal numbers.the first column specifies the x-coordinate and other represents the y-coordinate.there is space between two numbers but there is no space between two lines.i have written the following code but it raises an error saying "Input string was not in a correct format".Can u help me with the code?

private void btnrecog_Click(object sender, RoutedEventArgs e)
        {
            List<int> column0  = new List<int>(), column1 = new List<int>();

            using (Stream stream = File.Open("abcdaslak.txt", FileMode.Open))
            using (TextReader sr = new StreamReader(stream, Encoding.UTF8))
                    {
                        string line;
                        while ((line = sr.ReadLine()) != null)
                                     {
                                        string[] arr = line.Split(' ');
                                        column0.Add(Int32.Parse(arr[0]));
                                        column1.Add(Int32.Parse(arr[1]));
                                     }
                    }

            for (int i = 0; i < column0.Count; i++)
            {
                Console.WriteLine(column0[i]);
                Console.WriteLine(column1[i]);
            }


        }

[ddanbe]

Tried your code, and had no problem.
Just wondering why you are using Console.WriteLine. If it is for testing, I debug or I use MessageBox.Show.

[tinstaafl]

You better check your text file, when I run your code using the numbers in your original post, it works fine. Except that I put the numbers into a listbox, since you can't normally show a console in a form app. If you still get an error try this:

        private void button1_Click(object sender, EventArgs e)
        {
            List<int> column0 = new List<int>(), column1 = new List<int>();
            foreach (string line in File.ReadAllLines(@"C:\abcdaslak.txt"))
            {

                column0.Add(GetInt(line.Split()[0]));
                column1.Add(GetInt(line.Split()[1]));
            }
            for (int i = 0; i < column0.Count; i++)
            {
                listBox1.Items.Add(column0[i] + " " + column1[i]);
            }            

        }
        private Int32 GetInt(string TempString)
        {
            Int32 tempint = 0;
            bool GoodParse = Int32.TryParse(TempString, out tempint);
            if (GoodParse)
            {
                return tempint;
            }
            else
            {
                MessageBox.Show(TempString);
                return -1;
            }
        }

Any string that can't be parsed will be shown in a messagebox and the value displayed in the listbox will be -1

[blaze007]

@tinstaafl thank you so much.ur code works fine but still can't figure out whats the problem with my code.i think we cant use console with WPF applications

[Ketsuekiame]

No, there is no visible console window for WPF applications. You would need to define a control on your display window and place the output there.

Is there any particular reason you're using WPF for something this simple? It's not really appropriate to the task.

[blaze007]

actually i'm working on a project and aim is to develop an application that can recognize and redraw circuits which are drawn with a stylus pen on a tablet PC.So the above code is a part of recognition.i need to find the slope of the line drawn on the inkcanvas.if its slope is zero then we can recognize it as a wire.

so what i'm doing is putting the x and y coordinate in separate lists and then i can find the slope using

for (int i=0; i<=column1.Count - 2;i++)
{
  float slope = (column1[i+1] - column1[i])/(column0[i+1] - column0[i])
}

Thats the plan! if u have any new idea do share.

[ddanbe]

If(as I guess) column1 reprsents the Y-coordinate and column0 the X-coordinate, why don't you call them as such? A column can be anything a coordinate is a coordinate.
Why are you using a for loop? The slope will be calculated with the last point.

[blaze007]

yes you are right about the slope but then it would be difficult to differentiate between a wire and a resistance. A wire( straight line) will have same slope throughout unlike resistor.thus i need to calculate slope at every point

[ddanbe]

I'm a bit older then you I guess and also a bit shaky sometimes. So by moments my strait line drawings would also have a slope != zero. How you are going to detect the difference?