Things You'll Need:
- Microsoft Visual C# 2008 Express (free)
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Step 1
Note: This article assumes you have installed Microsoft Visual C# 2008 Express Edition. You may download it for free from here: http://www.microsoft.com/express/download/
Open Microsoft Visual C#. Click on "Project..." to the right of Create in the Recent Projects area of the Start Page.
The New Project window will open. Click on "Windows Forms Application", enter a Name, and click OK.
By default, the only form in the project will be called "Form1" and you will be in Design mode for that form. -
Step 2
Hover over the Toolbox on the left side of the screen and the Toolbox will automatically expand. Click and drag a Button control, under the Common Controls category, onto the form.
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Step 3
Double click the button and you will now be in the code window for Form1. The method for the button click will already be created.
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Step 4
Add "using System.IO;" just beneath "using System.Windows.Forms;". This namespace contains the StreamWriter object that we will be using to write out to the file.
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Step 5
Before we write the code to read from a file, we need to make the file. Place a text file named "TestFile.txt" in C:\. I put the following lines in my file:
C# is the bomb!
Sorry Java. :( -
Step 6
In the button1_Click method, place the following code:
try{
using(StreamReader MyStreamReader = new StreamReader("C:\\TestFile.txt")){
String MyLine;
while ((MyLine = MyStreamReader.ReadLine()) != null)
{
MessageBox.Show(MyLine);
}
}
}
catch(Exception MyError){
MessageBox.Show("Error reading file: "+ MyError.Message);
}
The try/catch statements will capture any error that occurs and will pop-up a MessageBox with the error displayed.
Our instance of the StreamReader is called MyStreamReader and is contained within a "using" clause. This will cause the memory used by MyStreamReader to be disposed of effectively.
MyStreamReader.ReadLine() will read in a line from the text file and store that in the string MyLine. If MyStreamReader.ReadLine()reaches the end of the file, it will return null. The while loop tests the that the value MyLine is not null on each pass of the loop. If Myline is not null, MyLine is displayed in a MessageBox. If Myline is null, the while loop will terminate.
Note that when we created our instance of the StreamReader, we had to use double backslashes for the path: "C:\\TestFile.txt". This is due to a single slash being a special character in a string. -
Step 7
Go up to the toolbar and run the program by clicking on the Start Debugging (f5) play button.
NOTE: If you got any kind of error after clicking the play button, you probably made a syntax error when typing the code. Reread the code until you find and correct the error and try again. -
Step 8
The form will take a moment and then pop up. Awesome!
