无法遍历文档字符串

Question

I feel I am missing something here and I was hoping someone can point me in the right direction, as I have been unable to find the answer.

I have an application that look through a document and when a value is found it prompts the user to replace this value with something else.The issue I have is; say the document has 6 of the same value which we will use $ it will only update the first value and then move on.

Document example:

    one $
    two  $
    three $
    four $
    five $

Now I understand that a string is immutable but I would have thought there is a way to loop through the information, My current code is as below;

DirectoryInfo di = new DirectoryInfo(scriptLocation);
FileInfo[] rgFiles = di.GetFiles("*.txt");
foreach (FileInfo fi in rgFiles)
{
    FileInfo fileInfo = new FileInfo(fi.FullName);
    string script = fileInfo.OpenText().ReadToEnd();
    int dollarIndex = script.IndexOf("$");
    string nextTenChars = script.Substring(dollarIndex - 17, 17);
    string promptValue = CreateInput.ShowDialog(nextTenChars, "Input");
    script = script.Replace("$", promptValue);
}

Answer 1

it will only update the first value and then move on.

The reason for that is that IndexOf returns the index of the first occurence in the string. Since you have loaded the entire file as one string this manifests as a problem in your code.

But if as you say:

They will be 17 character in the proper documents and yeah the test will be line by line

Then I would suggest to use System.IO.File.ReadAllLines to read the file. It will return a string[] and at each position is a line. So you can loop through this array and use your code

DirectoryInfo di = new DirectoryInfo(scriptLocation);
FileInfo[] rgFiles = di.GetFiles("*.txt");
foreach (FileInfo fi in rgFiles)
{
    string [] alllines = System.IO.File.ReadAllLines(fi.FullName);

    for (int i = 0; i < alllines.Length; i++)
    {
        if(alllines[i].Contains("$"))
        {
            // prompt
            int dollarIndex = alllines[i].IndexOf("$");
            string nextTenChars = alllines[i].Substring(dollarIndex - 17, 17);
            string promptValue = CreateInput.ShowDialog(nextTenChars, "Input");         
            alllines[i] = alllines[i].Replace("$", promptValue) ;
        }
    }
}

if the entire line consits only of the 17 chars plus the dollar sign you could simply drop the lines that handle this and proompt the user directly with the entire line for a replace

To write the file back use simple the File.WriteAllLines method

Answer 2

String.IndexOf Method

Reports the zero-based index of the first occurrence of a specified Unicode character or string within this instance.

So after first replace your loop is going to next file rather then looking further in the same file.

You can use another loop till the end of document.

Answer 3

Using your code and a Split method:

DirectoryInfo di = new DirectoryInfo(scriptLocation);
FileInfo[] rgFiles = di.GetFiles("*.txt");
foreach (FileInfo fi in rgFiles)
{
    FileInfo fileInfo = new FileInfo(fi.FullName);
    string script = fileInfo.OpenText().ReadToEnd();
    var values = script.Split('$');
    script = "";
    foreach (var value in values)
    {
        string promptValue = CreateInput.ShowDialog(value, "Input");
        script += promptValue;
    }
}