我出现错误“方法'getValidString'的重载不带参数”。 这是什么意思，我该如何解决？

Question

this is for my college course and the deadline is in 2 days and i still have to finish the program test the code and also evaluate before then.

Below is the routine code.

public static string getValidString(string prompt, int maxLength)
{
    bool valid = false; 
    //The paramter valid is set as a boolean and is set to false. 
    //It is set as a boolean because it is a small data type and 
    //only needs to have true or false
    string tempData = "";
    do // Do while loop is repetition and carries on doing it until the condition becomes true
    {
        Console.Write(prompt + " ?");
        tempData = Console.ReadLine();
        if (tempData == "")
            displayMessage("You have not entered any data, please try again");
        else if (tempData.Length < 3)
            displayMessage("You have not entered text longer than 3, please try again");
        else if (tempData.Any(c => char.IsDigit(c)))
            displayMessage("You have not entered text, please try again");
        else if (tempData.Length > maxLength)
            displayMessage("Name too long it must be 20 or less, please try again");
        else
            valid = true;
    }
    while (valid == false);
    return tempData;
}

And the code in my program which has the error attached is below. How do I fix this? Thank you

private void btncustCont_Click(object sender, EventArgs e)
{
    txtName.Text = custName[numCust];
    txtPhoneNumber.Text = custPhone[numCust];
    string sError = "";
    sError = routine.getValidString("Customer Name", txtName.Text, 3, 30);
    sError += routine.getValidString("Customer Phone Number", txtPhoneNumber.Text, 3, 30);
    if (sError != "")
    MessageBox.Show(sError, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

    if (sError == "")
        grpPrint.Enabled = true;
}

Answer 1

Your method getValidString have 2 inputs : string prompt and int maxLength

However, you're sending 2 strings and 2 ints (for a total of 4) ("Customer Name", txtName.Text, 3, 30)

Either overload getValidString to take 4 input like this

public static string getValidString(string prompt, string name, int length, int maxLength)

or send only one string and an int :

routine.getValidString("Customer Phone Number", 30);

Answer 2

Your method is defined with only two parameters public static string getValidString(string prompt, int maxLength) . But you're calling it with 4: sError = routine.getValidString("Customer Name", txtName.Text, 3, 30);

Either add the missing parameters to the getValidString: public static string getValidString(string prompt, int maxLength, int foo, int bar)

or

Or remove them from the sError line: sError = routine.getValidString("Customer Name", txtName.Text);

Answer 3

It's simply saying there is no version of getValidString which accepts the arguments you're attempting to pass it. Review the definition(s) of the method. You can do this by mousing over it. If there are overloads there will be little arrows to cycle through them. The info will tell which types, and in what order they're accepted.

Oh I just noticed your definition is listed above. As you can see it only accepts a string and an int. You're trying to call it with the argument list; string, string, int, int. You need to change the method to accept all of those arguments or change the calling code to call it with a string and an int.

Answer 4

Your function signature is defined as the following:

public static string getValidString(string prompt, int maxLength) { /* CODE */ }

It is taking 2 arguments: prompt (a string ) and maxLength (an int ).

When you are calling it later, you are passing four arguments to it:

sError = routine.getValidString("Customer Name", txtName.Text, 3, 30);

Since there is no signature for getValidString() that matches the arguments you are passing ( string , string , int , int ), the C# compiler is rising an error.