Need help with String.Format arguments

Question

I am trying to implement the ability for users to specify which string fields will appear in an invoice richtextbox and what order they will appear in the line of text. This string is an invoice line and there can be multiple lines so the formatting needs to also specify field widths for alignment.

I am trying to use String.Format so I can pass the filed position and format specifiers (as shown below) but am just totally stuck as how to pass the field name parameters since the order and number of fields will vary.

I have 10 fields so the user can select from 1 to 10 of the fields and then specify the order they want them to appear.

The end result String.Format call needs to look something like this.

// format specifer info: {field_number, width/alignment}

String.Format("{0,-10}, {1,-35}{2,-10}", sDate, sDesc, sPrice);
or this...
String.Format("{0,-10}, {1,-10}{2,-35}", sDate, sPrice, sDesc);
or this
String.Format("{0,-10}, {1,-10}{2,-35}{3,-15}{4,-10}", sDate, sPrice, sDesc, sSalesman, sAcct);
or any other combination of fields and field order.

I have the code to build the formattting specifier all done, but....
I am at a loss on how to build and pass the list of my string variable names.

I bet this is something so stupid, but I give up. I have been overthinking this.

I appreciate any help, assistance, etc....

Sam Hobbs · Answer

Yes  format individual field and then concatenate  is what I was trying to say from the beginning.

Bill Az · Answer

I think I got it now. I got hung up on having to use the format string parameter in String.Format () to specify the order AND width of multiple fields (IE: {1-10}{2-25}) when it would be much easier to just format individual field and then concatenate. So I have a listbox with the field names that the user selected in the order they specified.... For Example: listbox items/order Date Desc Price private string CreateInvoiceLine( string sDate string sTime string sPrice string sServiceDesc string sServiceLevel string sDriver string sComment) { string sConcatenatedInvoiceFields = |; string sFieldName; for (int nIdx = 0; nIdx { sFieldName = listBoxInvoiceItems.Items[nIdx].ToString(); Debug.WriteLine( -  + sFieldName); if (sFieldName == Date) { // All we are formatting is the width/alignment // Field # is irrelevent ?? // Append the formatted field // loop should put fields in proper order sConcatenatedInvoiceFields += String.Format({0-15}| sDate); } else if (sFieldName == Time) { sConcatenatedInvoiceFields += String.Format({0-12}| sTime); } else if (sFieldName == Price) { sConcatenatedInvoiceFields += String.Format({0-10}| sPrice); } else if (sFieldName == Service Description) { sConcatenatedInvoiceFields += String.Format({0-25}| sServiceDesc); } else if (sFieldName == Service Level) { sConcatenatedInvoiceFields += String.Format({0-25}| sServiceLevel); } else if (sFieldName == Driver) { sConcatenatedInvoiceFields += String.Format({0-10}| sDriver); } else if (sFieldName == Comment) { sConcatenatedInvoiceFields += String.Format({0-25}| sComment); } } sConcatenatedInvoiceFields += 
; // End the line Debug.WriteLine(sConcatenatedInvoiceFields); return sConcatenatedInvoiceFields; } Sample runtime data: |12-17-2007 | 75.00 |service description | |12-23-2007 | 50.00 |test test test |
 I appreciate your assistance.

Sam Hobbs · Answer

We can help you better if you explain better what you need. You can format each of the 10 or so items separately then put them together in whatever order that is needed. I might be able to help you better but you I do not see an answer to the question: will there always be the same fields except just in varying orders; in other words if there are 10 fields will there always be the same 10 fields except in a different order?

Bill Az · Answer

Niki & Sam H Thanks for your posts. Sam - I tried to tellyou everything. I guess I tried a single String.Format() call because that is all I could figure out. I am not sure how you are saying to use multiple calls. I am trying to avoid hard coding each possible parameter scenario (there are 100 combinations). Niki - How would I call your example? thanks

Sam Hobbs · Answer

You seem to want to do all fields in one Format but most programmers would not. Is there something you are not telling us that requires this to be done all in one Format? If you can use separate Format functions for each field then that can be done using very many ways.

Nilanka Dharmadasa · Answer

Hi friend Why do you try to build a dynamic String.Fomrat when you can keep it fixed and pass the parameters dynamiclly. You write a function like this. As you have said 10 is the max number of parametrs. So you can create a string array and assign variables dynamically depending upon your logic. If you have less number of parameters than 10 then you can pass empty strings. private string GetText( string [] para) { if ((para == null ) || (para.Length return  ; //Here para is an array with 10 items string mystring = String .Format( {0}{1}{2}{3}{4}{5}{6}{7}{8}{9}  para[0]para[1]para[2]para[3]para[4]para[5]para[6]para[7]para[8]para[9]); return mystring ; } string[] para = new string [10]; para[0] = ....; para[1] = ....; para[2] = ....; ....... Then you can call string finatext = GetText(para); If my answer helps you accept my answer. Otherwise let me know.

Bill Az · Answer

Here is a clarification. All I am trying to figure out is how to dynamically build the String.Format function call. Also....the number of parameters being passed to String.Format() will vary - anywhere from 1 to 10 and their order is also unknown until runtime. The 1st parameter is the format string which is easy - it is just a string and I have the code for that working. The part I am wrestling with is how to dynamically list the remaining parameters which specify the strings to be passed to String.Format(). I tried creating a string and added the variable names in double quotes separated by commas to mimic the function call but could not get this to work (see below). The issue for me is finding out a way to dynamic way to pass parameters that are unknown until runtime. I guess I have never run into something like this before. I can't imagine that it hasn't been done and I don't seem to be thinking straight today. sInvoiceFieldList = \sDate\sPrice\sDesc\sComment\ My hope was that this string could be used in place of an actual list of arguments/parameters. Here is more code. sInvoiceFieldFormat = {0-15}{1-10}{2-25}{3-25}
 string.Format(sInvoiceFieldFormat sInvoiceFieldList); Unhandled exception of type 'System.FormatException' occurred in mscorlib.dll Additional information: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.

Sam Hobbs · Answer

I am not sure I understand. Are you saying you have some fields (10 or so) each with a specified format and you just want to know how to process them in a specified order? Perhaps you can create an array of instances of an object representing each item and then the order could consist of another array of indexes. The order in the array of each index of the item in the item list could determine the formatted order. For example: 1 field1 formatfor1 2 field2 formatfor2 . . . 10 field10 formatfor10 Order array: 5 4 6 3 1 2 10 9 7 8