how to do string manipulation in C#

[azae]

hi all,

the last posting have solved by myself..

 

Now I am advancing to build program on smart device (pocket PC).

Function I want to do now is write to text file again.

 

Can I really declare my text file like this?

string fileName = "c:\\delivery.txt";
System.IO.StreamWriter writer = new System.IO.StreamWriter(fileName,True);

 

OK..

I been trying to find out the String manipulation too...

Such in VB 6 there is Mid(0,hhh)

to limit the string size.

But How to do in C#?

[Wile]

On your first question:

That declaration seems right. It should open the c:\delivery.txt file for append. You can use the writer object to send text to it.

 

On the second. Look into the String object.

Instead of Mid(<start>, <length>), you can now use SubString:

String myString = "blabla";

String subString = myString.SubString(2, 2);

 

subString would contain "ab"

 

The String object has quite a few more handy methods ;).

[azae]

Sorry its misconverzation there...

 

Sorry Wile.. what I really mean in string manipulation is actually string modifier....

 

I programming c.. we write

printf("%6d, 123");

so the output will be indent for 6 space to fit 123

I want to know how do we do that in C#.

Books I have here does not mention about this...

 

And the second thing is, is it the file system for pocket pc is the same as desktop pc?

I tried to run on emulator which include in VS.NET.

The program cause run time error.

[Wile]

I can't help you with the pocket pc filesystem, except saying that my pocket pc doesnt even have a C-root (c:\) so it is probably quite a bit different.

 

 

For printf/sprintf formatting thingies, there is String.Format (this is a static method, so use it on the String class, not on an object).

 

This uses { and } instead of the '%'. Your code would be something like String.Format("{0:6}", 123);

 

Quick copy & paste of a part of MSDN library about the format method gives another example:

  Quote

If the value of format is, "Brad's dog has {0,-8:G} fleas.", arg[0]is an Int16 with the value 42, (and in this example, underscores represent padding spaces) then the return value will be:

 

"Brad's dog has 42______ fleas."

[twistedm1nd]

StreamWriter and StreamWriter are supported by the compact framework. From what I gather about the Pocket PC is that there is no C:\. To create a directory in the main \(root folder or My device folder equivalent to C:\ on yer PC) you'd say

StreamWriter tw = new StreamWriter("\\myfile.txt");

 

to create a file in My documents you'd say

StreamWriter tw = new StreamWriter("\\My Document\\mydoc.txt");

Edited February 3, 2005 by Iceplug