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Closed 10 years ago.
I am trying to emulate some C++ code in C#. I am not familiar with the intricate workings of C++ and don't quite understand how to implement this code in C#.
Could someone please explain what the functions are doing and what their output would be in ASCII? In particular, I do not understand what the "memcpy" method is doing the way this code is written.
//example values
str = "<Request Type="Query" Version="1.0"></Request>"
uintcrc = getCrc(str, strlen(str));
//code i don't understand
//create a byte array with a null terminator?
memset(strQueryBuffer, '\0', sizeof(str));
//print the values into the byte array
sprintf(strQueryBuffer, "%c%s%c", COMM_STX, str, COMM_ETX);
//append the uintcrc to the end of the byte array?
memcpy(strQueryBuffer + strlen(strQueryBuffer), &uintcrc, sizeof(uintcrc));
it does nothing else than
strQueryBuffer = COMM_STX + "<Request Type='Query' Version="1.0"></Request>" + COMM_ETX + Encoding.Ascii.GetString(BitConverter.GetBytes(uintcrc));
if you have a binary system and want to send the complete information binary, you can also write
var str = "<Request Type='Query' Version="1.0"></Request>";
byte[] Data = (new [] { COMM_STX }).Concat(Encoding.Ascii.GetBytes(str)).Concat(new [] { COMM_ETX }).Concat(BitConverter.GetBytes(uintcrc)).ToArray();
strQueryBuffer + strlen(strQueryBuffer)
is same as
&strQueryBuffer[strlen(strQueryBuffer)]
so it append binary value of crc to the end of strQueryBuffer
Related
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Closed 9 years ago.
What are the library that use C# 4.0 dynamic as an essential part of it?
The most powerful uses of dynamic are evil incarnate and should never be used near production code.
For example:
var sql = SqlBuilder.MyDatabase
* "SELECT * FROM MyTable WHERE UserName = " + userName;
User result = sql;
dynamic could be used to turn userName into a parameter and turn the last line into an ExecuteReader() call.
Inspired by Jon Skeet
Another example:
var _ = RestClient.Builder;
var endpoint = _.https/_.api.stackexchange.com/2.1/_.answers
var results = endpoint(sort: "activity", order: "desc", site: "stackoverflow");
// Returns https://api.stackexchange.com/2.1/answers?order=desc&sort=activity&site=stackoverflow as dynamic JSON
The _ is needed to allow arbitrary identifiers.
You could get rid of the _ using expression trees:
var endpoint = RestClient.Build((https, api, answers) =>
https/api.stackexchange.com/2.1/answers
);
This uses parameter names to allow arbitrary identifiers.
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Closed 9 years ago.
How can I remove specific text from a string?
for example I have this string:
string file = "43 , 2000-12-12 003203";
I need to remove the text after the comma, including comma, so I can have as a final result:
string file = "43";
thank you,
string file = "43 , 2000-12-12 003203";
string number = file.Split(',')[0].Trim();
You can do this:
string output = file.Substring(0, file.IndexOf(',')).Trim();
However, that might fail if the string doesn't contain a comma. To be safer:
int index = file.IndexOf(',');
string output = index > 0 ? file.Substring(0, index).Trim() : file;
You can also use Split as others have suggested, but this overload would provide better performance, since it stops evaluating the string after the first comma is found:
string output = file.Split(new[] { ',' }, 2)[0].Trim();
Possibly by using Split?
file.Split(',')[0].Trim();
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Closed 9 years ago.
I have been working with the Sqlite Database on the Windows 8 App.(Sqlite for Windows Runtime)
Turkish character problem when I insert to database.
How can I fix this problem. can you help me?
Thank you very much.
Easy come.
using (var db = new SQLite.SQLiteConnection(App.DbPath))
db.Execute("Insert Into Stock (Name) Values('ŞşİıĞğ')");
i try this but result -> ÞþÝýÐð
string a = "ŞşİıĞğ";
string b = string.Empty;
byte[] utf8Bytes = Encoding.UTF8.GetBytes(a);
b= Encoding.UTF8.GetString(utf8Bytes, 0, utf8Bytes.Length);
using (var db = new SQLite.SQLiteConnection(App.DbPath))
db.Execute("Insert Into Stock (Name) Values('"+ b +"')");
Most likely the problem is that your column cannot handle UTF-16 (unicode) properly (could be client API). Safest bet is to convert to/from utf-8 on the client side then read/write to database.
System.Encoding.UTF8 has all the magic.
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Closed 10 years ago.
In C# how can I open the text file , search for string "mystring" and if string is there then set variable Vara = 1 else Vara= 0 .
Thanks in advance
Quick & dirty using System.IO.File.ReadAllText:
int Vara = File.ReadAllText(path).Contains("mystring") ? 1 : 0;
won't do all your exercise to leave you some fun, but here a way to start:
to get all text of a file into a string variable try this:
using System.IO;
string fileContent = File.ReadAllText(#"C:\file.txt");
then here to check if your string is inside:
bool present = fileContent.IndexOf("mystring") >= 0;
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Closed 11 years ago.
Never seen anything like this before. I'm doing a very simple DataReader value assignment.
story.Byline = _r["Byline"].ToString();
But the values of _r["Byline"].ToString() and story.Byline are different after the assignment. Here's the output from the Immediate window:
story.Byline
"Associated Press - FIRST LASTAssociated Press - FIRST LAST"
_r["Byline"].ToString()
"Associated Press - FIRST LAST<br />Associated Press - FIRST LAST"
Why is <br /> being removed?
Calling reader["x"].ToString() you actually calls x' type possibly overridden method ToString().
If you're sure that it's string, use reader.GetString(reader.GetOrdinal("x"))
Well, this is a bit embarrassing:
public string Byline
{
get { return !_elements.ContainsKey("Byline") ? "" : (string)_elements["Byline"]; }
set
{
string _buf = Functions.StripTags(value);
_elements["Byline"] = _buf;
}
}
Incorrect assumptions FTL. Can this question be deleted?