How to convert a SINGLE char to system string C++? - c++

Question

I'm working on a program that displays the following chars/integers in a console app.
The code that I wrote works in console app, but doesn't work in form...
I also want to display these values in my form( textBox->text).
My myfunctions.h file:
typedef struct{
char Header [23]; //the char I want to display is 23 characters long
int Version [4]; //4 characters...
char Projectname [21];
char Developer [8];
char email [16];
char Description [132];
char Unknown [1];
}PackedContent;
void BinaryReader(){
system("CLS");
PackedContent t;
fstream myFile;
myFile.open("PackedContent.opf");
if(!myFile){
cout<<"An unknown error occured! Cannot read .opf file... exiting now... \n"<<endl;
}else{
cout <<"Reading packed data content... done!\n"<<endl;
myFile.read((char *)&t, sizeof(PackedContent));
cout<<"\nHeader :" <<t.Header <<endl; // Header info [ok]
//cout<<"\nVersion :" <<t.Version <<endl; // Project Version [err]
cout<<"\nProject name:" <<t.Projectname <<endl; // Project name
cout<<"\nDeveloper name:" <<t.Developer<<endl;
cout<<"\nEmail :" <<t.email <<endl; // Developer email
cout<<"\nDescription :" <<t.Description <<endl; // Project description [ok]
cout<<"Unknown" <<t.Unknown <<endl;
}
Form:
Binary Reader.H (form)
PackedContent t;
BinaryReader();
textBox1->Text = t.Header; // doesnt work...
I've aslo tried:
textBox1->Text = Convert::ToString(t.Header); //doesn't work...

Answer 1

If your char array was null-terminated, like C-strings, you could have passed it as is to an std::string c'tor:
textBox1->Text = std::string(t.Header)
Your char array is not null terminated, so you should also provide the size, like this:
int headerSize = 1; // This variable is just for the example. Instead you can pass the size right in the function below
textBox1->Text = std::string(t.Header, headerSize)
Or:
textBox1->Text = std::string(t.Header, std::size(t.Header))

Answer 2

You have forgot about terminating zero and this is why you have problems.
If you what to store text in c-array which can have length of 23 you need char[24] (23 + 1) to include tailing zero too.
Anyway using this c-array to store text is C-style code not C++ and this should be avoided.
If you do not include terminating zero then for example this call extBox1->Text = t.Header; will try to finds it to perform conversion to String. This will lead to undefined behavior, result string will contain some trash at the end or it will end with a crash.
If your code records terminating zero in this structure, but reaches size limit, then you will have buffer overrun error.