C++ Windows Forms L06 - Utlitity and Strings

Mohammad Shakermohammadshakergtr.wordpress.com

C++.NET Windows Forms Course@ZGTRShaker

C++.NET Windows Forms Course

L06-Utility

How to work with OOP in .NET

How to work with OOP in .NET

• Structure of Form class

• Adding variables – Public– Private

• Adding member functions– Procedural

• Adding classes by “ref”

• Passing parameters – % , ^

Debugging

Debugging – Break Point

Debugging

references \ declarations \ definitions

Searching in msdn

DateTime class

DateTime

DateTime

private: System::Void button1_Click(System::Object^ sender,

System::EventArgs^ e)

{

DateTime D;

D.Now;

textBox1->Text= D.Day.ToString();

};

1



{

DateTime D;

textBox1->Text= D.Day.ToString();

};

1

DateTime



{

DateTime D;

D.Now;

textBox1->Text= D.Now.Day.ToString();

};

9

DateTime Constructor

DateTime Methods

DateTime

DateTime

• Considering today is 22/10/2010, the output will be

private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e)

{

// Calculate what day of the week is 36 days from this instant

DateTime ^today= DateTime::Now;

TimeSpan duration(36, 0, 0, 0);

DateTime ^answer= today->Add(duration);

textBox1->Text= answer->ToString();

}

11/27/2010 1:49:12 AM

DateTime



{

DateTime ^Day= gcnew DateTime(2010, 10, 6);

textBox1->Text= Day->ToString();

}

10/6/2010 12:00:00 AM

DateTime date1= gcnew DateTime::Now;

DateTime date2= gcnew DateTime::UtcNow;

DateTime date3= gcnew DateTime::Today;

Utc: Coordinated Universal Time

DateTime



{


textBox1->Text= Day->ToLongTimeString();

}

12:00:00 AM



{


textBox1->Text= Day->ToLongDateString();

}

Wednesday, October 06, 2010

DateTimeprivate: System::Void button1_Click(System::Object^ sender,


{


textBox1->Text= Day->ToShortDateString();

}

10/6/2010



{


textBox1->Text= Day->ToShortTimeString();

}

12:00 AM

DateTimeprivate: System::Void button1_Click(System::Object^ sender,


{


textBox1->Text= Day >ToString();

}

10/6/2010 12:00:00 AM



{


textBox1->Text= Day->ToLocalTime().ToString();

}

10/6/2010 3:00:00 AM

int window= 10;int freq= 60 * 60 * 2; // 2 hours;

DateTime d1= DateTime.Now;

DateTime d2= d1->AddSeconds(2 * window);DateTime d3= d1->AddSeconds(-2 * window);DateTime d4= d1->AddSeconds(window / 2);DateTime d5= d1->AddSeconds(-window / 2);

DateTime d6= (d1.AddHours(2))->AddSeconds(2 * window);DateTime d7= (d1.AddHours(2))->AddSeconds(-2 * window);DateTime d8= (d1.AddHours(2))->AddSeconds(window / 2);DateTime d9= (d1.AddHours(2))->AddSeconds(-window / 2);

Console.WriteLine("d1 ({0}) ~= d1 ({1}): {2}“, d1, d1, RoughlyEquals(d1, d1, window, freq));Console.WriteLine("d1 ({0}) ~= d2 ({1}): {2}", d1, d2, RoughlyEquals(d1, d2, window, freq));Console.WriteLine("d1 ({0}) ~= d3 ({1}): {2}", d1, d3, RoughlyEquals(d1, d3, window, freq));Console.WriteLine("d1 ({0}) ~= d4 ({1}): {2}", d1, d4, RoughlyEquals(d1, d4, window, freq));Console.WriteLine("d1 ({0}) ~= d5 ({1}): {2}", d1, d5, RoughlyEquals(d1, d5, window, freq));

Console.WriteLine("d1 ({0}) ~= d6 ({1}): {2}", d1, d6, RoughlyEquals(d1, d6, window, freq));Console.WriteLine("d1 ({0}) ~= d7 ({1}): {2}", d1, d7, RoughlyEquals(d1, d7, window, freq));Console.WriteLine("d1 ({0}) ~= d8 ({1}): {2}", d1, d8, RoughlyEquals(d1, d8, window, freq));Console.WriteLine("d1 ({0}) ~= d9 ({1}): {2}", d1, d9, RoughlyEquals(d1, d9, window, freq));

DateTime

Properties

Properties

• A compromise between a function and a variable! • See, the following, how awesome!

private:

int MyInt;

public:

// property block

property int intProperty

{

int get()

{

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}

Properties

The property keyword introduces the declaration of a property and can appear in a class, interface, or value type. A property can have a getter function (read only), a setter function (write only), or both (read-write).

public:

int MyInt;

// property block


{

int get()

{

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}

Properties

• So, how to use it? Like the following …property int intProperty

{

int get()

{

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}



{

textBox1->Text= intProperty.ToString();

}

Properties

Properties

• So, how to use it? Like the following …property int intProperty

{

int get()

{

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}



{

intProperty= 5;


}

Properties

Properties

int MyInt;

// property block


{

int get()

{

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}



{

intProperty= 5;


intProperty= 14;

textBox1->Text += " " + intProperty.ToString();

}

Properties

Propertiesint MyInt;

// property block


{

int get()

{

MessageBox::Show("You are lucky to know the property

before others:P:D");

return MyInt;

}

void set(int value)

{

MyInt= value;

}

}

#pragma endregion



{

intProperty= 5;


}

Properties

Propertiesint MyInt;

// property block


{

int get()

{

return MyInt;

MessageBox::Show("You are lucky to know the property

before others:P:D");

}

void set(int value)

{

MyInt= value;

}

}

#pragma endregion



{

intProperty= 5;


}

Note where it is!

Properties

No message box

string\int Conversion


• NewLine:– Environment::NewLine;

• Converting from string to int:– Int32::Parse(textBox1->Text);

– Int32::TryParse(textBox1->Text);


• Converting from int to string:– Exp #1:

• int x;• textBox1->Text= x.ToString();

– Exp #2:• int x̂; • textBox1->Text= x->ToString();

– Exp #3:• int x̂;• String ^S= x->ToString();

string\int Conversionprivate: System::Void button1_Click_1(System::Object^ sender,


{

int i= 3;

i= int::Parse(textBox1->Text);

}

What happens if we have “435345” in textBox1?

What happens if we have “wewe” in textBox1?

What happens if we have “213s” in textBox1?

What happens if we have “” in textBox1?

private: System::Void button1_Click_1(System::Object^ sender,


{

int i= 3;

i= int::TryParse(textBox1->Text, i ;

}

What happens if we have “435345” in textBox1?

What happens if we have “wewe” in textBox1?

What happens if we have “213s” in textBox1?

What happens if we have “” in textBox1?


Files! The Concept

Working with Files

• using!

using namespace System::IO;

void FileManipulate::PrintTextFile (){

String ^FilePath = "D:\\HashFile.Txt" ;

FileStream ^MyFile = gcnew FileStream(FilePath, FileMode::Open);

StreamReader ^SR = gcnew StreamReader(MyFile);String ^str="" ;

// Extracting words while(SR->Peek() > -1){

str = SR->ReadLine();MyForm->textBox1->Text += str + Environment::NewLine ;

}

MyFile->Close();}


void FileManipulate::PrintTextFile (){

String ^FilePath = "D:\\HashFile.Txt" ;

FileStream ^MyFile = gcnew FileStream ;

StreamReader ^SR = gcnew StreamReader(MyFile);String ^str="" ;

// Extracting words while(SR->Peek() > -1){

str = SR->ReadLine();MyForm->textBox1->Text += str + Environment::NewLine ;

}

MyFile->Close();}

Compiler errorFileStream ^MyFile = gcnew FileStream(FilePath, FileMode::Open);


Working with Filesprivate: System::Void Form1_Load(System::Object^ sender,


{

SaveFileDialog ^Dialog = gcnew SaveFileDialog();

FileStream ^MyFC ;

String ^FilePath = "" ;

if (Dialog->ShowDialog() ==

System::Windows::Forms::DialogResult::OK)

{

FilePath = Dialog->FileName ;

}

Working with FilesMyFC = File::Create(FilePath) ;

MyFC->Close();

MyFC = File::Open(FilePath ,FileMode::Append );

StreamWriter ^SW = gcnew StreamWriter(MyFC);

SW->WriteLine("I AM ZGTR");

SW->WriteLine("I AM ALWAYS ZGTR");

SW->Close();

MyFC->Close();

MyFC = File::Open(FilePath ,FileMode::Open );

StreamReader ^SR = gcnew StreamReader(MyFC);

String ^str="" ;

// Extracting words

while(SR->Peek() > -1)

{

str = SR->ReadLine();

this->textBox1->Text += str + Environment::NewLine ;

}

MyFC->Close();

}

Working with FilesMyFC = File::Create(FilePath) ;

MyFC->Close();

MyFC = File::Open(FilePath ,FileMode::Append );

StreamWriter ^SW = gcnew StreamWriter(MyFC);

while (textBox1->Text!= “000”)

{ SW-> WriteLine(textBox2->Text) ;}

SW->Close();

MyFC->Close();

MyFC = File::Open(FilePath ,FileMode::Open );

StreamReader ^SR = gcnew StreamReader(MyFC);

String ^str="" ;

// Extracting words

while(SR->Peek() > -1)

{

str = SR->ReadLine();

this->textBox1->Text += str + Environment::NewLine ;

}

MyFC->Close();

}

Working with Files

Working with FilesLive test

Use the console to track\debug values!Do not use messagebox for tracking!

Change between Console and Windows Form• In the project properties for all configurations (Project |

Properties, choose Configuration 'All Configurations', locate Config Properties -> Linker -> System), change the SubSystemfrom Console to Windows.

Change between Console and Windows Form

Project output type example

• Let’s have the following design


• And the following code-behind


• After setting the project output to “console”, Run


• Now, press the button multiple times and there you go!

Creating You Own Windows Forms Control (C++)

http://msdn.microsoft.com/en-us/library/vstudio/ms235628(v=vs.100).aspx

http://msdn.microsoft.com/en-us/library/vstudio/ms235628(v=vs.100).aspx

Peak on Exception Handlingtry, catch, throw and finally

private: System::Void panel1_MouseClick(System::Object^ sender,

System::Windows::Forms::MouseEventArgs^ e)

{

try

{

if (textBox1->text == “Hi”)

{

MessageBox::Show(“It’s time for Exceptions! ");

}

}

catch (System::FormatException ^e)

{

MessageBox::Show("You Should Enter a String in textBox first ");

}

}

Peak on Exception Handling

• Test it live!

Mohammad Shakermohammadshakergtr.wordpress.com

C++.NET Windows Forms Course@ZGTRShaker

C++.NET Windows Forms Course

Strings

Welcome!

Strings in Action

Strings in Action-> and ::

Strings in Action

• Let’s have the following form …

Strings in Action

• What happens?



{

int i = 3;

i++;

String ^Str = textBox1->Text;

String ^TempStr =String::Format("{0}{1}{2}" , Str , "What?" ,

i.ToString());

textBox2->Text += TempStr;

}

Strings in Action

Strings in Action

private: System::Void button1_Click(System::Object^

sender, System::EventArgs^ e)

{

int i = 3;

i++;


String ^TempStr = String::Format("{0}{1} Go! {2}" , Str ,

" What? " , i.ToString());


}

Strings in Action

Strings in Action

• Is it okay?

private: System::Void button1_Click(System::Object^


{

int i = 3;

i++;


String ^TempStr = String::Format("{0}{1} Go! {2}" , Str ,

" What? " , i);


}

Strings in Action

String Operations by Category

Strings in Action

• Comparing Strings (int):– Compare :

• returns an integer that indicates the relationship of one string to a second string in the sort order.

http://msdn.microsoft.com/en-us/library/system.string.compare.aspx

Strings in Action

Value Condition

Less than zero strA is less than strB.

Zero strA equals strB.

Greater than zero strA is greater than strB.

Strings in Actionprivate: System::Void button1_Click(System::Object^


{

String ^str1 = "I Wanna go!";

String ^str2 = "I decided not to go!";

int i = String::Compare(str1,str2);

textBox1->Text = i.ToString();

}

Strings in Action

• Testing Strings for Equality (bool):– You call the Equals method to determine whether two strings are

equal.

http://msdn.microsoft.com/en-us/library/system.string.equals.aspx

Strings in Action



{


String ^str2 = "I decided not to go!";

bool b= String::Equals(str1,str2);

textBox1->Text = b.ToString();

}

Strings in Action



{



bool b = String::Equals(str1,str2);


}

true

Strings in Action



{


String ^str2 = "I Wanna go! ";

bool b = String::Equals(str1,str2);


}

false

Strings in Action

• Finding Characters in a String :– The String class includes two kinds of search methods:

• Methods that return a “ bool” value to indicate whether a particular substring is present in a string instance. These include the Contains, EndsWith, and StartsWith methods.

• Methods that indicate the starting position of a substring in a string instance “int”. These include the IndexOf,IndexOfAny, LastIndexOf, and LastIndexOfAny methods.

http://msdn.microsoft.com/en-us/library/dy85x1sa.aspx

http://msdn.microsoft.com/en-us/library/system.string.endswith.aspx

http://msdn.microsoft.com/en-us/library/system.string.startswith.aspx

http://msdn.microsoft.com/en-us/library/system.string.indexof.aspx

http://msdn.microsoft.com/en-us/library/system.string.indexofany.aspx

http://msdn.microsoft.com/en-us/library/system.string.lastindexof.aspx

http://msdn.microsoft.com/en-us/library/system.string.lastindexofany.aspx

Strings in Action

• String::Contains Method (bool)– Returns a value indicating whether the specified String object occurs

within this string.

http://msdn.microsoft.com/en-us/library/system.string.aspx

Strings in Action

{String^ s1 = "The brown fox jumps over the lazy dog";String^ s2 = "fox";bool b;b = s1->Contains( s2 );Console::WriteLine( "Is the string, s2, in the string, s1?: {0}", b );

}

Is string , s2, in string, s1? True

Strings in Action

• String::IndexOf Method (int)– Reports the index of the first occurrence of one or more characters,

or the first occurrence of a string, within this string.

– This member is overloaded. For complete information about this member, including syntax, usage, and examples, click a name in the overload list.

Name Description

IndexOf(Char) Reports the index of the first occurrence of the specified Unicode character in this string.

IndexOf(String) Reports the index of the first occurrence of the specified string in this instance.

IndexOf(Char, Int32) Reports the index of the first occurrence of the specified Unicode character in this string. The search starts at a specified character position.

IndexOf(String, Int32) Reports the index of the first occurrence of the specified string in this instance. The search starts at a specified character position.

IndexOf(String, StringComparison)

Reports the index of the first occurrence of the specified string in the current Stringobject. A parameter specifies the type of search to use for the specified string.

IndexOf(Char, Int32, Int32)

Reports the index of the first occurrence of the specified character in this instance. The search starts at a specified character position and examines a specified number of character positions.

IndexOf(String, Int32, Int32)

Reports the index of the first occurrence of the specified string in this instance. The search starts at a specified character position and examines a specified number of character positions.

IndexOf(String, Int32, StringComparison)

Reports the index of the first occurrence of the specified string in the current Stringobject. Parameters specify the starting search position in the current string and the type of search to use for the specified string.

IndexOf(String, Int32, Int32, StringComparison)

Reports the index of the first occurrence of the specified string in the current Stringobject. Parameters specify the starting search position in the current string, the number of characters in the current string to search, and the type of search to use for the specified string.

int main(array<System::String ^> ^args)

{

Console::WriteLine(L"Hello World");

// Create a Unicode String with 5 Greek Alpha characters

String^ szGreekAlpha = gcnew String( L'\x0319',5 );

// Create a Unicode String with a Greek Omega character

wchar_t charArray5[3] = {L'\x03A9',L'\x03A9',L'\x03A9'};

String^ szGreekOmega = gcnew String( charArray5,2,1 );

String^ szGreekLetters = String::Concat( szGreekOmega, szGreekAlpha, szGreekOmega-

>Clone() );

// Examine the result

Console::WriteLine( szGreekLetters );

// The first index of Alpha

int ialpha = szGreekLetters->IndexOf( L'\x0319' );

// The last index of Omega

int iomega = szGreekLetters->LastIndexOf( L'\x03A9' );

Console::WriteLine( String::Concat( "The Greek letter Alpha first appears at

index ", Convert::ToString( ialpha ) ) );

Console::WriteLine( String::Concat( " and Omega last appears at index ",

Convert::ToString( iomega ), " in this String." ) );

return 0;

}

Strings in Action

Hello World

Ω?????Ω

The Greek letter Alpha first appears at index 1

and Omega last appears at index 6 in this String.

Press any key to continue . . .

Strings in Action–Trim() method

• String::Trim Method– Removes all leading and trailing white-space characters from the

current String object.


int main(){

String^ animal1 = "fox";String^ animal2 = "dog";String^ strTarget = String::Format( "The {0} jumped over the {1}.", animal1, animal2 );

Console::WriteLine( "The original string is:{0}{1}{0}", Environment::NewLine, strTarget );

Console::Write( "Enter an adjective (or group of adjectives) to describe the {0}: ==> ", animal1 );

String^ adj1 = Console::ReadLine();

Console::Write( "Enter an adjective (or group of adjectives) to describe the {0}: ==> ", animal2 );

String^ adj2 = Console::ReadLine();adj1 = String::Concat( adj1->Trim(), " " );adj2 = String::Concat( adj2->Trim(), " " );strTarget = strTarget->Insert( strTarget->IndexOf( animal1 ), adj1 );strTarget = strTarget->Insert( strTarget->IndexOf( animal2 ), adj2 );

Console::WriteLine( " {0}The final string is: {0} {1}", Environment::NewLine, strTarget );}

Strings in Action

The original string is:The fox jumped over the dog.

Enter an adjective (or group of adjectives) to describe the fox: ==> bold

Enter an adjective (or group of adjectives) to describe the dog: ==> lazy

The final string is:The bold fox jumped over the lazy dog.

Strings in Actionprivate: System::Void button1_Click(System::Object^ sender,


{


String ^str2 = "I DeciDEd not to go!";

str2 = str2->ToLower();

textBox1->Text = str2;

}



{


String ^str2 = "I decided not to go! ";

str2 = (str2->ToLower())->Trim() ;

textBox1->Text = str2+str1;

}



{


String ^str2 = “ I DeCided not to go! ";

str2 = (str2->ToLower())->Trim() ;

textBox1->Text = str2;

}

Strings in Action

• String::Copy Method (String to String)– Creates a new instance of String with the same value as a specified String.

// Sample for String::Copy()using namespace System;int main(){

String^ str1 = "abc";String^ str2 = "xyz";Console::WriteLine( "1) str1 = '{0}'", str1 );Console::WriteLine( "2) str2 = '{0}'", str2 );Console::WriteLine( "Copy..." );str2 = String::Copy( str1 );Console::WriteLine( "3) str1 = '{0}'", str1 );Console::WriteLine( "4) str2 = '{0}'", str2 );

}

1) str1 = 'abc'2) str2 = 'xyz'Copy...3) str1 = 'abc'4) str2 = 'abc'



Strings in Action

• String::CopyTo Method (String)– Copies a specified number of characters from a specified position in

this instance to a specified position in an array of Unicode characters.

Strings in Action

• Parameters– sourceIndexType: System::Int32

The index of the first character in this instance to copy.

– destinationType: array<System::Char>An array of Unicode characters to which characters in this instance are copied.

– destinationIndexType: System::Int32The index in destination at which the copy operation begins.

– countType: System::Int32The number of characters in this instance to copy to destination.

using namespace System;int main(){

// Embed an array of characters in a stringString^ strSource = "changed";array <Char> ^destination = {'T','h','e',' ','i','n','i','t','i','a','l','

','a','r','r','a','y'};

// Print the char arrayConsole::WriteLine( destination );

// Embed the source string in the destination stringstrSource->CopyTo( 0, destination, 4, strSource->Length );

// Print the resulting arrayConsole::WriteLine( destination );strSource = "A different string";

// Embed only a section of the source string in the destinationstrSource->CopyTo( 2, destination, 3, 9 );

// Print the resulting arrayConsole::WriteLine( destination );

}

Strings in Action

The initial array

The changed array

Thedifferentarray

Press any key to continue . . .

Strings in Action

• String::Replace Method (String , String)– Returns a new string in which all occurrences of a specified string in

the current instance are replaced with another specified string.

Strings in Action

using namespace System;int main(){

String^ errString = "This docment uses 3 other docments to docment the docmentation";

Console::WriteLine( "The original string is:\n'{0}'\n", errString );

// Correct the spelling of S"document".String^ correctString = errString->Replace( "docment", "document" );Console::WriteLine( "After correcting the string, the result is:\n'{0}'",

correctString );}

This code example produces the following output:The original string is:'This docment uses 3 other docments to docment the docmentation'

After correcting the string, the result is:'This document uses 3 other documents to document the documentation'

SubString()

SubString()private: System::Void button1_Click(System::Object^ sender,


{



String ^TempStr = "";

TempStr = str2->Substring(3);

textBox1->Text = TempStr;

}

SubString()private: System::Void button1_Click(System::Object^ sender,


{



String ^TempStr = "";

TempStr = str2->Substring(3,3);

textBox1->Text = TempStr;

}

That’s it for today!

C++ Windows Forms L06 - Utlitity and Strings

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Transcript of C++ Windows Forms L06 - Utlitity and Strings