12-mavzu: Visual C++ning grafik imkoniyatlari. Reja

Rasmlarni o‘zgartirish. Buning uchun fayllarni yuklash openFiledialog va fayllarni saqlash saveFiledialog komponentalaridan foydalanamiz. Buning uchun Brush – mo‘yqalamdan foydalanib, 1 ta komponenta, 3 ta button komponentasini oynaga qulay qilib joylashtiramiz. Button larning birinchisi, rasmni tahrirlashni tozalashni amalga oshiradi, ikkinchisi, tahrirlangan rasmni saqlash uchun, uchinchisi, rasmni tahrirlash uchun yuklashni amalga oshiradi. using namespace System::Drawing::Drawing2D; ni qo‘shishb qo‘yish kerak.

1. 
   qadam. Rasmlarni o‘zgartirish uchun ishlatiladigan o‘zgaruvchilarni eʻlon qilamiz.
   

private: Bitmap ^ bmp_for_draw;
private: Point start_point; private: bool Draw; public: Pen^ pen_for_draw;
private: String ^ full_name_of_image;

2. 
   qadam. Dastur oynasining Form1_Load hodisasiga dastlabki sozlamalarni
   

this->Text = "Rasmni tahrirlash"; button1->Text = "Tozalash"; button2->Text= "Rasmni saqlash"; button3->Text = "Rasmni yuklash";
pen_for_draw = gcnew Pen(Color::Black, 4);
pen_for_draw->StartCap = System::Drawing::Drawing2D::LineCap::Round; pen_for_draw->EndCap = System::Drawing::Drawing2D::LineCap::Round;
o‘rnatamiz.
Bunda komponentalarni sozlash va bir qalamni yaratib olish, uning StartCap, EndCap xususiyatlarini o‘rnatish amalga oshiriladi.

3. 
   qadam. Komponentdagi rasmni tozalash uchun button1_Click hodisaga algoritmni yozamiz.
   

Graphics^ grp = pictureBox1->CreateGraphics();
grp->Clear(SystemColors::Window);

4. 
   qadam. Sichqoncha komponentaning ustida kelganda chizishi uchun pictureBox1_MouseDown hodisasiga quyidagi algoritmni kiritamiz
   

if (e->Button == System::Windows::Forms::MouseButtons::Left){
Draw = true;
start_point = e->Location;
}

5. 
   qadam. Sichqoncha komponentaning ustida ketganda chizishni to‘xtatish uchun pictureBox1_MouseUp hodisasiga quyidagi algoritmni kiritamiz
   

if (e->Button == System::Windows::Forms::MouseButtons::Left){
Draw = false;
}

6. 
   qadam. Komponentaga kerakli rasmni yuklash uchun button3_Click hodisasiga quyidagi algoritmni yoziladi
   

OpenFileDialog ^ open_dialog = gcnew OpenFileDialog();
open_dialog->Filter = "Image Files(*.BMP;*.JPG;*.GIF;*.PNG)|*.BMP;*.JPG;*.GIF;*.PNG|All files (*.*)|*.*";
if (open_dialog->ShowDialog() == System::Windows::Forms::DialogResult::OK){ try{
full_name_of_image = open_dialog->FileName; bmp_for_draw = gcnew Bitmap(open_dialog->FileName);
//pictureBox1->Size = bmp_for_draw->Size;
pictureBox1->SizeMode = PictureBoxSizeMode::StretchImage; pictureBox1->Image = bmp_for_draw;
pictureBox1->Invalidate();
} catch(Exception^ e) {
System::Windows::Forms::DialogResult rezult = MessageBox::Show("Tanlangan faylni ochib bo'lmaydi "+ e->ToString(),"Diqqat", MessageBoxButtons::OK, MessageBoxIcon::Error);
}}
Bundagi asosi nuqson shundan iboratki, agar rasmning o‘lchamlari
komponentaning o‘lchamlari bilan bir xil bo‘lsa, yaxshi chizadi, bir xil bo‘lmasa, foydalanuvchi ekranining proporsiyasini olib chizadi.

7. 
   qadam. Komponentadagi rasmni saqlash uchun button2_Click hodisasiga quyidagi algoritmni yoziladi
   

if (pictureBox1->Image != nullptr){
String ^format = full_name_of_image->Substring(full_name_of_image->Length - 4, 4); SaveFileDialog ^savedialog = gcnew SaveFileDialog();
savedialog->Title = "Rasmni saqlash ..."; savedialog->OverwritePrompt = true; savedialog->CheckPathExists = true;
savedialog->Filter = "Image Files(*.BMP)|*.BMP|Image Files(*.JPG)|*.JPG|Image Files(*.GIF)|*.GIF|Image Files(*.PNG)|*.PNG|All files (*.*)|*.*";
savedialog->ShowHelp = true;
// If selected, save
if (savedialog->ShowDialog() == System::Windows::Forms::DialogResult::OK){ try{
bmp_for_draw->Save(savedialog->FileName, System::Drawing::Imaging::ImageFormat::Jpeg);
} catch(Exception ^ e) {
System::Windows::Forms::MessageBox::Show("Impossible to save image"+e->ToString(), "FATAL ERROR", MessageBoxButtons::OK, MessageBoxIcon::Error);
} } }

8. 
   qadam. Sichqoncha komponentaning ustida kelganda chizishi uchun
   

if (e->Button == System::Windows::Forms::MouseButtons::Left){ Graphics ^graf = Graphics::FromImage(pictureBox1->Image);
graf->DrawLine(pen_for_draw, start_point, e->Location); start_point = e->Location;
pictureBox1->Invalidate();
}
quyidagi algoritmni kiritamiz.
Dasturni ishlatganda quyidagi oyna chiqadi.

12.6-rasm. Rasmlarni tahrirlash.