Display colors in StringGrid (via event OnDrawCell)

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void __fastcall TForm1::Button1Click(TObject *Sender)

{ int m, n, i, j;

int gridSize;

RichEdit1->Clear();

PageControl1->ActivePage = TabSheet1;

m = Edit1->Text.ToInt();

n = Edit2->Text.ToInt();

gridSize = Edit3->Text.ToInt();

StringGrid1->RowCount = m;

StringGrid1->ColCount = n;

StringGrid1->FixedCols= 2; // # of Column headers

StringGrid1->FixedRows= 2; // # of Row headers

StringGrid1->GridLineWidth = 1; StringGrid1->DefaultDrawing = false;

for (i=0; i<m; i++) StringGrid1->ColWidths[i] = gridSize;

for (i=0; i<n; i++) StringGrid1->RowHeights[i] = gridSize;

for (i=0; i<m; i++)

{ for (j=0; j<n; j++)

{ StringGrid1->Cells[j][i] = rand() % 3;

RichEdit1->Lines->Add("Cell["+IntToStr(i)+", "+IntToStr(j)+"] = "+StringGrid1->Cells[j][i]);

if (CheckBox1->Checked)

{ Sleep(TrackBar1->Position);

StringGrid1->Refresh();

}

}

}

Button3->Enabled = true;

}

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void __fastcall TForm1::StringGrid1DrawCell(TObject *Sender, int ACol, int ARow, TRect &Rect, TGridDrawState State)

{ String text = StringGrid1->Cells[ACol][ARow];

if (text == "0") StringGrid1->Canvas->Brush->Color = TColor RGB(250, 245, 135);

else if (text == "1") StringGrid1->Canvas->Brush->Color = TColor (RGB(176, 36, 132));

else if (text == "2") StringGrid1->Canvas->Brush->Color = TColor (RGB(180, 180, 80));

else StringGrid1->Canvas->Brush->Color = TColor RGB(50, 50, 50);

StringGrid1->Canvas->FillRect(Rect);

// StringGrid1->Canvas->TextRect(Rect, Rect.Left+6, Rect.Top+8, text);

}

Change colors of cells in StringGrid one by one to achieve animations (DoubleBuffered, Refresh)

void __fastcall TForm1::Button3Click(TObject *Sender)

{ int m, n, i, j, k;

PageControl1->ActivePage = TabSheet1;

m = Edit1->Text.ToInt();

n = Edit2->Text.ToInt();

if (CheckBox2) DoubleBuffered = true;

else DoubleBuffered = false;

// 畫面重新繪製時，會出現閃爍的狀況；在Panel或Form上設置DoubleBuffered的屬性為true即可

//Form1->DoubleBuffered = true;

for (i=0; i<m; i++)

{ for (j=0; j<n; j++)

{ Sleep(TrackBar1->Position);

k = StringGrid1->Cells[j][i].ToInt();

StringGrid1->Cells[j][i] = 3;

StringGrid1->Refresh();

StringGrid1->Cells[j][i] = k;

}

}

}

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More colors/refreshes in StringGrid

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void __fastcall TForm1::Button2Click(TObject *Sender)

{ int m, n, i, j;

RichEdit1->Clear();

PageControl1->ActivePage = TabSheet3;

m = Edit1->Text.ToInt();

n = Edit2->Text.ToInt();

StringGrid2->RowCount = m;

StringGrid2->ColCount = n;

StringGrid2->FixedCols= 0; // # of Column headers

StringGrid2->FixedRows= 0; // # of Row headers

StringGrid2->GridLineWidth = 1; StringGrid2->DefaultDrawing = false;

for (i=0; i<m; i++) StringGrid2->ColWidths[i] = 24;

for (i=0; i<n; i++) StringGrid2->RowHeights[i] = 24;

StringGrid2->Refresh();

if (CheckBox1->Checked)

{ for (i=0; i<m; i++)

{ for (j=0; j<n; j++)

{ Sleep(TrackBar1->Position);

StringGrid2->Refresh();

}

}

}

}

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void __fastcall TForm1::StringGrid2DrawCell(TObject *Sender, int ACol, int ARow, TRect &Rect, TGridDrawState State)

{ int rr = rand()%256, rg = rand()%256, rb = rand()%256;

RichEdit1->Lines->Add("(r, g, b) = ("+IntToStr(rr)+","+IntToStr(rg)+","+IntToStr(rb)+")");

// StringGrid2->Canvas->Brush->Color = static_cast <TColor>(RGB(rr, rg, rb));

StringGrid2->Canvas->Brush->Color = TColor (RGB(rr, rg, rb));

StringGrid2->Canvas->FillRect(Rect);

}

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