Month
Month
3rd Tuesday of the month. 7:30PM - C/C++ Group, SPRS
Welcome to the C++ Users Group. This group is a "Special Interest Group" of the ACGNJ devoted to discussing programming languages in general and C, C++, and C++ for Windows programming in particular. Each month a small but hopefully useful program (complete with source code) is presented for discussion.
Object of the Disk Free Space Program: To present a small utility which draws a Pie Chart showing the free space on the main hard drive, usually "C:". It demonstrates a new system of graphic programming objects introduced by Microsoft called "GDIPLUS", or "GDI+".At the meeting on Tuesday night we will be discussing the utility and the source code.
SAMPLE CODE
===========
void CPie1Dlg::DrawResults(HDC hdc)
{
RECT rr;
GetClientRect(&rr);
Graphics graphics(hdc);
// Create a SolidBrush object.
SolidBrush blackBrush(Color(255, 0, 0, 0));
SolidBrush greyBrush(Color(255, 224, 224, 224));
SolidBrush usedBrush(Color(255, 0, 0, 0));
if (fPercentUsed >= 95.)
usedBrush.SetColor(Color(255, 255, 0, 0)); // red
else if (fPercentUsed >= 75.)
usedBrush.SetColor(Color(255, 255, 192, 0)); // yellow
else
usedBrush.SetColor(Color(255, 0, 255, 0)); // green
// Create a Pen object.
Pen blackPen(Color(255, 0, 0, 0), 3);
blackPen.SetDashStyle(DashStyleDot); // Make it dotted instead of solid.
// Define the pie.
Rect ellipseRect(0, 0, rr.right, rr.bottom);
ellipseRect.Inflate(-3,-3);
REAL startAngle = 0.0f;
REAL sweepAngle = 3.6f * (100.0f - fPercentUsed);
// Draw the pie.
graphics.FillPie(&greyBrush, ellipseRect, startAngle, sweepAngle);
graphics.FillPie(&usedBrush, ellipseRect, sweepAngle, 360 - sweepAngle);
graphics.DrawPie(&blackPen, ellipseRect, startAngle, sweepAngle);
graphics.DrawPie(&blackPen, ellipseRect, sweepAngle, 360 - sweepAngle);
// Create a string.
char text[256];
sprintf(text, "FREE\n%.1f%%\n%s\n%ld MB",
100.0-fPercentUsed, sTargetDrive.GetBuffer(100), ulFreeMegs);
WCHAR freetext[256]; // convert string to wide-characters
ZeroMemory(freetext, sizeof(freetext));
mbstowcs(freetext, text, strlen(text));
// Initialize arguments and then draw string inside box.
REAL x, y, width, height;
x = (float) (3*rr.right)/4;
y = (float) rr.bottom/2;
width = (float) (rr.right - x);
height = (float)(rr.bottom - y);
RectF layoutRect(x, y, width, height); // rectangle defines boundary of string.
Font myFont(L"Arial", 16, FontStyleBold); // define font.
StringFormat format;
format.SetAlignment(StringAlignmentNear); // align it near the x,y origin.
// Draw string.
graphics.DrawString(freetext, -1, &myFont, layoutRect, &format, &blackBrush);
}