/// <summary>
/// 获取系统dipi
/// </summary>
/// <returns></returns>
public static Dpi GetDPI()
{
using (ManagementClass mc = new ManagementClass("Win32_DesktopMonitor"))
{
Dpi ScreenDPI = new Dpi();
using (ManagementObjectCollection moc = mc.GetInstances())
{
int PixelsPerXLogicalInch = 0; // dpi for x
int PixelsPerYLogicalInch = 0; // dpi for y
foreach (ManagementObject each in moc)
{
PixelsPerXLogicalInch = int.Parse((each.Properties["PixelsPerXLogicalInch"].Value.ToString()));
PixelsPerYLogicalInch = int.Parse((each.Properties["PixelsPerYLogicalInch"].Value.ToString()));
ScreenDPI.DpiX = PixelsPerXLogicalInch;
ScreenDPI.DpiY = PixelsPerYLogicalInch;
}
}
return(ScreenDPI);
}
}
private static PrintDocument printDocument1 = new PrintDocument();//获取默认打印机
private void button1_Click(object sender, EventArgs e)
{
Dpi screenDpi = GetDPI();
Dpi gDpi = new Dpi((int)numDpiX.Value, (int)numDpiY.Value);
Pen penRed = new Pen(Color.Red, 1); //设置笔的粗细为,颜色为红色
Pen penGreen = new Pen(Color.Green, 1); //设置笔的粗细为,颜色为红色
Brush brushRed = new SolidBrush(Color.Black);
PointF p1_1 = new PointF();
PointF p1_2 = new PointF();
PointF p2_1 = new PointF();
PointF p2_2 = new PointF();
var xLen = CentimeterToPiToPixel(10, gDpi.DpiX);
var yLen = CentimeterToPiToPixel(10, gDpi.DpiY);
var mmxLen = CentimeterToPiToPixel(0.1f, gDpi.DpiX);
var mmyLen = CentimeterToPiToPixel(0.1f, gDpi.DpiY);
//设置一个30cm高15cm 的画布
Bitmap b1 = new Bitmap((int)CentimeterToPiToPixel(30, gDpi.DpiX), (int)CentimeterToPiToPixel(15, gDpi.DpiY));
b1.SetResolution(gDpi.DpiX, gDpi.DpiY);
Graphics g = Graphics.FromImage(b1);
p1_1 = new PointF(50, 40);
p1_2 = new PointF(p1_1.X + xLen, p1_1.Y);
p2_1 = new PointF(50, 40);
p2_2 = new PointF(p2_1.X, p2_1.Y + yLen);
//10cm 横线
g.DrawLine(penRed, p1_1, p1_2);
int m = 0, cm = 0;
//刻度
for (float i = 0, j = xLen; i <= j;)
{
if (m % 10 == 0 || i == j)
{
g.DrawLine(penRed, p1_1.X + i, p1_1.Y - 15, p1_1.X + i, p1_1.Y);
g.DrawString($"{cm}", new Font("宋体", 9f), brushRed, new PointF(p1_1.X + i - 2, p1_1.Y + 5f));
cm++;
}
if (m % 5 == 0 && m % 10 != 0)
{
g.DrawLine(penRed, p1_1.X + i, p1_1.Y - 10, p1_1.X + i, p1_1.Y);
}
else
{
g.DrawLine(penRed, p1_1.X + i, p1_1.Y - 5, p1_1.X + i, p1_1.Y);
}
i += mmxLen;
m++;
}
g.DrawLine(penRed, p1_2.X, p1_2.Y - 15, p1_2.X, p1_2.Y);
g.DrawString($"{cm}", new Font("宋体", 9f), brushRed, new PointF(p1_2.X - 2, p1_2.Y + 5f));
g.DrawLine(penRed, p2_1, p2_2);
//10cm竖线
m = 0;
cm = 0;
//刻度
for (float i = 0, j = yLen; i <= j;)
{
if (m % 10 == 0 || i == j)
{
g.DrawLine(penRed, p1_1.X - 15, p1_1.Y + i, p1_1.X, p1_1.Y + i);
g.DrawString($"{cm}", new Font("宋体", 9f), brushRed, new PointF(p1_1.X, p1_1.Y + i - 5f));
cm++;
}
if (m % 5 == 0 && m % 10 != 0)
{
g.DrawLine(penRed, p1_1.X - 10, p1_1.Y + i, p1_1.X, p1_1.Y + i);
}
else
{
g.DrawLine(penRed, p1_1.X - 5, p1_1.Y + i, p1_1.X, p1_1.Y + i);
}
i += mmyLen;
m++;
}
g.DrawLine(penRed, p2_2.X - 15, p2_2.Y, p2_2.X, p2_2.Y);
g.DrawString($"{cm}", new Font("宋体", 9f), brushRed, new PointF(p2_2.X, p2_2.Y - 5f));
g.DrawString($"画一根长度10cm的直线 屏幕DPI【{screenDpi.DpiX},{screenDpi.DpiY}】 画布DPI【{g.DpiX},{g.DpiY}】", new Font("宋体", 9f), brushRed, new PointF(p1_1.X + 20, p1_1.Y + 30f));
this.BackgroundImageLayout = ImageLayout.None;
this.BackgroundImage = b1;
//printDocument1 = new PrintDocument();
//printDocument1.PrintController = new StandardPrintController(); //不要打印进度框
//printDocument1.DefaultPageSettings.Landscape = false; //设置打印横向还是纵向
//printDocument1.PrintPage += new PrintPageEventHandler(MyPrintDoc1_PrintPage);
//try
//{
// printDocument1.Print();
// printDocument1.PrintPage -= new PrintPageEventHandler(MyPrintDoc1_PrintPage);
//}
//catch (Exception ex)
//{
// MessageBox.Show("请安装打印机", "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
//}
}
