C # GDI + draw a line chart (for the first version)

/// <Summary>
/// Create a line chart
/// </Summary>
/// <Param name = "X"> center x value </param>
/// <Param name = "Y"> center point y value </param>
/// <Param name = "xylength"> X, Y axis length </param>
/// <Param name = "xstring"> X axis description </param>
/// <Param name = "ystring"> Y axis description </param>
/// <Param name = "xinfo"> X Data </param>
/// <Param name = "yinfo"> Y data </param>
/// <Param name = "maxpoint"> obtain the maximum Y axis data from the database </param>

Public bitmap createline (float X, float y, float xylength, string xstring, string ystring, string [] xinfo, float [] yinfo, float maxpoint)
{
Bitmap bitmap = new Bitmap (this. Width, this. Height); // defines the canvas
Graphics G = graphics. fromimage (Bitmap );
G. Clear (color. White );

Pointf P = new pointf (x, y); // center point
Pointf [] xpt = new pointf [3] {New pointf (P. X + xylength + 15, p. y), new pointf (P. X + xylength, P. y-8), new pointf (P. X + xylength, P. Y + 8)}; // X axis triangle
Pointf [] Ypt = new pointf [3] {New pointf (P. x, p. y-xylength-15), new pointf (P. x-8, p. y-xylength), new pointf (P. X + 8, p. y-xylength)}; // y-axis triangle

// X
G. drawline (pens. Black, p. x, P. Y, p. x + xylength, P. y );
G. drawpolygon (pens. Black, xpt );
G. fillpolygon (brushes. Black, xpt );
G. drawstring (xstring, new font ("", 12), new solidbrush (color. Red), p. x + xylength + 10, p. Y + 10 );

// Y
G. drawline (pens. Black, p. x, P. Y-xylength, p. x, P. y );
G. drawpolygon (pens. Black, Ypt );
G. fillpolygon (brushes. Black, Ypt );
G. drawstring (ystring, new font ("", 12), new solidbrush (color. Red), p. x-40, p. Y-xylength-30 );
// Pixel
Int point = (INT) (p. Y/xinfo. Length );

Int ypoint = 0;
If (maxpoint. tostring (). substring (0, 1) = "1 ")
{
Ypoint = 10;
}
Else
{
Int sale = convert. toint32 (maxpoint );
Int length = sale. tostring (). length;
String max = maxpoint. tostring (). substring (0, 1 );
String cz = "1 ";
For (int A = 1; A <length; A ++)
{
CZ + = "0 ";
Max + = "0 ";
}
Maxpoint = convert. tosingle (CZ) + convert. tosingle (max );
Ypoint = (INT) (maxpoint/convert. tosingle (CZ ));

}

// Draw the y Scale
For (INT Kd = 1; KD <= ypoint; KD ++)
{
Float kdy = P. Y-(360/maxpoint) * (maxpoint/ypoint * kD );
G. drawstring (convert. tostring (maxpoint/ypoint * kD), new font ("", 10), brushes. Black, p. x-40, kdy-5 );
G. drawline (pens. Black, p. x-5, kdy, p. x, kdy );
}

For (INT I = 0; I <xinfo. length; I ++)
{

// Draw the X axis Project
G. drawstring (xinfo [I], new font ("", 10), brushes. black, new pointf (P. X + I * point-5, p. Y + 5 ));

G. drawellipse (pens. Black, p. x + I * point-1.5f, P. Y-360/maxpoint * yinfo [I], 3, 3 );
G. fillellipse (New solidbrush (color. Black), p. x + I * point-1.5f, P. Y-360/maxpoint * yinfo [I], 3, 3 );

// Draw a value
G. drawstring (yinfo [I]. tostring (), new font ("", 10), brushes. black, P. X + I * point, P. y-360/maxpoint * yinfo [I]);
// Draw line
If (I + 1 <xinfo. length)
G. drawline (pens. red, P. X + I * point, P. y-360/maxpoint * yinfo [I], p. X + (I + 1) * point, P. y-360/maxpoint * yinfo [I + 1]);
}
Return bitmap;
}

 

// Call in the form

Dataset DS = dbuitily. executequerysql ("select * From t_users"); // X-axis data source
String [] users = new string [Ds. Tables [0]. Rows. Count];
Float [] sales = new float [Ds. Tables [0]. Rows. Count];
For (INT I = 0; I <Ds. Tables [0]. Rows. Count; I ++)
{
Users [I] = Ds. Tables [0]. Rows [I] [0]. tostring ();
Sales [I] = convert. tosingle (dbuitily. executescalarsql ("select sum (salemoney) from t_sales where userid = '" + users [I] + "'"); // ordinate the data source
}
Float maxvalue = convert. tosingle (dbuitily. executescalarsql ("select sum (salemoney) from t_sales group by userid order by sum (salemoney) DESC "));

Picchart. Image = createline (300,450,400, "employee ID", "sales price (RMB)", users, sales, maxvalue );

Slice: