ASP. NET line chart-(3) Specific Drawing

1. Create a bitmap and use graphics to draw and annotate text. The specific code is as follows:

Bitmap image = new Bitmap (width, height );
Graphics graphics = graphics. fromimage (image );
Try
{
Graphics. Clear (color. White );
Font font = new font ("Arial", 9, fontstyle. Regular); // font used for the coordinate scale
Font font1 = new font ("", 15, fontstyle. Regular); // font used for the image title
Font font2 = new font ("", 10, fontstyle. Regular); // font used to annotate Information
Lineargradientbrush brush = new lineargradientbrush (New rectangle (0, 0, image. width, image. height), color. gray, color. gray, 1.2f, true); // draw the lineargradientbrush of the gridline.
Lineargradientbrush brush2 = new lineargradientbrush (New rectangle (0, 0, image. width, image. height), color. red, color. red, 1.2f, true); // lineargradientbrush for commenting Information
Lineargradientbrush brush3 = new lineargradientbrush (New rectangle (0, 0, image. width, image. height), color. green, color. green, 1.2f, true); // lineargradientbrush for commenting Information
Lineargradientbrush brush4 = new lineargradientbrush (New rectangle (0, 0, image. width, image. height), color. brown, color. brown, 1.2f, true); // lineargradientbrush for commenting Information

Graphics. fillrectangle (brushes. White, 0, 0, width, height );
Brush brush1 = new solidbrush (color. Black );
If (manqpfl. length> 0 & manqpfl1.length> 0 & manqpfl2.length> 0)
{
Graphics. drawstring ("from" + minyear. tostring () + "year" + minmonth. tostring () + "month to" + maxyear. tostring () + "year" + maxmonth. tostring () + "full month line chart", font1, brush1, new pointf (width/2-200, 30); // mark the image title
Graphics. drawstring ("business insurance is a red line", font2, brush2, new pointf (width/2 + 200,500); // annotation information
Graphics. drawstring ("", font2, brush3, new pointf (width/2 + 200,530); // annotation information
Graphics. drawstring ("car insurance is brown line", font2, brush4, new pointf (width/2 + 200,560); // annotation information
}
// Draw the border line of the image
Graphics. drawrectangle (new pen (color. Black), 0, 0, image. Width-1, image. Height-1 );

// Draw the Y axis
Int x = 60;
Pen mypen1 = new pen (color. Black, 2 );
Graphics. drawline (mypen1, X, 120, X, 458 );
// Draw the grid vertical line
Pen mypen = new pen (brush, 1 );
For (INT I = 0; I <totalmonths; I ++)
{
Graphics. drawline (mypen, X, 120, X, 458 );
X = x + 60; // each 60 pixels on the Y axis is a unit scale.
}
// Draw a grid line
Int y= 158;
For (INT I = 0; I <5; I ++)
{
Graphics. drawline (mypen, 60, Y, width-15, y );
Y = Y + 60; // every 60 pixels on the X axis is a unit scale.
}
// Draw the X axis
Graphics. drawline (mypen1, 60, Y, width-15, y );

// Mark the x-axis text
X = 35;
For (INT I = 0; I <totalmonths; I ++)
{
String month = Ds. tables [0]. rows [I] ["YY"]. tostring () + ". "+ Ds. tables [0]. rows [I] ["mm"]. tostring ();
Graphics. drawstring (month. tostring (), Font, brushes. Red, X, 460); // you can specify the text content and output position.
X = x + 60; // every 60 pixels on the X axis is a unit scale.
}
// Y-axis text
String [] M = {"90", "80", "70", "60", "50", "40 "};
Y = 150;
For (INT I = 0; I <6; I ++)
{
Graphics. drawstring (M [I]. tostring (), Font, brushes. Red, 25, Y); // you can specify the text content and output position.
Y = Y + 60; // every 60 pixels on the Y axis is a unit scale.
}

Int [] Count = new int [totalmonths];
Int [] count1 = new int [totalmonths];
Int [] count2 = new int [totalmonths];
For (Int J = 0; j <totalmonths; j ++)
{
Count [J] = convert. toint32 (manqpfl [J] * 360/60); // calculates the relative displacement of the data point to the coordinate axis.
Count1 [J] = convert. toint32 (manqpfl1 [J] * 360/60 );
Count2 [J] = convert. toint32 (manqpfl2 [J] * 360/60 );
}

Point [] mypoint = caculatepoints (count, totalmonths); // obtain the absolute position of the data point on the screen.
Point [] mypoint1 = caculatepoints (count1, totalmonths );
Point [] mypoint2 = caculatepoints (count2, totalmonths );

Pen mypen2 = new pen (color. Red, 2); // The manqpfl line is red
Pen mypen3 = new pen (color. Green, 2); // The manqpfl1 line is green
Pen mypen4 = new pen (color. Brown, 2); // The manqpfl2 line is brown

Graphics. drawlines (mypen2, mypoint); // draw a manqpfl line
Graphics. drawlines (mypen3, mypoint1); // draw the manqpfl1 line
Graphics. drawlines (mypen4, mypoint2); // draw the manqpfl2 line

// Value of the labeled data point
For (INT I = 0; I <totalmonths; I ++)
{
Graphics. drawstring (manqpfl [I]. tostring (), Font, brushes. Blue, mypoint [I]. X-8, mypoint [I]. y );
Graphics. drawstring (manqpfl1 [I]. tostring (), Font, brushes. Blue, mypoint1 [I]. X-8, mypoint1 [I]. Y-15 );
Graphics. drawstring (manqpfl2 [I]. tostring (), Font, brushes. Blue, mypoint2 [I]. X-8, mypoint2 [I]. Y-15 );
}

// Outputs bitmap
System. Io. memorystream mstream = new system. Io. memorystream ();
Image. Save (mstream, system. Drawing. imaging. imageformat. GIF );
Response. clearcontent ();
Response. contenttype = "image/GIF ";
Response. binarywrite (mstream. toarray ());
// This. Mess. innerhtml = mstream. toarray (). tostring ();
}
Finally
{
Graphics. Dispose ();
Image. Dispose ();
}

 

// Calculate the coordinates of the midpoint of a line
Protected point [] caculatepoints (INT [] Count, int totalnumber)
{
Point [] mypoint = new point [totalnumber];
For (INT I = 0; I <totalnumber; I ++)
{
Mypoint [I]. x = 60 + I * 60; mypoint [I]. Y = 700-count [I];
}
Return mypoint;
}

 

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