Ios drawing, drawing coordinate system, drawing Coordinate System

Ios drawing, drawing coordinate system, drawing Coordinate System
Let's take a look at the effect:

 

Create a View class and add the Code directly:

 

// Only override drawRect: if you perform custom drawing. // An empty implementation adversely affects performance during animation. -(void) drawRect :( CGRect) rect {// obtain the current environment CGContextRef context = UIGraphicsGetCurrentContext (); // Save the current environment to restore CGContextSaveGState (context) in the future ); // organize the data for (int I = 0; I <self. dataArray. count; I ++) {NSString * x_data = self. dataArray [I] [@ xxx]; NSString * y_data = sel F. dataArray [I] [@ yyyy]; NSString * rate_data = self. dataArray [I] [@ rrr]; [x_array addObject: x_data]; [y_array addObject: y_data]; [rate_array addObject: rate_data];} // CGRect Rectangle = rect; // define a rectangular path UIBezierPath * path = [UIBezierPath bezierPathWithRect: Rectangle]; // draw a rectangular path [path stroke]; //////////////////////////////////////// /////////////// // public data float fdistance_left_fr Ame = 30.0; // The width of the border from the left X axis, used to draw the text float fdistance_bottom_frame = 15.0; // float fdistance_right_frame = 10.0 from the border on the left Y axis; // float fdraw_line_height = rect. size. height-fdistance_bottom_frame; // draw the height of the coordinate float fdraw_line_width = rect. size. width-fdistance_left_frame-fdistance_right_frame; // width of the drawn coordinate float f_x_axis_scale_number = 7.0; // float f_y_axis_scale_number = 7.0 on the X axis ;// Y axis scale float x_unit_distance_scale = 0.0; // offset of the X axis scale float y_unit_distance_scale = 0.0; // offset of the Y axis scale float x_unit_scale = 0.0; // span of the X axis Scale (one Proportional unit) float y_unit_scale = 0.0; // span of the Y axis Scale (one Proportional unit) // start to draw the X axis float left_bottom_x = rect. origin. x + fdistance_left_frame; float left_bottom_y = rect. origin. y + fdraw_line_height; CGPoint point_origin = CGPointMake (left_bottom_x, left_bottom_y); // coordinate axis origin // define a start Path UIBezierPath * x_startPath = [UIBezierPath bezierPath]; [x_startPath setLineWidth: 1.5]; [x_startPath moveToPoint: point_origin]; // set the starting point (coordinate origin) for (int x = 0; x <f_x_axis_scale_number; x ++) // draw a straight line {x_unit_scale = fdraw_line_height/f_x_axis_scale_number; // you can use the first-level equi-score to scale x_unit_distance_scale = x * x_unit_scale; // offset point relative to the origin [x_startPath addLineToPoint: CGPointMake (left_bottom_x, left_bottom_y-x_unit _ Distance_scale)]; // "|" float margin = left_bottom_y; float text_rect_top = middle-8-x_unit_distance_scale; float text_rect_bottom = Lower + 8-percent; // + 8-8, float text_rect_height = 16; CGRect margin = CGRectMake (2, text_rect_top, bottom, text_rect_height); CGContextSetLineWidth (context, 1.0 ); CG ContextSetRGBFillColor (context, 0.5, 0.5, 0.5, 0.5); UIFont * font = [UIFont boldSystemFontOfSize: 12.0]; // use NSString * x_strtext = [NSString stringWithFormat: @ % zi.00, x]; // draw the x axis scale value [x_strtext drawInRect: x_axis_rect withFont: font]; if (0 = x) {// when it is "0, no or the painting scale, draw the horizontal line "Y" axis float y_width = fdraw_line_width directly at the bottom; CGContextSetRGBStrokeColor (context, 0.5, 0.5, 0.5, 0.5); // The line color CGContextMoveToPoint (Context, left_bottom_x, left_bottom_y-rows); CGContextAddLineToPoint (context, left_bottom_x + y_width, left_bottom_y-rows); CGContextStrokePath (context ); // start to draw the Y axis UIBezierPath * y_startPath = [UIBezierPath bezierPath]; [y_startPath setLineWidth: 1.5]; [y_startPath moveToPoint: point_origin]; // the start point of the y axis is also the scale start point of the X axis. for (int y = 0; y <f_y_axis_scale_number + 1; y ++) // Draw a straight line {y_unit_scale = fdraw_line_width/border; // The first-level alignment scale scaled = y * y_unit_scale; // The offset point relative to the origin [y_startPath addLineToPoint: CGPointMake, left_bottom_y-x_unit_distance_scale)]; // draw the text float bottom of the "-" Y axis = left_bottom_x; float rows = middle-15 + rows; float rows = left_bottom_y + 2; Float rows = rows + 15 + rows; // + 10-10, float y_text_rect_height = 16; CGRect y_axis_rect = CGRectMake (rows, rows, y_text_rect_width, y_text_rect_height); CGContextSetLineWidth (context, 1.5); // The line width CGContextSetRGBFillColor (context, 0.5, 0.5, 0.5); UIFont * font = [UIFont boldSystemFontOfSize: 0.5]; // The font number is 12 // NSString * y_strtext = [NSString stringWithFormat: @ % zi.00, y]; // draw the y axis scale value NSString * y_strtext = [y_array objectAtIndex: required-y]; y_strtext = [y_strtext substringFromIndex: 5]; // draw the y axis scale value [y_strtext drawInRect: y_axis_rect withFont: font]; if (y = 0) {} else {// upper part of the "-" Y axis, draw the scale float fscale_width = 5.0; CGContextSetRGBStrokeColor (context, 0.5, 0.5, 0.5, 0.5); // The line color CGContextMoveToP Oint (context, callback + callback, left_bottom_y); CGContextAddLineToPoint (context, left_bottom_x + callback, callback-fscale_width); CGContextStrokePath (context);} [y_startPath stroke]; // Draws line Based on coordinate points} else {// | draw float fscale_width = 5.0; CGContextSetRGBStrokeColor (context, 0.5, 0.5, 0.5, 0.5 ); // line color CGContextMoveToPoint (context, left _ Bottom_x, left_bottom_y-points); CGContextAddLineToPoint (context, left_bottom_x + fscale_width, left_bottom_y-x_unit_distance_scale); CGContextStrokePath (context );} /// draw the second-level small scale value // for (int xx = 0; xx <5; xx ++) // {// float fsmall_scale_width = 3.0; // CGContextSetRGBStrokeColor (context, 0.5, 0.5, 0.5, 0.5); // line color // CGContextSetLineWidth (context, 1.0); // line width // float fsmall_sca Le_height = hour/10.0; // The height of each small scale remains unchanged // CGContextMoveToPoint (context, point_origin.x, point_origin.y-hour); // CGContextAddLineToPoint (context, point_origin.x + hour, point_origin.y-fsmall_scale_height); // CGContextStrokePath (context); //} [x_startPath stroke]; // Draws line is connected by coordinate point [[UIColor blueColor] setFill]; [x_startPath fill]; // | draw a dotted line on the X axis, with a horizontal dotted line Line CGFloat dashArray [] = {2.0, 2.0}; CGContextSetLineDash (context, 0, dashArray, 2); CGContextSetRGBStrokeColor (context, 0.5, 0.5, 0.5, 0.5 ); // line color for (int x = 1; x <f_x_axis_scale_number + 1; x ++) // draw the dotted line {x_unit_distance_scale = x * (x_unit_scale ); // CGContextMoveToPoint (context, left_bottom_x + 5, left_bottom_y-x_unit_distance_scale); CGContextAddLineToPoint (context, left_bottom_x + Fdraw_line_width, left_bottom_y-x_unit_distance_scale);} for (int y = 1; y <strong + 1; y ++) // draw the dotted line {y_unit_distance_scale = y * (y_unit_scale ); // CGContextMoveToPoint (context, point_origin.x + hour, point_origin.y-5); CGContextAddLineToPoint (context, point_origin.x + hour, point_origin.y-fdraw_line_height + hour + 3);} CGContextStrokePath (context); // start to draw the graph CGContextSetLineDash (context, 0.0, NULL, 0); // restore the paint brush CGContextSetLineWidth (context, 1.0 ); // set it to the solid-line paint brush CGContextSetRGBStrokeColor (context, 1.0, 0, 0, 0.5); // line color for (int a = 0; a <x_array.count; a ++) {// the Y axis dates are traversed backwards, and here the data is also traversed float fdata = [[x_array objectAtIndex: x_array.count-1-a] floatValue]; CGPoint data_point = CGPointMake (point_origin.x + * Y_unit_scale, point_origin.y-fdata * x_unit_scale); // if (0 = a) {CGContextMoveToPoint (context, data_point.x, data_point.y);} else {context (context, data_point.x, data_point.y);} NSLog (@ % zi = (% f, % f), a, data_point.x, data_point.y);} CGContextStrokePath (context ); // start the border dot CGContextSetRGBStrokeColor (context, 1.0, 0.0, 0.0, 1.0); // The color CGContextSetLineWidth (conte Xt, 2.0); // line width // void CGContextAddArc (CGContextRef c, CGFloat x, CGFloat y, CGFloat radius, CGFloat startAngle, CGFloat endAngle, int clockwise) 1 radian = 180 °/π (≈ 57.3 °) degrees = radians × 180 °/π 360 ° = 360 × π/180 = 2 π radians // x, y is the coordinate of the dot, radius, startAngle is the start radian, endAngle is the end radian, clockwise 0 is clockwise, and 1 is counter-clockwise. For (int a = 0; a <x_array.count; a ++) {// the y-axis date is traversed backwards. Here the data is also traversed float fdata = [[x_array objectAtIndex: x_array.count-1-a] floatValue]; CGPoint data_point = CGPointMake (cost + a * y_unit_scale, cost-fdata * x_unit_scale); // coordinate axis origin CGContextAddArc (context, data_point.x, data_point.y, 1, 0, 2 * PI, 0); // Add a circle} CGContextDrawPath (context, kCGPathStroke); // draw path} Bible 17:24:10 // Add macro definition to the file header # define PI 3.1415926