Android 平台创建 XY 图表的完整例子详解编程语言

public static void  draw_the_grid(Canvas this_g,  Vector these_labels) 
     {          
        double rounded_max = 0.0; 
        double rounded_min = 0.0; 
        double rounded_max_temp; 
        Object curElt;   
        String[] cur_elt_array; 
        int left_margin_d, right_margin_d;       
 
        if( draw_only_this_idx == -1)       
           curElt = these_labels.elementAt(0);  // default  it to 1st one if non set  
        else 
           curElt = these_labels.elementAt(draw_only_this_idx);  // now just the 1st elt 
             
        cur_elt_array = (String[])curElt; 
 
        rounded_max = get_ceiling_or_floor (Double.parseDouble(cur_elt_array[2]) , true); 
        rounded_min = get_ceiling_or_floor (Double.parseDouble(cur_elt_array[3]) , false); 
 
       // ok so now we have the max value of the set just get a cool ceiling and we go on 
        final Paint paint = new Paint();   
        paint.setTextSize(15); 
          
       left_margin_d =  getCurTextLengthInPixels(paint, Double.toString(rounded_max)); 
       //keep the position for later drawing -- leave space for the legend 
       int p_height = 170; 
       int p_width = 220; 
       int[] tmp_draw_sizes = {2 + left_margin_d, 25,p_width - 2 -  
        left_margin_d ,p_height - 25 -5}; 
       drawSizes = tmp_draw_sizes; //keep it for later processing 
          
        //with the mzrgins worked out draw the plotting grid 
       paint.setStyle(Paint.Style.FILL);  
       paint.setColor(Color.WHITE );   
         
       // Android does by coords 
       this_g.drawRect(drawSizes[0], drawSizes[1],drawSizes[0]+  
        drawSizes[2], drawSizes[1]+ drawSizes[3] , paint); 
         
       paint.setColor(Color.GRAY );        
         
        // finally draw the grid       
         
       paint.setStyle(Paint.Style.STROKE);  
       this_g.drawRect(drawSizes[0], drawSizes[1],drawSizes[0]+  
        drawSizes[2], drawSizes[1]+ drawSizes[3] , paint); 
 
           for(int i=1; i < 5 ; i++) 
           { 
               this_g.drawLine(drawSizes[0], drawSizes[1] +  
        (i * drawSizes[3] / 5), drawSizes[0] + drawSizes[2],  
        drawSizes[1] + (i * drawSizes[3] / 5), paint); 
               this_g.drawLine(drawSizes[0]+ (i * drawSizes[2] / 5),  
        drawSizes[1], drawSizes[0] + (i * drawSizes[2] / 5),  
        drawSizes[1] + drawSizes[3], paint); 
           } 
 
          // good for one value 
           print_axis_values_4_grid(this_g, cur_elt_array[1] ,  
        Double.toString(rounded_max) , Double.toString(rounded_min),  
        cur_elt_array[0] , 2 ,0 ); 
           
     }