這里是從dataset里的數據生成曲線圖.
我的dataset是從表sendrec里讀取的數據,分別有id,sendid(訂單號),sendtime(記錄時間),sendnum(單位時間發送量/我這里是五分鐘)幾個字段
過程如下:
public void draw(page page,dataset ds,int tnum){}
其中page是用來傳遞引用這個過程的頁面,這樣讓頁面是jpg方式直接向客戶端輸出生成的曲線圖.
ds就是取出來的數據集了
tnum只是我這里要用到的一個參數,不想讓這個類去接觸讀取過程,所以把訂單的總量直接取出后傳遞給它的.
using system;
using system.data;
using system.configuration;
using system.web;
using system.web.security;
using system.web.ui;
using system.web.ui.webcontrols;
using system.web.ui.htmlcontrols;
using system.drawing.drawing2d;
using system.drawing.imaging;
using system.drawing;
using system.io;
public class imgdraw
{
    public imgdraw()
    {
        
    }
    public void draw(page page,dataset ds,int tnum)
    {
        //取得記錄數量
        int count = ds.tables[0].rows.count;
        //記算圖表寬度
        int wd = 80 + 20 * (count - 1);
        //設置最小寬度為800
        if (wd < 800) wd = 800;
        //生成bitmap對像
        bitmap img=new bitmap(wd,400);
        //生成繪圖對像
        graphics g = graphics.fromimage(img);
        //定義黑色畫筆
        pen bp = new pen(color.black);
        //定義紅色畫筆
        pen rp = new pen(color.red);
        //定義銀灰色畫筆
        pen sp = new pen(color.silver);
        //定義大標題字體
        font bfont = new font("arial", 12, fontstyle.bold);
        //定義一般字體
        font font = new font("arial", 6);
        //定義大點的字體
        font tfont = new font("arial", 9);
        //繪制底色
        g.drawrectangle(new pen(color.white, 400), 0, 0, img.width, img.height);
        //定義黑色過渡型筆刷
        lineargradientbrush brush = new lineargradientbrush(new rectangle(0, 0, img.width, img.height), color.black, color.black, 1.2f, true);
        //定義藍色過渡型筆刷
        lineargradientbrush bluebrush = new lineargradientbrush(new rectangle(0, 0, img.width, img.height), color.blue, color.blue, 1.2f, true);
        //繪制大標題
        g.drawstring(ds.tables[0].rows[0]["sendid"].tostring() + "號訂單發送情況曲線圖", bfont, brush, 40, 5);
        //取得當前發送量
        int nums=0;
        for (int i = 0; i < count; i++)
        {
            nums+=convert.toint32(ds.tables[0].rows[i]["sendnum"]);
        }
        //繪制信息簡報
        string info="訂單發送時間:"+ds.tables[0].rows[0]["sendtime"].tostring()+"  曲線圖生成時間:"+datetime.now.tostring()+"  訂單總量:"+tnum.tostring()+"  當前發送總量:"+nums.tostring();
        g.drawstring(info, tfont, bluebrush, 40, 25);
        //繪制圖片邊框
        g.drawrectangle(bp, 0, 0, img.width - 1, img.height - 1);
        //繪制豎坐標線       
        for (int i = 0; i < count; i++)
        {
            g.drawline(sp, 40+20 * i, 60, 40+20 * i, 360);
        }
        //繪制時間軸坐標標簽
        for (int i = 0; i < count; i+=2)
        {
            string st = convert.todatetime(ds.tables[0].rows[i]["sendtime"]).tostring("hh:mm");
            g.drawstring(st, font, brush, 30 + 20 * i, 370);
        }
        //繪制橫坐標線
        for (int i = 0; i < 10; i++)
        {
            g.drawline(sp, 40, 60+30*i, 40+20*(count-1), 60+30*i);
            int s = 2500 - 50 * i * 5;
            //繪制發送量軸坐標標簽
            g.drawstring(s.tostring(), font, brush, 10, 60 + 30 * i);
        }
        
        //繪制豎坐標軸
        g.drawline(bp, 40, 55, 40, 360);
        //繪制橫坐標軸
        g.drawline(bp, 40, 360, 45 + 20 * (count - 1), 360);
        //定義曲線轉折點
        point[] p = new point[count];
        for (int i = 0; i < count; i++)
        {
            p[i].x = 40 + 20 * i;
            p[i].y = 360- convert.toint32(ds.tables[0].rows[i]["sendnum"]) / 5*3/5;
        }
        //繪制發送曲線
        g.drawlines(rp, p);
        for (int i = 0; i < count; i++)
        {
            //繪制發送記錄點的發送量
            g.drawstring(ds.tables[0].rows[i]["sendnum"].tostring(), font, bluebrush, p[i].x, p[i].y - 10);
            //繪制發送記錄點
            g.drawrectangle(rp, p[i].x - 1, p[i].y - 1, 2, 2);
        }
        //繪制豎坐標標題
        g.drawstring("發送量", tfont, brush, 5, 40);
        //繪制橫坐標標題
        g.drawstring("發送時間", tfont, brush, 40, 385);
        //保存繪制的圖片
        memorystream stream = new memorystream();
        img.save(stream, imageformat.jpeg);
        //圖片輸出
        page.response.clear();
        page.response.contenttype = "image/jpeg";
        page.response.binarywrite(stream.toarray());
    }
}
嘿嘿!發表這個,就是一個圖片的繪制方法的記錄了.這里面還有很多不當之久,望指教. 
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