我下了个C# Hooks For RRDtool，想学习下rrdtool是如何使用的
在运行中发现一个怪事，如果按照给的示例运行代码，生成的speed.png图中就画有红线；
代码如下:
RRD rrd1 = new RRD("test.rrd", 920804400);
rrd1.addDS(new DS("speed", DS.TYPE.COUNTER, 600, DS.U, DS.U)) ;
rrd1.addRRA(new RRA(RRA.CF.AVERAGE, 0.5, 1, 24));
rrd1.addRRA(new RRA(RRA.CF.AVERAGE, 0.5, 6, 10));
rrd1.create(true);
rrd1.update(920804700, new string[] { "12345" });
rrd1.update(920805000, new object[] { 12357 });
rrd1.update(920805300, new object[] { 12363 });
rrd1.update(920805600, new object[] { 12363 });
rrd1.update(920805900, new object[] { 12363 });
rrd1.update(920806200, new object[] { 12373 });
rrd1.update(920806500, new object[] { 12383 });
rrd1.update(920806800, new object[] { 12393 });
rrd1.update(920807100, new object[] { 12399 });
rrd1.update(920807400, new object[] { 12405 });
rrd1.update(920807700, new object[] { 12411 });
rrd1.update(920808000, new object[] { 12415 });
rrd1.update(920808300, new object[] { 12420 });
rrd1.update(920808600, new object[] { 12422 });
rrd1.update(920808900, new object[] { 12423 });
Console.WriteLine("Graph test # 1");
GRAPH gr1 = new GRAPH("speed.png", "920804400", "920808000");
gr1.addDEF(new DEF("myspeed", "test.rrd", "speed", RRA.CF.AVERAGE));
gr1.addGELEM(new LINE(2, "myspeed", Color.Red));
gr1.graph();
但是如果rrd1.update加载的是我从网卡采集出来的数据，生成的图片中什么都没有
代码如下：
RRD rrd1 = new RRD("test.rrd", 1376018336);
rrd1.addDS(new DS("speed", DS.TYPE.COUNTER, 600, DS.U, DS.U)) ;
rrd1.addRRA(new RRA(RRA.CF.AVERAGE, 0.5, 1, 24));
rrd1.addRRA(new RRA(RRA.CF.AVERAGE, 0.5, 6, 10));
rrd1.create(true);
rrd1.update(1376018456, new string[] { "69294224" });
rrd1.update(1376018576, new object[] { 69417727 });
rrd1.update(1376018696, new object[] { 69536985 });
rrd1.update(1376018816, new object[] { 69719206 });
rrd1.update(1376018936, new object[] { 69842372 });
rrd1.update(1376019056, new object[] { 70180867 });
Console.WriteLine("Graph test # 1");
GRAPH gr1 = new GRAPH("speed.png", "1376018336", "1376019056");
gr1.addDEF(new DEF("myspeed", "test.rrd", "speed", RRA.CF.AVERAGE));
gr1.addGELEM(new LINE(2, "myspeed", Color.Red));
gr1.graph();
反复测试都是这个结果
劳烦有过rrdtool经验的大虾详解讲解下，谢谢
