第二章第二节课图片完全显示不了，N种报错
我的代码：
浏览器显示一大堆的报错
Notice: Undefined offset: 0 in G:\wamp\www\jpgraph\jpgraph-3.5.0b1\src\jpgraph.php on line 5515
Notice: Undefined offset: 0 in G:\wamp\www\jpgraph\jpgraph-3.5.0b1\src\jpgraph.php on line 5480
Notice: Undefined offset: 0 in G:\wamp\www\jpgraph\jpgraph-3.5.0b1\src\jpgraph.php on line 5515
Notice: Undefined offset: 0 in G:\wamp\www\jpgraph\jpgraph-3.5.0b1\src\jpgraph.php on line 5480
Notice: Undefined offset: 0 in G:\wamp\www\jpgraph\jpgraph-3.5.0b1\src\jpgraph_line.php on line 209
浏览器最下方提示：
JpGraph Error: HTTP headers have already been sent.
Caused by output from file jpgraph.php at line 5480.
Explanation:
HTTP headers have already been sent back to the browser indicating the data as text before the library got a chance to send it's image HTTP header to this browser. This makes it impossible for the library to send back image data to the browser (since that would be interpretated as text by the browser and show up as junk text).
Most likely you have some text in your script before the call to Graph::Stroke(). If this texts gets sent back to the browser the browser will assume that all data is plain text. Look for any text, even spaces and newlines, that might have been sent back to the browser.
For example it is a common mistake to leave a blank line before the opening "<?php".
