Ant运行发生错误时

1.Problem: failed to create task or type var

Cause: The name is undefined.

Action: Check the spelling.

Action: Check that any custom tasks/types have been declared.

Action: Check that any <presetdef>/<macrodef> declarations have taken place.

作为初学者可以这样理解：因为缺少了标签库，自定义的属性不能通过编译，导入这些文件就好（resource按照自己的实际文件名）

<taskdef resource="com/.../job/task/taskdefs.xml"/>

2.如果在cmd里面打不开build.xm，注意查看根目录，是否为C：/

3.一个工程里面必须要有target,name

4.文件missing 文件扩展名没有打开