JasperReports
这个东西，是个好东西，iReport这个东西，也是个好东西；就是iReport这个东西，给我很多启示，关于sql组件，虽最终未必可行，目前处于验证进程。
话说使用iReport＋JasperReports开发报表的曾经的尴尬，testing during development and testing on local machine, the report pdf displays well, so good job have done, but when demo in customer locale, a lot of fields cannot be displayed（不能显示了！）。
After a lot of time trying, almost every options supplied have been tried in checked way and unchecked way, the well fields displayed accordingly, I have got some ideas:
1) cannot display(不能显示), but other field with same content can display , why?
OK, the size is too small(把字符框的 大小设置大一些)，then well done.、
2）some field cannot display
process: I found these undisplayed is in header, then I copy them to footer, what's the result? display well in footer, but no display in header.
then I change the "evaluation time" from "now" to "column"
well done!
but be careful, fields valued $F cannot be column, for it cannot be displayed
3) some field cannot be display corresponding to 2)
why they cannot be displayed in both header and footer?
oh, I found most field have the "stretch with overflow" option checked, so I added, so cool
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this problem I found explation when I solved on net
iReport stretch 选项的注意
Text Field有一选项为Stretch with overflow。 作用是动态的伸展文字所占的空间。
要注意一点是Stretch是跟据Font Name的体字像数为基准进行伸展的。所以当我们输出PDF格式时要注意PDF Font Name 与Font Name是否一致。如不一致在文字量多的时候会出现少了或多了显示空间的问题
iReport Band的[Split allowed]属性
Split allowed是允许分开的意思。以页为单位，被分离出去的是Band内的所有内容。如果剩下的页面空间不够显示Band的内容。那么Band的内容会显示在下一页。
ireport有时侯不能显示数据库中数据的解决方式:
1)每一个element:设置:print when details overflow ;stretch overflow
2)字段高度不够
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all resolved, the boss smiled, and happy back from customer