字符串截取问题，在线等！ ( 积分: 50 )

<input type="hidden" name="__VIEWSTATE" value="dDwtMTg4MjY4NzEwMS1iVNgFcg==" />
我现在想截取.net页面中ViewState的value中的值，如上。

但是我用 GetStr(TempStr,'__VIEWSTATE" value="', '=" />'); 就可以截取的到
可是把结束字符中的等号去掉就不行了，是什么原因？该怎么解决呢？

我使用的截取函数是这样：
function GetStr(StrSource, StrBegin, StrEnd:String): String;
var
in_star, in_end : integer;
begin
in_star := AnsiPos(strbegin, strsource) + length(strbegin);
in_end := AnsiPos(strend, strsource);
result := Copy(strsource, in_star, in_end-in_star);
end;

没明白你的意思！

你是说
GetStr(TempStr,'__VIEWSTATE" value="', '" />');
这样？？

可以截取啊

GetStr(TempStr,'__VIEWSTATE" value="', '" />');
是这样，但是ViewState值很长的时候，什么也截不到，但是结束符再多个字符又可以截到，晕！

你给一个取不到的值！

我看看！！

这个：
<input type="hidden" name="__VIEWSTATE" value="dDwtMTg4MjY4NzEwMzt0PHA8bDxVc2VyRmlsZVZpcnR1YWxQYXRoO1VzZXJGaWxlUGh5c2ljYWxQYXRoO01heFNwYWNlU2l6ZTtVcGRhdGVJbWFnZVNpemU7UGFnZUluZGV4O1BhZ2VOdW1iZXI7VXNlclRvdGFsRmlsZVNpemU7PjtsPC9Vc2VyRmlsZXMveC94aS94aWEveGlhb2tla2UuaXQuY29tLmNuL2ZpbGVzLztcXFxcMjE5LjIzOS45NC40NlxcaXRfaG9tZVxceFxceGlcXHhpYVxceGlhb2tla2UuaXQuY29tLmNuXFxmaWxlc1xcO2k8NTEwNjU+OzIwMDA7aTwxPjtpPDM+Ozk5MDk7Pj47bDxpPDE+Oz47bDx0PHA8bDxlbmN0eXBlOz47bDxtdWx0aXBhcnQvZm9ybS1kYXRhOz4+O2w8aTwxPjtpPDM+O2k8NT47aTwxNT47PjtsPHQ8QDA8cDxwPGw8RGF0YUtleXM7XyFJdGVtQ291bnQ7PjtsPGw8PjtpPDQwPjs+Pjs+Ozs7Ozs7Ozs+O2w8aTwwPjtpPDE+O2k8Mj47aTwzPjtpPDQ+O2k8NT47aTw2PjtpPDc+O2k8OD47aTw5PjtpPDEwPjtpPDExPjtpPDEyPjtpPDEzPjtpPDE0PjtpPDE1PjtpPDE2PjtpPDE3PjtpPDE4PjtpPDE5PjtpPDIwPjtpPDIxPjtpPDIyPjtpPDIzPjtpPDI0PjtpPDI1PjtpPDI2PjtpPDI3PjtpPDI4PjtpPDI5PjtpPDMwPjtpPDMxPjtpPDMyPjtpPDMzPjtpPDM0PjtpPDM1PjtpPDM2PjtpPDM3PjtpPDM4PjtpPDM5Pjs+O2w8dDw7bDxpPDA+Oz47bDx0PEA8MjAwNzIyNjE3MjMyNC5qcGc7eGlhb2tla2U7MjAwNzIyNjE3MjMyNC5qcGc7eGlhb2tla2U7MjAwNzIyNjE3MjMyNF9zbWFsbC5qcGc7ZmFjZTJrZWtlLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDcyMTIxNzQ1MzkuanBnO3hpYW9rZWtlOzIwMDcyMTIxNzQ1MzkuanBnO3hpYW9rZWtlOzIwMDcyMTIxNzQ1Mzlfc21hbGwuanBnO21vdXNoYTEuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNzIxMjE3NDYxLmpwZzt4aWFva2VrZTsyMDA3MjEyMTc0NjEuanBnO3hpYW9rZWtlOzIwMDcyMTIxNzQ2MV9zbWFsbC5qcGc7bW91c2hhMi5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA3MjEyMTc0NjE3LmpwZzt4aWFva2VrZTsyMDA3MjEyMTc0NjE3LmpwZzt4aWFva2VrZTsyMDA3MjEyMTc0NjE3X3NtYWxsLmpwZzttb3VzaGEzLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDcyMTIxNzQ2MjcuanBnO3hpYW9rZWtlOzIwMDcyMTIxNzQ2MjcuanBnO3hpYW9rZWtlOzIwMDcyMTIxNzQ2Mjdfc21hbGwuanBnO21vdXNoYTQuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNzI3MTEzMTcuanBnO3hpYW9rZWtlOzIwMDcyNzExMzE3LmpwZzt4aWFva2VrZTsyMDA3MjcxMTMxN19zbWFsbC5qcGc7QXZyaWwuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNzEyOTE2NDU0LmpwZzt4aWFva2VrZTsyMDA3MTI5MTY0NTQuanBnO3hpYW9rZWtlOzIwMDcxMjkxNjQ1NF9zbWFsbC5qcGc7aWxvdmV3Zy5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA3MTE1MTgxMjAuanBnO3hpYW9rZWtlOzIwMDcxMTUxODEyMC5qcGc7eGlhb2tla2U7MjAwNzExNTE4MTIwX3NtYWxsLmpwZztiMS5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2MTExMDIxNTMxMy5qcGc7eGlhb2tla2U7MjAwNjExMTAyMTUzMTMuanBnO3hpYW9rZWtlOzIwMDYxMTEwMjE1MzEzX3NtYWxsLmpwZztzc2JfYmlnLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDYxMTYyMjIyMTkuanBnO3hpYW9rZWtlOzIwMDYxMTYyMjIyMTkuanBnO3hpYW9rZWtlOzIwMDYxMTYyMjIyMTlfc21hbGwuanBnO2hvbWUyLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDYxMTIyMjExNTguanBnO3hpYW9rZWtlOzIwMDYxMTIyMjExNTguanBnO3hpYW9rZWtlOzIwMDYxMTIyMjExNThfc21hbGwuanBnO2FkZG9uZS5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2MTAyODIyNTEuanBnO3hpYW9rZWtlOzIwMDYxMDI4MjI1MS5qcGc7eGlhb2tla2U7MjAwNjEwMjgyMjUxX3NtYWxsLmpwZztob21lX2hlbHBlci5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2MTAyODIxMjgyMS5qcGc7eGlhb2tla2U7MjAwNjEwMjgyMTI4MjEuanBnO3hpYW9rZWtlOzIwMDYxMDI4MjEyODIxX3NtYWxsLmpwZztoZWxwZXIuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjEwMjEyMzE1MS5qcGc7eGlhb2tla2U7MjAwNjEwMjEyMzE1MS5qcGc7eGlhb2tla2U7MjAwNjEwMjEyMzE1MV9zbWFsbC5qcGc7YzRkMy5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2MTAyMTE0NDU1Ni5qcGc7eGlhb2tla2U7MjAwNjEwMjExNDQ1NTYuanBnO3hpYW9rZWtlOzIwMDYxMDIxMTQ0NTU2X3NtYWxsLmpwZztjNGQxLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDYxMDIxMTQ0NjEzLmpwZzt4aWFva2VrZTsyMDA2MTAyMTE0NDYxMy5qcGc7eGlhb2tla2U7MjAwNjEwMjExNDQ2MTNfc21hbGwuanBnO2M0ZDIuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjkyNTIyNDEzMy5qcGc7eGlhb2tla2U7MjAwNjkyNTIyNDEzMy5qcGc7eGlhb2tla2U7MjAwNjkyNTIyNDEzM19zbWFsbC5qcGc7eGJveDM2MC5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2OTI1MjIzMzM1LmpwZzt4aWFva2VrZTsyMDA2OTI1MjIzMzM1LmpwZzt4aWFva2VrZTsyMDA2OTI1MjIzMzM1X3NtYWxsLmpwZzt4Ym94LmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY5MjMyMjI0MzMuanBnO3hpYW9rZWtlOzIwMDY5MjMyMjI0MzMuanBnO3hpYW9rZWtlOzIwMDY5MjMyMjI0MzNfc21hbGwuanBnO2Rpc3BsYXkuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjk5MjAxMjM0LmpwZzt4aWFva2VrZTsyMDA2OTkyMDEyMzQuanBnO3hpYW9rZWtlOzIwMDY5OTIwMTIzNF9zbWFsbC5qcGc7Ymx1ZWlkZWEuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjk1MTIyMzIuanBnO3hpYW9rZWtlOzIwMDY5NTEyMjMyLmpwZzt4aWFva2VrZTsyMDA2OTUxMjIzMl9zbWFsbC5qcGc7dG91a3VpMTEuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjk0MjAxMDE3LmpwZzt4aWFva2VrZTsyMDA2OTQyMDEwMTcuanBnO3hpYW9rZWtlOzIwMDY5NDIwMTAxN19zbWFsbC5qcGc7dG91a3VpLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY4MjQyMDUxMy5qcGc7eGlhb2tla2U7MjAwNjgyNDIwNTEzLmpwZzt4aWFva2VrZTsyMDA2ODI0MjA1MTNfc21hbGwuanBnO2J0X21lZGlhX2xvZ28uanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjgxMjExMzA0NS5qcGc7eGlhb2tla2U7MjAwNjgxMjExMzA0NS5qcGc7eGlhb2tla2U7MjAwNjgxMjExMzA0NV9zbWFsbC5qcGc7cmVkLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY4MjIxMDEzLmpwZzt4aWFva2VrZTsyMDA2ODIyMTAxMy5qcGc7eGlhb2tla2U7MjAwNjgyMjEwMTNfc21hbGwuanBnO3dhbGxwYXBlci5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2ODIxNTE0MzkuanBnO3hpYW9rZWtlOzIwMDY4MjE1MTQzOS5qcGc7eGlhb2tla2U7MjAwNjgyMTUxNDM5X3NtYWxsLmpwZztrZWtlX2ZhY2UyMi5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NzMwMTc3MTQuanBnO3hpYW9rZWtlOzIwMDY3MzAxNzcxNC5qcGc7eGlhb2tla2U7MjAwNjczMDE3NzE0X3NtYWxsLmpwZztmYWNlMi5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NzI4MTE1OTIzLmpwZzt4aWFva2VrZTsyMDA2NzI4MTE1OTIzLmpwZzt4aWFva2VrZTsyMDA2NzI4MTE1OTIzX3NtYWxsLmpwZztjYXJkLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY3MjYxMzM3NDYuanBnO3hpYW9rZWtlOzIwMDY3MjYxMzM3NDYuanBnO3hpYW9rZWtlOzIwMDY3MjYxMzM3NDZfc21hbGwuanBnO2tla2VfbG9nby5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NzExMjIxODkuanBnO3hpYW9rZWtlOzIwMDY3MTEyMjE4OS5qcGc7eGlhb2tla2U7MjAwNjcxMTIyMTg5X3NtYWxsLmpwZztpY29uLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY2MjkyMTM3NS5qcGc7eGlhb2tla2U7MjAwNjYyOTIxMzc1LmpwZzt4aWFva2VrZTsyMDA2NjI5MjEzNzVfc21hbGwuanBnOzEyMzQ1Ni5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NjIyMTUwMjcuanBnO3hpYW9rZWtlOzIwMDY2MjIxNTAyNy5qcGc7eGlhb2tla2U7MjAwNjYyMjE1MDI3X3NtYWxsLmpwZzszYWEuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjYyMjE0NTk0My5qcGc7eGlhb2tla2U7MjAwNjYyMjE0NTk0My5qcGc7eGlhb2tla2U7MjAwNjYyMjE0NTk0M19zbWFsbC5qcGc7NGFhLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY2MjIxNTAxMC5qcGc7eGlhb2tla2U7MjAwNjYyMjE1MDEwLmpwZzt4aWFva2VrZTsyMDA2NjIyMTUwMTBfc21hbGwuanBnOzJhYS5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NjIyMTQ0MTIzLmpwZzt4aWFva2VrZTsyMDA2NjIyMTQ0MTIzLmpwZzt4aWFva2VrZTsyMDA2NjIyMTQ0MTIzX3NtYWxsLmpwZzsxYWEuanBnOz47Oz47Pj47dDw7bDxpPDA+Oz47bDx0PEA8MjAwNjYxNDEwNjIzLmpwZzt4aWFva2VrZTsyMDA2NjE0MTA2MjMuanBnO3hpYW9rZWtlOzIwMDY2MTQxMDYyM19zbWFsbC5qcGc7VUkyLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY2MTQxMDI1MC5KUEc7eGlhb2tla2U7MjAwNjYxNDEwMjUwLkpQRzt4aWFva2VrZTsyMDA2NjE0MTAyNTBfc21hbGwuSlBHO1VJLkpQRzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY2MTQ5NTc1Ny5qcGc7eGlhb2tla2U7MjAwNjYxNDk1NzU3LmpwZzt4aWFva2VrZTsyMDA2NjE0OTU3NTdfc21hbGwuanBnO3R0Mi5qcGc7Pjs7Pjs+Pjt0PDtsPGk8MD47PjtsPHQ8QDwyMDA2NjE0OTM3OC5qcGc7eGlhb2tla2U7MjAwNjYxNDkzNzguanBnO3hpYW9rZWtlOzIwMDY2MTQ5Mzc4X3NtYWxsLmpwZztmYWNlLmpwZzs+Ozs+Oz4+O3Q8O2w8aTwwPjs+O2w8dDxAPDIwMDY2MTQ5MTI0Ny5KUEc7eGlhb2tla2U7MjAwNjYxNDkxMjQ3LkpQRzt4aWFva2VrZTsyMDA2NjE0OTEyNDdfc21hbGwuSlBHO0hPTUUuSlBHOz47Oz47Pj47Pj47dDxwPGw8VmlzaWJsZTs+O2w8bzxmPjs+Pjs7Pjt0PDtsPGk8MD47PjtsPHQ8O2w8aTwxPjtpPDM+O2k8NT47aTw3PjtpPDk+O2k8MTU+Oz47bDx0PHA8cDxsPFRleHQ7PjtsPDg1Oz4+Oz47Oz47dDxwPHA8bDxUZXh0Oz47bDwxOz4+Oz47Oz47dDxwPHA8bDxUZXh0Oz47bDwzOz4+Oz47Oz47dDxwPHA8bDxFbmFibGVkOz47bDxvPGY+Oz4+Oz47Oz47dDxwPHA8bDxFbmFibGVkOz47bDxvPGY+Oz4+Oz47Oz47dDxwPGw8ZGlzYWJsZWQ7PjtsPDs+Pjs7Pjs+Pjs+Pjt0PHA8bDxpbm5lcmh0bWw7PjtsPOaCqOWPr+eUqOeahOaAu+epuumXtOS4ujUxMDY1S++8jOebruWJjeW3suS9v+eUqDk5MDlLOz4+Ozs+Oz4+Oz4+Oz7R3DxiwaIDUafXh6hAUOlTiK0x6A==" />

晕啊

可以取道！

我是先get一个页面从里面取，例如：
idHTTP:= TidHTTp.create(nil);
try
TempStr := idhttp.Get('http://bbs.it.com.cn/ShowPost.aspx?TopicID=73450');
ViewState:= GetStr(TempStr, '__VIEWSTATE" value="','" />');
这个页面的ViewState值比较短，可是还是取不到，哭.......

function GetStr(StrSource, StrBegin, StrEnd:String): String;
var
in_star, in_end : integer;
begin
in_star := AnsiPos(strbegin, strsource) + length(strbegin);
Delete(StrSource, 1,In_Star-1);
in_end := AnsiPos(strend, strsource);
result := Copy(strsource, 1, in_end);
end;

改成差不多上面这样就可以了，理由很简单，你的结束字符在开始字符之前还存在，根据你提供的网址，可以得到开始字符是9百多，而结束的位置是8百多，试想
Copy(strsource, 900, -100)能取到什么字符呢？

顺便建议一句，下次碰到问题要追踪一下代码，这一跟踪不就出来了，结束位置比起始位置小，显然取不到字符嘛。

而且也说明一个问题，考虑欠妥当，试想 " />' 的短字符串，在整个网页中出现的频率是很高的。这也就是你说的，再加两等号就能取到的原因。

非常感谢levi的热心回答，原来是这样，问题解决了，哈哈，好开心呀[]