j****n
发帖数: 107 | 1 一个dropdownlist,从数据库读取数据动态生成list item.
出现这样一个问题，无论选择了哪一个item,list.SelectedValue永远
等于排在第一的那个item值。
这是可能什么问题造成的？查了一遍又一遍，就是看不出错在哪里了。
哪位牛人来帮我看一下啊？同样的code在其它文件里都跑得好好的。
生成list的code如下：
DropDownList.Items.Clear();
foreach ( ListItem myItem in myListItems)
DropDownList.Items.Add(new ListItem(myItem.Text, myItem.Value));
DropDownList.SelectedIndex = -1;
多谢多谢! |
k****i
发帖数: 1072 | 2 In which event did you put this code?
If it's a webapp,put it in init but not page load
【在 j****n 的大作中提到】
: 一个dropdownlist,从数据库读取数据动态生成list item.
: 出现这样一个问题，无论选择了哪一个item,list.SelectedValue永远
: 等于排在第一的那个item值。
: 这是可能什么问题造成的？查了一遍又一遍，就是看不出错在哪里了。
: 哪位牛人来帮我看一下啊？同样的code在其它文件里都跑得好好的。
: 生成list的code如下：
: DropDownList.Items.Clear();
: foreach ( ListItem myItem in myListItems)
: DropDownList.Items.Add(new ListItem(myItem.Text, myItem.Value));
: DropDownList.SelectedIndex = -1;
|
j****n
发帖数: 107 | 3 Thank u for ur reply.
But it is put in an Init_DropDownList event.
【在 k****i 的大作中提到】
: In which event did you put this code?
: If it's a webapp,put it in init but not page load
|
b********s
发帖数: 12 | 4 你有没有设置dropdownlist的autopostback 为true?
【在 j****n 的大作中提到】
: Thank u for ur reply.
: But it is put in an Init_DropDownList event.
|
k****i
发帖数: 1072 | 5 I would suggest you to move it to Page OnInit() and get rid of the line
'DropDownList.SelectedIndex = -1'(actually this line have no effect on
dropdownlist)
【在 j****n 的大作中提到】
: Thank u for ur reply.
: But it is put in an Init_DropDownList event.
|
j****n
发帖数: 107 | 6 设置了，但是没有任何作用。
【在 b********s 的大作中提到】
: 你有没有设置dropdownlist的autopostback 为true?
|
j****n
发帖数: 107 | 7 Thanks, I'll try it tomorrow.
【在 k****i 的大作中提到】
: I would suggest you to move it to Page OnInit() and get rid of the line
: 'DropDownList.SelectedIndex = -1'(actually this line have no effect on
: dropdownlist)
|
G**T
发帖数: 388 | 8
I would suggest bind data to the dropdownlist in pageload
I did this in my application, never had this problem
seems somthhing is wrong at other places
I would
【在 j****n 的大作中提到】
: Thanks, I'll try it tomorrow.
|
k****i
发帖数: 1072 | 9 R u sure?
data binding in pageload will overwrite the value retrieve from viewstate and
would cause the problem that julyan encountered.Unless you use !IsPostBack
【在 G**T 的大作中提到】
:
: I would suggest bind data to the dropdownlist in pageload
: I did this in my application, never had this problem
: seems somthhing is wrong at other places
: I would
|
G**T
发帖数: 388 | 10
and
ur right, use NOT isPostBack
line
【在 k****i 的大作中提到】
: R u sure?
: data binding in pageload will overwrite the value retrieve from viewstate and
: would cause the problem that julyan encountered.Unless you use !IsPostBack
|
M******k
发帖数: 27573 | 11 en, i guess your solution is correct.
the re-initialize of dropdownlist in Page_Load
overwrite the viewstate, so he can't get selectedValue
in the event.
【在 k****i 的大作中提到】
: R u sure?
: data binding in pageload will overwrite the value retrieve from viewstate and
: would cause the problem that julyan encountered.Unless you use !IsPostBack
|
