如何在selectedindexchanged事件中使用下拉列表选定值 [英] how to use dropdown selected value inside its selectedindexchanged event
问题描述
认为这个问题几乎总结一下。
我的要求很简单,
1)填写了数据库的下拉列表。
2)根据下拉列表中的选定值,我必须显示一个表格。
即使表格可以单独显示一些下拉选项。
现在,它看起来很简单,但是我在过去2个小时就打破了我的头脑。
我有什么完成了,我已经尝试检查下拉选择索引中的dropdown.selectedvalue.text =something已更改,但它不起作用。
我知道我丢失了一些东西这里基本的。
请指导我走正确的道路。
谢谢。
Think the question pretty much sums it up.
My requirement is simple,
1)Have populated a dropdown from database.
2) Based on the selected value in dropdown, I have to show a table.
ie make the table visible for some drop down selections alone.
Now, it looks pretty simple, but Iam breaking my head for the past 2 hours on this.
What I have done is, I have tried checking the dropdown.selectedvalue.text="something" inside the dropdown selected index changed, but it doesnt work.
I know Iam missing something basic here.
Pls guide me in the right path.
Thanks.
推荐答案
尝试 DropDownList.SelectedIndex属性 [ ^ ] - 应该是一个盯着选定的指南更改。
Try DropDownList.SelectedIndex Property [^] - should be a guide to get stared with selected change.
下面的代码需要写在下拉列表的selectedindexchanged事件中。
The below code needs to be written in the selectedindexchanged event of the dropdown.
ComboBox cmb = (ComboBox)sender;
if (cmb.SelectedValue.ToString().Equals("Something")
{
//Do Something
}
希望这会有所帮助。
Hope this helps.
基于这个事实TS提到填充数据库的下拉列表,SelectedValue实际上不太可能是一个字符串。
很可能,ValueMember绑定到数据库中记录的Id,DisplayMember必然会一些说明。
Based on the fact that the TS mentioned populating the dropdown from the database, it's very unlikely that SelectedValue is actually a string.
More than likely, ValueMember is bound to the Id of the record in the database, DisplayMember is bound to some Description.
object val = ((ComboBox)sender).SelectedValue; // returns the Id
string txt = ((ComboBox)sender).SelectedText; // returns the text visible on the screen for the selected item
object item = ((ComboBox)sender).SelectedItem; // returns the entire object from the datasource you have bound to the combobox
根据您的需要,使用其中任何一个来检索/显示更多数据。
Depending on your needs, use any of these to retrieve/show further data.
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