Brother in ASP. NET wants to drop down the list box and want to raise an event when clicking on an option, please give p

水蓝的牧师

Send the code to see it`
Then we look better

1区卡扎克lm

The cause of the problem has been found, thank you for your guidance

alcards

The cause of the problem is found, thank you for your guidance

what reason

jesenjun

what reason

marksgu

Observe. .