問題描述
Flex Combobox 奇怪的問題 (Flex Combobox strange problem)
I am facing a strange problem with the combobox in Flex. In the following code :
public function rollCombo(cmb:ComboBox,value:String):void
{
if(value=='') return;
var i:int=0;
cmb.selectedIndex = 0;
var dp1:XMLListCollection = (XMLListCollection(cmb.dataProvider);
trace(value);
while(dp1[i]!=value && i<dp1.length)
cmb.selectedIndex = ++i;
cmb.validateNow();
cmb.validateDisplayList();
trace(cmb.selectedLabel);
}
in an example case, at the end of the execution of the function, i is 7, and cmb.selectedLabel is "xyz"(according to the trace output), but the label displayed in the combobox is a different one.
Also, this is rather unpredictable. It happens sometimes and not always.
參考解法
方法 1:
The last selectedIndex is out of range, because you use pre-incrementation. Which means i becomes dp1.length before the test, and it's assigned to selectedIndex too. That might explain the weird behavior. You'll probably want to use post-incrementation.
Also. The only thing that gets executed in that while looks to be
cmb.selectedIndex = ++i;
I don't know if that's what you wanted, but you might need some "{}" there.