如何检测UIPickerView的变化？

Question

我想检测UIPickerView值的变化.

如果UIPickerView响应addTarget我使用了这样的代码:

-(void) valueChange:(id)sender {
change = YES;

} 

UIPickerView *questionPicker = [[UIPickerView alloc] init]; 
[questionPicker addTarget:self action:@selector(valueChange:) forControlEvents:UIControlEventValueChanged];

我怎么能以正确的方式做同样的事情呢？

Answer 1

如果你看一下UIPickerViewDelegate它有:

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

只需设置您的选择器视图委托并实现它.

Answer 2

UIPickerViewDelegate 具有 pickerView:didSelectRow:inComponent: