通过 didSelectRow UIPickerView 传递托管对象数据
我对如何通过 didSelectRow UIPickerView 操作传递获取的托管对象数据有点迷失。
在上一个视图中，我像这样传递了 CalcInfo 对象：
CalcInfo *calc = (CalcInfo *)[_calcInfos objectAtIndex:indexPath.row];
self.myPageOneViewController.calcInfos = calc;
我成功地将 calcInfos.attribute 用于所有 IBAction:(id)sender 按钮，但 pickerView 无法获取/使用数据。 updateLabel 操作始终将 calcInfos.attribute 设为 NULL。这是我的一些代码
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
[self updateLabel];
}
- (void)updateLabel {
double stdrate = [calcInfos.infusionstd doubleValue];
double lowrate = [calcInfos.infusionlow doubleValue];
if (calcInfos.infusionlow == NULL) {
NSLog(@"It's null");
}
}
非常感谢您的帮助！
I'm a bit lost on how to pass my fetched managed object data through a didSelectRow UIPickerView action.
On the previous view, I passed the CalcInfo object like this:
CalcInfo *calc = (CalcInfo *)[_calcInfos objectAtIndex:indexPath.row];
self.myPageOneViewController.calcInfos = calc;
I was successfully able to use calcInfos.attribute for all my IBAction:(id)sender buttons, but the pickerView isn't able to fetch / use the data. The updateLabel action always has calcInfos.attribute as NULL. Here's a bit of my code
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
[self updateLabel];
}
- (void)updateLabel {
double stdrate = [calcInfos.infusionstd doubleValue];
double lowrate = [calcInfos.infusionlow doubleValue];
if (calcInfos.infusionlow == NULL) {
NSLog(@"It's null");
}
}
Your help is much appreciated!
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选择器视图是一个具有自己的硬连线控制器的子视图。它返回在其委托消息“didSelectRow:inComponent”中选取的行和列/组件。
您需要将该信息传递给您的 updateLabel 方法，以便您可以将 pickerview 选择与您的托管对象相关联。目前，该方法根本不执行任何操作。
The picker view is a subview with its own hardwired controller. It returns the row and column/component picked in its delegate message `didSelectRow:inComponent'.
You need to pass that info along to your
updateLabelmethod so that you can relate the pickerview selection to your managed objects. Right now, the method does nothing at all.