Ios 当ViewDid出现时，如何调用pickerview的委托？
当视图出现时，我需要完全调用pickerview中最后选定的行！我的Ios 当ViewDid出现时，如何调用pickerview的委托？,ios,objective-c,cocoa-touch,delegates,uipickerview,Ios,Objective C,Cocoa Touch,Delegates,Uipickerview,当视图出现时，我需要完全调用pickerview中最后选定的行！我的视图中有此代码显示它将动画显示到最后选定的行，但它不会真正调用代理，并且我行中的NSLog不会打印，除非触摸我的选取器并重新选择它们 我该怎么做 - (void)viewDidAppear:(BOOL)animated { NSUserDefaults *pickerViewSelectionDefaults = [NSUserDefaults standardUserDefaults]; [tasbeehPicker se
视图中有此代码显示代理NSLog- (void)viewDidAppear:(BOOL)animated {
NSUserDefaults *pickerViewSelectionDefaults = [NSUserDefaults standardUserDefaults];
[tasbeehPicker selectRow:[pickerViewSelectionDefaults integerForKey:@"picker"]
inComponent:0 animated:YES];
[pickerViewSelectionDefaults synchronize];
[UIPicker reloadAllComponents];
NSLog(@"Last selcted row was %d ",[[NSUserDefaults standardUserDefaults] integerForKey:@"picker"]);
}
通过代码更新选择器时不应调用委托。仅当用户与选择器交互时，才会调用委托。如果两种情况下都需要调用相同的代码，请执行以下操作：
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[myPicker selectRow:4 inComponent:0 animated:animated];
[self handlePickerSelection:myPicker];
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
[self handledPickerSelection:pickerView];
}
- (void)handlePickerSelection:(UIPickerView *)pickerView {
// process selection
}
通过代码更新选择器时不应调用委托。仅当用户与选择器交互时，才会调用委托。如果两种情况下都需要调用相同的代码，请执行以下操作：
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[myPicker selectRow:4 inComponent:0 animated:animated];
[self handlePickerSelection:myPicker];
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
[self handledPickerSelection:pickerView];
}
- (void)handlePickerSelection:(UIPickerView *)pickerView {
// process selection
}
您可以从下面的方法中获取所选行 在ViewDidDisplay中添加此代码
int index = [pickerViewObject selectedRowInComponent:0];
[pickerViewObject selectRow:index inComponent:0 animated:YES];
int index = [pickerViewObject selectedRowInComponent:0];
现在将此索引值保存在NSUserDefaults中。您可以从下面的方法中获取所选行 在ViewDidDisplay中添加此代码
int index = [pickerViewObject selectedRowInComponent:0];
[pickerViewObject selectRow:index inComponent:0 animated:YES];
int index = [pickerViewObject selectedRowInComponent:0];
现在将此索引值保存在NSUserDefaults中。不要用与xcode无关的
xcodeuipickerviewxcodeuipickerview行NSUserDefaultNSUserDefaultssynchronizeNSUserDefaultNSUserDefaults行NSUserDefaultNSUserDefaultssynchronizeNSUserDefaultNSUserDefaults