在UIActionSheet中添加UIPickerView时，iOS 7上的无效上下文错误？

我在UIActionSheet里面有一个UIPickerView，并且在SO里有很多其他人的build议：

在操作中添加UIPickerView＆abutton – 如何？

如何在UIActionSheet中添加UIPickerView

这些解决scheme在iOS 7上testing我的应用程序之前一直运行良好。它仍然可以工作，但是在运行时Xcode中出现了很多“无效的上下文0x0”警告。

错误也带来了一个不错的信息：

CGContextSetFillColorWithColor：无效的上下文0x0。 这是一个严重的错误。 此应用程序或其使用的库使用的是无效上下文，从而导致系统稳定性和可靠性的整体降级。 这个通知是礼貌的：请解决这个问题。 这将是即将到来的更新中的致命错误。

难道苹果终于想要停止这种解决scheme，还是我们可以解决或修复的东西？

Answer 1

对这种“无效的上下文0x0”警告的解决方法是使用非零标题（非零button也可以解决错误，但会导致视觉假象）初始化UIActionSheet。

 UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:@"" delegate:nil cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil]; 

然后您需要调整动作表的框架，使其在iOS7和以前的版本中正确定位（确保在showInView方法之后执行此操作）。

 CGRect newFrame = actionSheet.frame; newFrame = self.view.bounds.size.height - myCustomPicker.frame.size.height; newFrame = myCustomPicker.frame.size.height; actionSheet.frame = newFrame; 

Answer 2

正如上面的评论所指出的那样，UIActionSheet并不是被devise成小类或者其他观点的。

在苹果的更多信息：

https://developer.apple.com/library/ios/documentation/uikit/reference/UIActionSheet_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40006801-CH3-DontLinkElementID_2

一种方法是仔细观察DateCell示例代码，并改为使用UIPickerView：

https://developer.apple.com/library/ios/samplecode/DateCell/Introduction/Intro.html#//apple_ref/doc/uid/DTS40008866-Intro-DontLinkElementID_2

Answer 3

 -(void)viewDidLoad { [super viewDidLoad]; // Make Your own Action sheet myCustomeActionSheet=[[UIView alloc] initWithFrame:CGRectMake(0,self.view.frame.size.height+1,self.view.frame.size.width,215)]; myCustomeActionSheet.backgroundColor=[UIColor whiteColor]; [self.view addSubview:myCustomeActionSheet]; } 

//使用此代码打开dateselect器或UiPicker视图

 -(void)OpenActionSheet:(Boolean)isDatePickere { SelectedString=Nil; if (datepickerView) { [datepickerView removeFromSuperview]; datepickerView=Nil; } if (picker) { [picker removeFromSuperview]; picker=Nil; } if (isDatePickere) { // Add the Datepicker datepickerView= [[UIDatePicker alloc] init]; datepickerView.datePickerMode = UIDatePickerModeDateAndTime; datepickerView.minimumDate=[NSDate date]; [myCustomeActionSheet addSubview:datepickerView]; } else { // Add Picker View picker = [[UIPickerView alloc] initWithFrame:CGRectMake(0,40, 320, 216)]; picker.showsSelectionIndicator=YES; picker.dataSource = self; picker.delegate = self; [myCustomeActionSheet addSubview:picker]; } UIToolbar *tools=[[UIToolbar alloc]initWithFrame:CGRectMake(0, 0,320,40)]; tools.barStyle=UIBarStyleBlackOpaque; [myCustomeActionSheet addSubview:tools]; UIBarButtonItem *doneButton=[[UIBarButtonItem alloc]initWithTitle:@"Done" style:UIBarButtonItemStyleBordered target:self action:@selector(btnActinDoneClicked)]; doneButton.imageInsets=UIEdgeInsetsMake(200, 6, 50, 25); UIBarButtonItem *CancelButton=[[UIBarButtonItem alloc]initWithTitle:@"Cancel" style:UIBarButtonItemStyleBordered target:self action:@selector(btnActinCancelClicked)]; UIBarButtonItem *flexSpace= [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil]; NSArray *array = [[NSArray alloc]initWithObjects:CancelButton,flexSpace,flexSpace,doneButton,nil]; [tools setItems:array]; //picker title UILabel *lblPickerTitle=[[UILabel alloc]initWithFrame:CGRectMake(60,8, 200, 25)]; lblPickerTitle.text=@"Select"; lblPickerTitle.backgroundColor=[UIColor clearColor]; lblPickerTitle.textColor=[UIColor whiteColor]; lblPickerTitle.textAlignment=NSTextAlignmentCenter; lblPickerTitle.font=[UIFont boldSystemFontOfSize:15]; [tools addSubview:lblPickerTitle]; [UIView animateWithDuration:0.5 animations:^{ myCustomeActionSheet.frame=CGRectMake(0,self.view.frame.size.height-myCustomeActionSheet.frame.size.height,myCustomeActionSheet.frame.size.width,myCustomeActionSheet.frame.size.height); } completion:^(BOOL finished) { }]; } 

杂注 – 标记酒吧button行动

 -(void)btnActinDoneClicked { if (SelectedString==Nil) { SelectedString=[pickerArrayList objectAtIndex:0]; } if (datepickerView) { NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; NSLocale *posix = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]; [dateFormatter setLocale:posix]; [dateFormatter setTimeZone:[NSTimeZone systemTimeZone]]; [dateFormatter setDateFormat:@"DD/MM/yy hh:mm a"]; [selectedButton setTitle:[dateFormatter stringFromDate:datepickerView.date] forState:UIControlStateNormal]; } else [selectedButton setTitle:SelectedString forState:UIControlStateNormal]; [self performSelector:@selector(btnActinCancelClicked) withObject:nil afterDelay:0.10]; } -(void)btnActinCancelClicked { [UIView animateWithDuration:0.5 animations:^{ viewActiobSheetView.frame=CGRectMake(0,self.view.frame.size.height+1,self.view.frame.size.width,viewActiobSheetView.frame.size.height); } completion:^(BOOL finished) { [datepickerView removeFromSuperview]; [picker removeFromSuperview]; datepickerView=Nil; picker=Nil; }]; } 

pragma -mark PickerView委托

  - (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent: (NSInteger)component reusingView:(UIView *)view { UILabel *label=[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320, 40)]; label.text=[pickerArrayList objectAtIndex:row]; label.textAlignment=NSTextAlignmentCenter; label.textColor=[UIColor blackColor]; return label; } -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView; { return 1; } -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { return [pickerArrayList count]; } -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { SelectedString=[pickerArrayList objectAtIndex:row]; }