UIPickerView 替换键盘，当调用[textfield resignFirstResponce] 的时候程序就崩溃了

-(void)addPickerView

{

    UIPickerView *pickView = [[UIPickerView alloc]init];

    pickView.delegate = self;

    self.categoryFiled.inputView = pickView;

}

#pragma mark  PickerView代理

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

{

    return 1;

}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component

{

    return self.categoryArray.count;

}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

{

        return self.categoryArray[row];

}

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

{

    self.categoryFiled.text = self.categoryArray[row];

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

{

    if([self.categoryFiled  isFirstResponder])

    {

        [self.categoryFiled resignFirstResponder];

    }

}