滚动UIPickerView，UITableView ios8，ios9时UI被冻结

Question

I am having a view which contains a pickerView and a TextView.
The scrolling is getting stuck more and more when i present my view.
After coming 4-5 times to the view, it stuck more and more and finally UI get completely freeze while scrolling the UIPickerView. The PickerView is haveing 4 components out of which 3 has around 50 value.

Please check my PickerView code below:

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 4;
}

// The number of rows of data
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:    (NSInteger)component
{
    return [[_pickerData objectAtIndex:component] count];
}


- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:   (NSInteger)component
{
    switch (component){
       case 0:
           return 150.0;
       case 1:
           return 50.0f;
       case 2:
           return 20.0f;
       case 3:
           return 50.0f;
   }
   return 0;
}
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row    forComponent:(NSInteger)component reusingView:(UIView *)view{
   UILabel* tView = (UILabel*)view;
   if (!tView){
       tView = [[UILabel alloc] init];
       tView.font=[UIFont fontWithName:@"ArialNarrow" size:22];
       tView.textAlignment=NSTextAlignmentCenter;
       tView.text=_pickerData[component][row];
       // Setup label properties - frame, font, colors etc



      }

       return tView;
   }

Please help me.

Answer 1

if you want to show only text in pickerView then i recommended you use this method .

- (NSAttributedString*) pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component {

    NSAttributedString *str =  [[NSAttributedString alloc] initWithString:_pickerData[component][row] attributes:[NSDictionary dictionaryWithObjectsAndKeys: [UIColor whiteColor], NSForegroundColorAttributeName, [UIFont fontWithName:@"ArialNarrow" size: 22], NSFontAttributeName, nil]];
    return str;
}

instead of of using

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row    forComponent:(NSInteger)component reusingView:(UIView *)view

may be lable alloc many times.

hope it help you .

Answer 2

Thanks for the help Garry.

I have solved the issue. The issue was with the thread. I found the issue by pausing the app whenever the app freezes. On the left side, we can see the running thread. From there I caught the thread called. It was disturbing the main thread and that is why app was getting freeze.