工作几天后，UITextField.inputView突然不弹出UIPickerView

Question

I'm working on my first app ever (quite a learning experience). Today after studying and reading and trial/error I was able to programmatically create and fill a UIPickerView and have it pop up when I select the appropriate UITextField.

I have my main ViewController with a UITableView already setup and populated with some JSON data. Above the UITableView I added a subview (called FilterView below) I want to house some controls to filter my UITableView (I'm not so sure the subview isn't part of the problem). After creating my UIPickerView in code (didn't use Storyboard) and filling it with some data, and setting my UITextField in my subview with the appropriate .inputView (to trigger the UIPickerView to appear) I had everything working the way I wanted and was about to move on to setting precedents for filtering my `UITableView.

So here is my layout of my views with textfields in storyboard:

You'll notice I have my main view (called View ), a subview with all my controls in it (called FilterView ), and my UITableView below all that. Then I created my three picker UIPickerViews in my viewDidLoad , set the DataSource and Delegate and set the inputView to the textfields I wanted:

_voltagePickerView =    [[UIPickerView alloc] initWithFrame:CGRectZero];
[_voltagePickerView setDataSource: self];
[_voltagePickerView setDelegate: self];
_voltagePickerView.showsSelectionIndicator = YES;
_voltageFilterField.inputView = _voltagePickerView;

//same for other 3

And of course the UIPickerView properties are in my ViewController.h file, along with the Outlets for the UITextField s:

@property (strong, nonatomic) UIPickerView *rpmPickerView;
@property (strong, nonatomic) UIPickerView *voltagePickerView;
@property (strong, nonatomic) UIPickerView *noiseLevelPickerView;

@property (strong, nonatomic) IBOutlet UITextField *voltageFilterField;
@property (strong, nonatomic) IBOutlet UITextField *rpmFilterField;
@property (strong, nonatomic) IBOutlet UITextField *noiseLevelFilterField;

All the methods for the PickerView are also setup:

// PickerViews //
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 1;
}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    if ([pickerView isEqual: _voltagePickerView]) {
        return voltagePickerValues.count;
    }
    else if () {
        //Rest of PickerView rows
    }
    else {
        return 0;
    }

}

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

    NSString *title;

    if ([pickerView isEqual: _voltagePickerView]) {
        title = [voltagePickerValues objectAtIndex:row];
    }
    else if {
        //Rest of Picker Views
    }

    else {
        title = nil;
    }

    return title;

}

All of this would work fine! I would run the project, TableView would populate, and I could click on the appropriate TextField in order to show the appropriate PickerView with the correct data populated into them.

Then... The only thing I changed (that I can think of) was changing the PlaceHolderText property of one of my UITextFields... that's it, I may have also lined up the TextFields to look better. Then I ran the project and the Pickers would not show when I clicked on a TextField. I checked the Outlets for the TextViews and PickerFields, all the same. I even deleted the Reference Outlets for the TextViews and recreated them. Nothing.

I honestly have no clue what happened. Everything is exactly the same way as it was before with the exception of the PlaceHolderText property of one of the UITextFields .

I've cleaned and rebuilt my project, restarted xcode and even my mac, but nothing.

What am I missing?? Sorry for the lengthy post, and thanks so much if you made it this far.

Answer 1

I ran your code with dummy titles and it worked for me.

One thing that I added that was missing from your code excerpts was:

[self.view addSubview:_voltagePickerView];

where self is the view controller.

Answer 2

Instead of deleting I thought I'd answer in hopes it will help others.

I had to change the hardware settings in the simulator. I don't know why but the simulator seems to be bugged.

Unchecking Hardware => Keyboard => Connect Hardware Keyboard in the simulator fixed the problem.