How can I present a picker view just like the keyboard does?

问题

I want a UIPickerView to show up when I press a button (just like keyboard) and then go away when user taps anywhere on the screen. How can I do this? Thanks.

A bit more background: I have a UITextField called months in UITableViewCell. Now the best option for me is to put a UIPikcerView there and it will be easier for the user to just chose the month rather than having to type it out (and it's the better way). But UIPickerView looks really ugly in a UITableViewCell, not to mention I can't change it's gigantic size. So what should I do in this case?

回答1:

This is how you should use UIPickerView for a textField in a UITableView.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
    cell.selectionStyle= UITableViewCellSelectionStyleNone;
    UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(110, 10, 185, 30)];
    textField.clearsOnBeginEditing = NO;
    textField.textAlignment = UITextAlignmentRight;
    textField.delegate = self;
    [cell.contentView addSubview:textField];
    //textField.returnKeyType = UIReturnKeyDone;
    cell.textLabel.backgroundColor = [UIColor clearColor];
    cell.detailTextLabel.backgroundColor = [UIColor clearColor];

        // if you want a UIPickerView for first row... then do the following //
        // Here.. packSizePickerView is an object of UIPickerView

   if (indexPath.row == 1)
  {
    textField.tag=0;
    textField.delegate= self;
    packSizePickerView.delegate = self;
    packSizePickerView = [[UIPickerView alloc] init];
    packSizePickerView.autoresizingMask=UIViewAutoresizingFlexibleWidth;
    packSizePickerView.showsSelectionIndicator=YES;
    textField.inputView  = packSizePickerView;
    }

    // if you want to select date / months  in row 2, go for UIDatePickerView //

    if (indexPath.row == 1)
    {
        textField.tag = 1;
        UIDatePicker *datePicker = [[UIDatePicker alloc] init];
        datePicker.datePickerMode = UIDatePickerModeDate;
       [datePicker addTarget:self action:@selector(datePickerValueChangedd:) forControlEvents:UIControlEventValueChanged];
        datePicker.tag = indexPath.row;
        textField.delegate= self;
        textField.inputView = datePicker;
        [datePicker release];

    }

}

// Configure the cell...

NSInteger row = [indexPath row];
cell.textLabel.text = [myArray objectAtIndex:row];

return cell;

}

And for datePickerValueChangedd

- (void)datePickerValueChangedd:(UIDatePicker*) datePicker{
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 50, 68, 68)];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
df.dateStyle = NSDateFormatterMediumStyle;
label.text = [NSString stringWithFormat:@"%@",[df stringFromDate:datePicker.date]];

    NSLog(@"I am inside the datePickerValueChanged   - - %@", label.text);
[df release];
    globalValue1 = label.text;

   // use a global variable to copy the value from the pickerView. //
   }

Now in the textFieldDidEndEditing:

-(void) textFieldDidEndEditing:(UITextField *)textField {
if (textField.tag ==0)
   [textField setText: globalValue0];

if (textField.tag ==1)
   [textField setText: globalValue1];

}

And to resign UIDatePicker, set the UIView as a UIControl and

resignFirstResponder

回答2:

I think that you need to put your UIPickerView "outside" the viewable screen and animate it in when the button is pressed. I'm not really sure what the best way to get rid of it would be but you could probably listen for a tap on the parent view when the picker is visible and then animate it back out.

来源：https://stackoverflow.com/questions/6269244/how-can-i-present-a-picker-view-just-like-the-keyboard-does

标签

objective-c

cocoa-touch

ios

uipickerview