how to hide/show pickerview by click on textfield
<pre><code>    -(void)textFieldDidBeginEditing:(UITextField *)myTextField{  
    [myTextField resignFirstResponder];  
    UITextField *tempbtn;
    tempbtn = myTextField;
    btntagvalue = tempbtn.tag;
    if(btntagvalue == 1)
    {
        if ((quantitypicker.hidden == NO) || (frequencyvalues.hidden == NO) ||(daysnum.hidden ==  
    NO)) {
            [quantitypicker setHidden:YES];
            [frequencyvalues setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((quantitypicker.hidden == NO)||(frequencyvalues.hidden==NO)||(daysnum.hidden==YES)) 
      {
            [quantitypicker setHidden:YES];
            [frequencyvalues setHidden:YES];
        }   
        if ((quantitypicker.hidden==YES)||(frequencyvalues.hidden==NO)||(daysnum.hidden==NO))
     {
            [frequencyvalues setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((quantitypicker.hidden==NO)||(frequencyvalues.hidden==YES)||(daysnum.hidden==NO))
      {
            [quantitypicker setHidden:YES];
            [daysnum setHidden:YES];
        }
        datevalues = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, 150, 320, 280)];
        datevalues.datePickerMode = UIDatePickerModeDateAndTime;
        datevalues.minimumDate=[NSDate date];
        [self.view addSubview:datevalues];
        [datevalues addTarget:self 
       action:@selector(datepicker:)forControlEvents:UIControlEventValueChanged];

        [datevalues release];
    }

    if (btntagvalue == 2) {
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == NO) ||(daysnum.hidden == NO)) {
            [datevalues setHidden:YES];
            [frequencyvalues setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == NO) ||(daysnum.hidden == YES)) {
            [datevalues setHidden:YES];
            [frequencyvalues setHidden:YES];
        }   
        if ((datevalues.hidden == YES) || (frequencyvalues.hidden == NO) ||(daysnum.hidden == NO)) {
            [frequencyvalues setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == YES) ||(daysnum.hidden == NO)) {
            [datevalues setHidden:YES];
            [daysnum setHidden:YES];
        }

        quantitypicker = [[UIPickerView alloc] initWithFrame:CGRectMake(0,190,320,220)];

        if ([meditype isEqualToString:@"Capsules"]) {
            quantitytype = [[NSMutableArray 
        alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",nil];
        }

        if ([meditype isEqualToString:@"Eyedrops"]||[meditype isEqualToString:@"Eardrops"]||\

        [meditype isEqualToString:@"Nosedrops"]) {
            quantitytype = [[NSMutableArray 
        alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",nil];
        }

        if ([meditype isEqualToString:@"Inhaler"]) {
            quantitytype = [[NSMutableArray alloc]initWithObjects:@"1 dose",@"2 doses",@"3 
        doses",@"4 doses",@"5 doses",@"6 doses",@"7 doses",@"8 doses",@"9 doses",@"10 doses",nil];
        }

        if ([meditype isEqualToString:@"Syrup"]) {
            quantitytype = [[NSMutableArray alloc]initWithObjects:@"1 tablespoon",@"2 
            tablespoon",@"3 tablespoon",@"4 tablespoon",@"5 tablespoon",@"6 tablespoon",@"7 
         tablespoon",@"8 tablespoon",@"9 tablespoon",@"10 tablespoon",nil];
        }

        if ([meditype isEqualToString:@"Oils"]) {
            quantitytype = [[NSMutableArray alloc]initWithObjects:@"1 ml",@"2 ml",@"3 ml",@"4 
       ml",@"5 ml",@"6 ml",@"7 ml",@"8 ml",@"9 ml",@"10 ml",nil];
        }
        if ([meditype isEqualToString:@"Injections"]) {
            quantitytype = [[NSMutableArray 
       alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",nil];
        }
        quantitypicker.delegate = self;
        quantitypicker.showsSelectionIndicator = YES;
        quantitypicker.autoresizingMask = UIViewAutoresizingFlexibleWidth;

        [self.view addSubview:quantitypicker];
        }

    if (btntagvalue ==3) {
        if ((datevalues.hidden == NO) || (quantitypicker.hidden == NO) ||(daysnum.hidden == NO)) {
            [datevalues setHidden:YES];
            [quantitypicker setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (quantitypicker.hidden == NO) ||(daysnum.hidden == YES)) {
            [datevalues setHidden:YES];
            [quantitypicker setHidden:YES];
        }   
        if ((datevalues.hidden == YES) || (quantitypicker.hidden == NO) ||(daysnum.hidden == NO)) {
            [quantitypicker setHidden:YES];
            [daysnum setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (quantitypicker.hidden == YES) ||(daysnum.hidden == NO)) {
            [datevalues setHidden:YES];
            [daysnum setHidden:YES];
        }
        frequencyvalues = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 190, 320, 220)];
        arrayfreq = [[NSMutableArray alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",
                     @"6",@"7",@"8",@"9",@"10",@"11",@"12",@"13",@"14",@"15",@"16",
                     @"17",@"18",@"19",@"20",@"21",@"22",@"23",@"24", nil];
        frequencyvalues.delegate = self;
        frequencyvalues.showsSelectionIndicator = YES;
        frequencyvalues.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        [self.view addSubview:frequencyvalues];
    }

    if (btntagvalue ==4) {
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == NO) ||(quantitypicker.hidden == 
      NO)) {
            [datevalues setHidden:YES];
            [frequencyvalues setHidden:YES];
            [quantitypicker setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == NO) ||(quantitypicker.hidden == 
       YES)) {
            [datevalues setHidden:YES];
            [frequencyvalues setHidden:YES];
        }   
        if ((datevalues.hidden == YES) || (frequencyvalues.hidden == NO) ||(quantitypicker.hidden == 
      NO)) {
            [frequencyvalues setHidden:YES];
            [quantitypicker setHidden:YES];
        }
        if ((datevalues.hidden == NO) || (frequencyvalues.hidden == YES) ||(quantitypicker.hidden == 
      NO)) {
            [datevalues setHidden:YES];
            [quantitypicker setHidden:YES];
        }   
        daysnum = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 190, 320, 220)];
        arraytime = [[NSMutableArray alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",
                     @"6",@"7",@"8",@"9",@"10",@"11",@"12",@"13",@"14",@"15",@"16",

         @"17",@"18",@"19",@"20",@"21",@"22",@"23",@"24",@"25",@"26",@"27",@"28",@"29",@"30",@"31", 
         nil];
        daysnum.delegate = self;
        daysnum.showsSelectionIndicator = YES;
        daysnum.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        [self.view addSubview:daysnum];
    }
}
</code></pre>
