three dependent picker view - ios

Question

I need to create three independent pickerView's. The first pickerView is categoryPickerView. When a value is selected it should load other 2 pickerView's (productPickerview and modelPickerview) are not loading the data correctly.
The didSelectRow callback is being fired but my NSLog's have shown that its not getting passed the first if statement checking if its equal to "Audio"
For catogeryPickerView I have written following array for it in viewDidLoad:-
devicecatogery=[[NSArray alloc]initWithObjects:#"Audio",#"Video", nil];
//code for numeric keypad done button
UIToolbar* numberToolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 44, 320, 300)];
numberToolbar.barStyle = UIBarStyleBlackTranslucent;
numberToolbar.items = [NSArray arrayWithObjects:
[[UIBarButtonItem alloc]initWithTitle:#"Cancel" style:UIBarButtonItemStyleBordered target:self action:#selector(cancelNumberPad)],
[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil],
[[UIBarButtonItem alloc]initWithTitle:#"Apply" style:UIBarButtonItemStyleDone target:self action:#selector(doneWithNumberPad)],
nil];
[numberToolbar sizeToFit];
// catogery pickerview
categoryPickerView=[[UIPickerView alloc]init];
categoryPickerView.delegate=self;
categoryPickerView.tag=1;
txtCategory.inputView=categoryPickerView;
txtCategory.inputAccessoryView=numberToolbar;
//product pickerview
productPickerView=[[UIPickerView alloc]init];
productPickerView.delegate=self;
productPickerView.tag=2;
txtProduct.inputView=productPickerView;
txtProduct.inputAccessoryView=numberToolbar;
//model pickerview
modelPickerView=[[UIPickerView alloc]init];
modelPickerView.delegate=self;
modelPickerView.tag=3;
txtModel.inputView=modelPickerView;
txtModel.inputAccessoryView=numberToolbar;
}//end of view did load
this is my event for picker view:-
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
if (pickerView.tag == 1) {
return [devicecatogery count]; //<-----------this is for category picker view
}else if(pickerView.tag == 2)
return [commanProductArray count]; //<-----------this is for product picker view
else
return [commanModelArray count]; //<-------------- this is for model picker view
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
if (pickerView.tag == 1)
return [devicecatogery objectAtIndex:row];//<----this is for category picker view
else if (pickerView.tag == 2)
return [commanProductArray objectAtIndex:row];//<--------this is for product picker view
else
return [commanModelArray objectAtIndex:row];//<--------- this is for model picker view
}
Here is my didSelect callback:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
if ([[categoryArray objectAtIndex:[categoryPickerView selectedRowInComponent:0] ] isEqual:#"Audio"]) {
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"walkman",#"mp3",#"ipod", nil];
if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]] isEqual:#"walkman"]) {
// walkman list display
[productPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"walkman1",#"walkman2",#"walkman3",#"walkman4", nil];
[modelPickerView reloadAllComponents];
}else if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]] isEqual:#"mp3"]){
//mp3 list display
[productPickerView reloadAllComponents];
[modelPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"mp3",#"mp3",#"mp3",#"mp3", nil];
}else if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]] isEqual:#"ipod"]){
//ipod list display
[productPickerView reloadAllComponents];
[modelPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"ipod1",#"ipod2",#"ipod3",#"ipod4", nil];
}
}else if ([[categoryArray objectAtIndex:[categoryPickerView selectedRowInComponent:0]] isEqual:#"Video"]){
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"TV",#"Moniter",#"Projector", nil];
if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]]isEqual:#"TV"]) {
//for tv model display
[productPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"TV1",#"TV2",#"TV3", nil];
[modelPickerView reloadAllComponents];
}else if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]]isEqual:#"Moniter"]){
//for moniter model display
[productPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"Moniter1",#"Moniter2",#"Moniter3", nil];
[modelPickerView reloadAllComponents];
}else if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]] isEqual:#"Projector"]){
//for projector display
[productPickerView reloadAllComponents];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"Projector1",#"Projector2",#"Projector3", nil];
[modelPickerView reloadAllComponents];
}
}
}

Answer 1

This code doesn't make sense to me, I suspect your issue is here:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
if ([[categoryArray objectAtIndex:[categoryPickerView selectedRowInComponent:0] ] isEqual:#"Audio"]) {
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"walkman",#"mp3",#"ipod", nil];
if ([[commanProductArray objectAtIndex:[productPickerView selectedRowInComponent:0]] isEqual:#"walkman"]) {
// walkman list display
[productPickerView reloadAllComponents];
All of the pickerView's are going into this callback when selected. You are first of all not checking the tags to see which pickerView it was that fired, then you check if the row selected is audio / video, if its the second / third pickers, the code will never get passed this as they will not have audio / video selected.
Following the logic, if "Audio" is selected you set commanProductArray to the given values, then you immediately check the selected value is equal to "walkman" before loading it.
[productPickerView reloadAllComponents]; should be called directly after commanProductArray is set I suspect, as you set the array and check which value is selected before loading it.
This issue could have been spotted by simply putting 2 or 3 NSlog's to see was it getting into the loop
EDIT:
Your code should follow something more like this:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
// If first picker
if(pickerView.tag == 1)
{
// If Audio
if(row == 0)
{
// Load result for audio
}
// If Video
else if (row == 1)
{
// load result for video
}
}
// If second picker
else if(pickerView.tag == 2)
{
// if Walkman
if(row == 0)
{
// load result for walkman
}
// etc etc etc
}
else if (pickerView.tag == 3)
{
}
}

Answer 2

Try this one:
- (void)viewDidLoad
{
devicecatogery=[[NSArray alloc]initWithObjects:#"Audio",#"Video", nil];
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"walkman",#"mp3",#"ipod", nil];
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"walkman1",#"walkman2",#"walkman3",#"walkman4", nil];
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
}
// tell the picker how many rows are available for a given component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
if (pickerView.tag==1) {
return devicecatogery.count;
}
else if(pickerView.tag==2){
return commanProductArray.count;
}
else if (pickerView.tag==3)
{
return commanModelArray.count;
}
return 0;
}
// tell the picker how many components it will have
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return 1;
}
// tell the picker the title for a given component
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
NSString *title;
if (pickerView.tag==1)
{
title = [NSString stringWithFormat:#"%#",[devicecatogery objectAtIndex:row]];
}
else if (pickerView.tag==2)
{
if([categoryPickerView selectedRowInComponent:0]==0)
{
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"walkman",#"mp3",#"ipod", nil];
}
else{
commanProductArray=[[NSMutableArray alloc]initWithObjects:#"TV",#"Moniter",#"Projector", nil];
}
title = [NSString stringWithFormat:#"%#",[commanProductArray objectAtIndex:row]];
}
else if (pickerView.tag==3)
{
if ([[devicecatogery objectAtIndex:[categoryPickerView selectedRowInComponent:0]] isEqualToString:#"Audio"]) {
if([productPickerview selectedRowInComponent:0]==0)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"walkman1",#"walkman2",#"walkman3",#"walkman4", nil];
}
else if([productPickerview selectedRowInComponent:0]==1)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"mp31",#"mp32",#"mp33",#"mp34", nil];
}
else if([productPickerview selectedRowInComponent:0]==2)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"ipod1",#"ipod2",#"ipod3",#"ipod4", nil];
}
}
else
{
if([productPickerview selectedRowInComponent:0]==0)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"TV1",#"TV2",#"TV3",#"TV4", nil];
}
else if([productPickerview selectedRowInComponent:0]==1)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"Moniter1",#"Moniter2",#"Moniter3",#"Moniter4", nil];
}
else if([productPickerview selectedRowInComponent:0]==2)
{
commanModelArray=[[NSMutableArray alloc]initWithObjects:#"Projector1",#"Projector2",#"Projector3",#"Projector4", nil];
}
}
title = [NSString stringWithFormat:#"%#",[commanModelArray objectAtIndex:row]];
}
return title;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
if (pickerView.tag==1)
{
[productPickerview reloadAllComponents];
[modelPickerview reloadAllComponents];
}
if (pickerView.tag==2) {
[modelPickerview reloadAllComponents];
}
// Handle the selection
}
For more detail you have to check it : Sample code
May it will help you.
Happy coding...:)