How to copy NSMutableArray value into another NSMutableArray in iPhone? - iphone

Question

Here, i have a NSMutableArray in my AppDelegate page, the array will be updated when the user add the values (user name) in the database. Now i want the array values(user name) to be displayed in the next view to be list out in the Picker View. I know there is more related questions is there, but i can't find the solution. Any help appreciated.
Here is my code:
The array i have declared in the AppDelegate page, named jobarray, now i need to copy the items in the jobarray into next view, there i have declared pickerarray.
pickerarray = [[NSMutableArray alloc] initWithArray:appDelegate.jobarray copyItems:YES];
But it returns error message,
['NSInvalidArgumentException', reason: '-[Coffee copyWithZone:]: unrecognized selector sent to instance 0x822d410'] where 'Coffee' is my sqlite3 object file.

Answer 1

Your SQLite object does not conform to the NSCopying protocol - you haven't implemented the
- (id)copyWithZone:(NSZone *)zone;
method. You can either implement this method to make your object copyable, but if you only need the copying for displaying, you'd better copy the array itself only:
NSMutableArray *newArray = [originalArray mutableCopy];
this only retains the first array's objects, no need to mess with implementing the copying protocol.

Answer 2

[arr1 initWithObjects:#"1",#"2", nil];
makes no sense, what you probably want is to use the NSMutableArray:
NSArray *arr1 = [NSArray arrayWithObjects:#"1",#"2", nil];
NSMutableArray *arr2 = [arr1 mutableCopy];
NSLog(#"arr1: %p, %#", arr1, arr1);
NSLog(#"arr2: %p, %#", arr2, arr2);
NSLog output:
arr1: 0x7924c50, (
1,
2
)
arr2: 0x7924f00, (
1,
2
)

Answer 3

To populate a UIPickerView from an array you need to first create a connection for the UIPickeView Data Source and Delegate back to the ViewController. You can do this by CTRL dragging in Interface Builder in the normal way - from your UIPickerView control.
You will also need to ensure that you include the delegate protocal to your interface file. So something like this;
#ViewController : UIViewController<UIPickerViewDataSource, UIPickerViewDelegate> {
}
Then you will need to create the delegated methods for the population of the UIPickerView in your implementation file.
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
//One column
return 1;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
//set number of rows
return myArrayObject.count;
}
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
//set item per row
return [myArrayObject objectAtIndex:row];
}
This assumes that myArrayObject has been properly declared and populated elsewhere. I.e. in viewDidLoad - if content is static.