Android Fill Data Array Dynamic

Question

I'm stucked with filling an Array dynamic.

I can't find the solution. Normal I would fill the array just by any loop.

It's not working in this case I really spent hours to find a solution.

I found an example to use a custom list in android. works fine.

I create a object Test.

public class Test {
public int icon;
public int PB;
public String title;
public Test(){
    super();
}

public Test(int icon, String title, int PB) {
    super();
    this.icon = icon;
    this.title = title;
    this.PB = PB;
}

}

and fill it static here works fine. But I don't get how to fill it dynamic.

Test test_data[] = new Test[]
    {
        new Test(R.drawable.ic_launcher, "Test 1", 10),
        new Test(R.drawable.ic_launcher, "Test 2", 100)
    };

I'm getting data from a database and want to fill this object with the data everytime the activity starts. — bnz
– bnz, Commented May 21, 2012 at 6:50

thepoosh · Accepted Answer · 2012-05-21 07:12:35Z

1

dynamic assigning of data to an array as is follows:

 Test [] test_data = 
{
    new Test(R.drawable.ic_launcher, "Test 1", 10),
    new Test(R.drawable.ic_launcher, "Test 2", 100)
};

EDIT:

this can be done only in the first time you instance the array. if you already know how big the array is gonna be you should do this:

Test [] test_array = new Test[size];
for (int i=0; i<size; i++) {
    //DO STUFF
}

if you don;t know the size from the start what you should do is use a ListArray and then convert it to a simple array (or not), here is the code for that:

ListArray<Test> list = new ListArray<Test>();
// INSERT VALUES

public Test[] listToArray(ArrayList<Test> list) {
     Test [] result = new Test [list.size());
     for (int i = 0; i<list.size(); i++) {
        result[i] = list.get(i);
     }
     return result;
}

edited May 21, 2012 at 7:12

answered May 21, 2012 at 6:57

thepoosh

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2 Comments

bnz Over a year ago

Thanks alot! I knew theres a simple sultion i didn't get because my mind was stuck!

bnz Over a year ago

But well wait I have been too fast. Can you give me an example filling this by a loop? I'm really stucked :(

bnz · Accepted Answer · 2012-05-21 12:24:55Z

1

You can use ArrayList instead of static array.

    In case of array u have to define the size at compile time and then add objects to it like:

    Test test_data[] = new Test[10];
    test_data[0] = new Test(R.drawable.ic_launcher, "Test 1", 10);
    test_data[1] = new Test(R.drawable.ic_launcher, "Test 2", 100);
    ....................

I tried the code above. This is what giving me the NULL Pointer Exception.

I'm getting data from a database and want to fill this object with the data everytime the activity starts


 You have to use ArrayList like:

 ArrayList<Test> test_data = new ArrayList<Test>;

 test_data.add(new Test(R.drawable.ic_launcher, "Test 1", 10));
 test_data.add(new Test(R.drawable.ic_launcher, "Test 2", 100));

..........
And clear ArrayList by test_data.clear()

edited May 21, 2012 at 12:24

bnz

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answered May 21, 2012 at 6:48

Himanshu Mohta

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4 Comments

bnz Over a year ago

I tried the first Code Example he gave me. If I use an ArrayList I have to restructe the whole code.

bnz Over a year ago

I took the first code example and i got an the exception. If I change to an ArrayList i have to change a lot. So I'm looking for a way to avoid this.

bnz Over a year ago

Tried it over and over now its working due any magic reason! Thanks alot.

thepoosh Over a year ago

@HimanshuMohta, you have some errors in your code. since it has already been edited, I can't fix them, but you should notice that ArrayList should call a constructor (new ArrayList<Test>())

Barak · Accepted Answer · 2012-05-21 06:59:21Z

0

You need to initialize the array. Since you are using a database, the data must be coming from a cursor, so you can do this:

Test test_data[] = new Test[cursor.getCount()]

That will create a slot for each record in your cursor. Then you can run through your loop and populate it.

answered May 21, 2012 at 6:59

Barak

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1 Comment

bnz Over a year ago

The Size isnt the Problem. I tried this static It's giving me a NULL Pointer Exception.

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