使图像在android中掉落

Question

I am making an android game which needs to display some different images. I need to make a method that keeps on generating images from a resource in the drawable directory and then drop the images from the top of the screen to the bottom. I also need that each image should have an id "image-1" "image-2" in which the index number goes higher once more images are created as an integer. I also need them to be generated at different locations at the top of the screen and drop with a specified speed. Once they hit the bottom, I want a method to be executed like:

public void touchedGround() {
//My code
}

I am using this code so far:

import android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;

public class GameScreenActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gamescreen);
    generateParachuters(savedInstanceState);
}

private void generateParachuters(Bundle icicle) {
    // TODO Auto-generated method stub
    Toast.makeText(getApplicationContext(), "generating images", 10).show();
}
}

Answer 1

I know one way to do it, but it requires a lot more code then what you're probably looking for. But hey, here goes.

1. Create a class for your falling object, which I'm guessing is a Parachuter . This class will have an X and Y variable to keep track of where it is on the screen. You can then have a tick method, which will increase the Y variable by however fast you want it to fall. You can also have them keep track of a integer ID if you want.

2. Create a list that will hold the Parachuter objects. I use an ArrayList. This way you create a Parachuter when needed and add it to the list. Cycle through the list to draw each one.

3. You need something to draw the Parachuter s with. Personally, I use Canvas from SurfaceView .

4. You'll need a looping animation. Loop through, each time drawing the Parachuter s and calling tick on each one.

5. During the loop, you can check the position of each Parachuter . If its position goes beyond Canvas.getHeight() , remove the image from the list.

Well, that's quite a bit there. Ask me if you need further clarification.

UPDATE : Here's a fully-working example .

UPDATE 2 :

//Check right edge of screen
for (int i = 0; i < parachuters.size(); i++)
{
    if (parachuters.get(i).getX() > canvas.getWidth())
        //Do whatever it is you want
}