Question

In my application i created a button when the button is clicked it will load all images from the sdcard.

Answer 1

You just pass the path of image to another activity and then get image from that particular path in another activty. You can start activity inside of onItemClickListener.
Just try this code.

sdcardImages.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView parent, View v, int position, long id) {
        // Get the data location of the image
        String[] projection = {MediaStore.Images.Media.DATA};
        cursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                projection, // Which columns to return
                null,       // Return all rows
                null,
                null);
        columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToPosition(position);
        // Get image filename
        String imagePath = cursor.getString(columnIndex);

         Intent i = new Intent(Images.this, GreetingCard.class);
           i.putExtras("path",imagePath);
                    startActivity(i);
                    finish();   
    }
});