如何在StaggeredGridView中使用OnItemClickListener？

Question

我从这里下载了StaggeredGridView库和demo： https://github.com/maurycyw/StaggeredGridViewDemo https://github.com/maurycyw/StaggeredGridView

它在StaggeredGridView库中实现了OnItemClickLister。我一直在尝试使用它，但我不断让我的应用程序崩溃。这是我的代码。

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Toast;
import com.origamilabs.library.views.StaggeredGridView;
import com.origamilabs.library.views.StaggeredGridView.OnItemClickListener;

public class MainActivity extends Activity implements OnItemClickListener {

StaggeredAdapter adapter;

public String urls[] = {

"http://farm9.staticflickr.com/8462/8005636463_0cb4ea6be2.jpg",
        "http://farm8.staticflickr.com/7232/6913504132_a0fce67a0e_c.jpg",
        "http://farm5.staticflickr.com/4133/5096108108_df62764fcc_b.jpg",
        "http://farm5.staticflickr.com/4074/4789681330_2e30dfcacb_b.jpg",
        "http://farm9.staticflickr.com/8208/8219397252_a04e2184b2.jpg",
        "http://farm9.staticflickr.com/8483/8218023445_02037c8fda.jpg",
        "http://farm9.staticflickr.com/8335/8144074340_38a4c622ab.jpg",
        "http://farm9.staticflickr.com/8060/8173387478_a117990661.jpg",
        "http://farm9.staticflickr.com/8056/8144042175_28c3564cd3.jpg",
        "http://farm9.staticflickr.com/8183/8088373701_c9281fc202.jpg",
        "http://farm9.staticflickr.com/8185/8081514424_270630b7a5.jpg",
        "http://farm9.staticflickr.com/8462/8005636463_0cb4ea6be2.jpg",
        "http://farm9.staticflickr.com/8306/7987149886_6535bf7055.jpg",
        "http://farm9.staticflickr.com/8444/7947923460_18ffdce3a5.jpg",
        "http://farm9.staticflickr.com/8182/7941954368_3c88ba4a28.jpg",
        "http://farm9.staticflickr.com/8304/7832284992_244762c43d.jpg",
        "http://farm9.staticflickr.com/8163/7709112696_3c7149a90a.jpg",
        "http://farm8.staticflickr.com/7127/7675112872_e92b1dbe35.jpg",
        "http://farm8.staticflickr.com/7111/7429651528_a23ebb0b8c.jpg",
        "http://farm9.staticflickr.com/8288/7525381378_aa2917fa0e.jpg",
        "http://farm6.staticflickr.com/5336/7384863678_5ef87814fe.jpg",
        "http://farm8.staticflickr.com/7102/7179457127_36e1cbaab7.jpg",
        "http://farm8.staticflickr.com/7086/7238812536_1334d78c05.jpg",
        "http://farm8.staticflickr.com/7243/7193236466_33a37765a4.jpg",
        "http://farm8.staticflickr.com/7251/7059629417_e0e96a4c46.jpg",
        "http://farm8.staticflickr.com/7084/6885444694_6272874cfc.jpg" };

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    StaggeredGridView gridView = (StaggeredGridView) this
            .findViewById(R.id.staggeredGridView1);

    int margin = getResources().getDimensionPixelSize(R.dimen.margin);
    gridView.setItemMargin(margin);
    gridView.setPadding(margin, 0, margin, 0);
    StaggeredAdapter adapter = new StaggeredAdapter(MainActivity.this,
            R.id.imageView1, urls);
    gridView.setAdapter(adapter);
    adapter.notifyDataSetChanged();

    gridView.setOnItemClickListener(this);


}

这是onItemClick方法：

@Override
public void onItemClick(StaggeredGridView parent, View view, int position,
        long id) {

    String item = adapter.getItem(position).toString();
    Toast.makeText(MainActivity.this, "You have chose: "+ item, Toast.LENGTH_LONG).show();

}