所以我有一个自定义的列表视图。它就像Instagram布局,每个列表项中都有1张图片和一堆按钮。这里是问题:
我想实现分享按钮。为此,我尝试从适配器到活动创建回调。但似乎并没有起作用。这是我目前的代码(我裁剪了不相关的部分):
MainActivity
public class MainActivity extends ActionBarActivity implements ListAdapter.OnShareClickedListener{
ListView main_list;
List<String> url_list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
main_list = (ListView) findViewById(R.id.listView);
ListAdapter nListAdapter = new ListAdapter(context, url_list);
main_list.setAdapter(nListAdapter);
}
@Override
public void ShareClicked(String url) {
Log.e("Test",url);
}
}
public class ListAdapter extends BaseAdapter implements View.OnClickListener {
OnShareClickedListener mCallback;
Context context;
public static List<String> url_list;
public ListAdapter(Context c, List<String> list) {
this.context = c;
url_list = list;
}
public interface OnShareClickedListener {
public void ShareClicked(String url);
}
@Override
public void onClick(View v) {
mCallback.ShareClicked("Share this text.");
}
}
}
错误日志:
Attempt to invoke interface method 'void com.packagename.ListAdapter$OnShareClickedListener.ShareClicked(java.lang.String)' on a null object reference
codota
网站。如果是,有哪些本地替代方案。可能需要参考链接。 - r.sumesh