这是我的Dialog类代码，我在我的片段中实现了这个ApplyDialog监听器。我已经在我的片段中实现了这个ApplyDialog监听器，我在onAttach方法中得到了错误。每当我打开这个对话框时，应用程序就会崩溃。我想把对话框中的一些文本保存到我的片段中。我已经从这个类中删除了一些代码来发布这个问题。
public class DiscountDialog extends AppCompatDialogFragment {
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View view = inflater.inflate(R.layout.discount_dialog,null);
builder.setView(view)
.setTitle("Discount")
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
})
.setPositiveButton("Add", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String DiscountName = select_discount_category.toString();
String DiscountAmount = discount_amount.getText().toString();
String DiscountType = discountType.toString();
listner.applyDialog(DiscountName,DiscountAmount,DiscountType);
}
});
new_discount_name = (EditText) view.findViewById(R.id.new_discount_name);
discount_amount = (EditText) view.findViewById(R.id.discount_amount);
select_discount_category = (Spinner) view.findViewById(R.id.select_discount_category);
select_discount_type = (Spinner) view.findViewById(R.id.select_discount_type);
add_discount_category = (ImageButton) view.findViewById(R.id.add_discount_category);
stringlist = new ArrayList<>(Arrays.asList(discountItems));
typeList = new ArrayList<>(Arrays.asList(discountType));
arrayadapter = new ArrayAdapter<String>(getActivity(),R.layout.discount_dialog_text,stringlist);
arrayadapter.setDropDownViewResource(R.layout.discount_dialog_text);
select_discount_category.setAdapter(arrayadapter);
typeAdapter = new ArrayAdapter<String>(getActivity(),R.layout.discount_dialog_text,typeList);
typeAdapter.setDropDownViewResource(R.layout.discount_dialog_text);
select_discount_type.setAdapter(typeAdapter);
add_discount_category.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
GETTEXT = new_discount_name.getText().toString();
stringlist.add(GETTEXT);
arrayadapter.notifyDataSetChanged();
Toast.makeText(getActivity(), "Item Added", Toast.LENGTH_LONG).show();
}
});
return builder.create();
}
我在这个方法中得到这个错误
@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
listner = (discountDialogListner) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString() + "Must Implement discountDialogListner"); //This is the line where I'm getting this error
}
}
public interface discountDialogListner
{
void applyDialog(String DiscountName,String DiscountType,String DiscountAmount);
}
}
这是因为上下文的类型不属于 "我的"。discountDialogListner.
为了启动你的监听器，你的活动需要做到 implement 你的 interface discountDialogListner.
希望这能解决你的问题。
我已经自己解决了，非常感谢你，我想在片段中实现这个功能，但我必须在MainActivity中实现对话框。