java - Android 在 Activity 中显示对话框

Question

我创建了一个扩展 DialogFragment 类的新类:

public class SaveDataDialog extends DialogFragment {
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        // Get the layout inflater
        LayoutInflater inflater = getActivity().getLayoutInflater();

        // Inflate and set the layout for the dialog
        // Pass null as the parent view because its going in the dialog layout
        builder.setView(inflater.inflate(R.layout.save_data_dialog, null))
        // Add action buttons
                .setPositiveButton(R.string.save_data, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                        Toast.makeText(getActivity(), "Testing positive button", Toast.LENGTH_LONG).show();
                    }
                }).setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        SaveDataDialog.this.getDialog().cancel();
                    }
                });
        return builder.create();
    }

}

在我的主要 Activity 中的某个地方(在 onClick 按钮内)，我想显示此对话框。所以我尝试了:

SaveDataDialog sdd = new SaveDataDialog();
sdd.getDialog().show();

第二行给出了空指针异常。

如何显示对话框？这就是我想做的。

Answer 1

您的SaveDataDialog扩展了DialogFragment，您可以调用sdd.show()来显示DialogFragment。