java - Android，我如何在 Controller 中使用 hellper 方法的回调？

Question

我在 Controller 中调用了以下 Helper 方法:

DialogHelper.showListDialog(R.string.select_recipient_please, recipientsArr, null, context);

和辅助方法:

public static void showListDialog(int title, String[] items, Drawable icon, Context ctx) {
        new MaterialDialog.Builder(ctx)
                .title(title)
                .items(items)
                .itemsCallbackSingleChoice(-1, new MaterialDialog.ListCallbackSingleChoice() {
                    @Override
                    public boolean onSelection(MaterialDialog dialog, View view, int which, CharSequence text) {
                        Logger.d("Selected");
                        Logger.d(String.valueOf(which));
                        /**
                         * If you use alwaysCallSingleChoiceCallback(), which is discussed below,
                         * returning false here won't allow the newly selected radio button to actually be selected.
                         **/
                        return true;
                    }
                })
                .positiveText("Select")
                .show();
    }

我想在 Controller 而不是助手中处理重写的 onSelection 方法。

请问我该如何以正确的方式做到这一点？我应该为此使用接口(interface)吗？

非常感谢您的任何建议或示例。

编辑:添加了对我不起作用的示例

Controller 方法:

public void showRecipientsPicker(ArrayList<String> recipents){
        try {
            String[] recipientsArr = new String[recipents.size()];
            recipientsArr = recipents.toArray(recipientsArr);
            DialogHelper dh = new DialogHelper(context);

            dh.showListDialog(R.string.select_recipient_please, recipientsArr, null, new DialogHelperListener() {
                @Override
                public void onSelection(MaterialDialog dialog, View view, int which, CharSequence text) {
                    Logger.d("TEST");
                    Logger.d(String.valueOf(which));
                }
            });


        } catch (Exception e){
            Logger.d(e.getMessage());
            toastHelper.showToast(R.string.cannot_show_recipients,
                    Constants.Global.TOAST_DURATION_MEDIUM);
            TrackingEventLogHelper.logException(e, Constants.Global.EXCEPTION,
                    Constants.ExceptionMessage.EXC_CANNOT_SHOW_RECIPIENT_LIST, true);

        }
    }

接口(interface)类:

public interface DialogHelperListener  {
    void onSelection(MaterialDialog dialog, View view, int which, CharSequence text);
}

帮助类:

public class DialogHelper {

    private Context mCtx;

    public DialogHelper(Context ctx) {
        mCtx = ctx;
    }


    /**
     * Creating a list dialog only requires passing in an array of strings
     */
    public void showListDialog(int title, String[] items, Drawable icon, DialogHelperListener callback) {
        new MaterialDialog.Builder(this.mCtx)
                .title(title)
                .items(items)
                .itemsCallbackSingleChoice(-1, (MaterialDialog.ListCallbackSingleChoice) callback)
                .positiveText("Select")
                .show();
    }





}

它抛出以下异常:

controller.MessageController$2 cannot be cast to com.afollestad.materialdialogs.MaterialDialog$ListCallbackSingleChoice

Answer 1

您可以将回调接口(interface)作为参数添加到函数中，如下所示:

public static void showListDialog(int title, String[] items, Drawable icon, Context ctx, MaterialDialog.ListCallbackSingleChoice callback) {
  new MaterialDialog.Builder(ctx)
                .title(title)
                .items(items)
                .itemsCallbackSingleChoice(-1, callback)
                .positiveText("Select")
                .show();
}

然后在您的 Controller 中，您可以实现此行为:

showListDialog(title, items, icon, ctx, new MaterialDialog.ListCallbackSingleChoice(){
  @Override
  public boolean onSelection(MaterialDialog dialog, View view, int which, CharSequence text) {
    //Do something here
  }
})

编辑

这里出现的问题是您的方法接受 DialogHelperListener 并且您尝试将其转换为 MaterialDialog.ListCallbackSingleChoice。现在我假设您想要为 Controller 代码使用 DialogHelperListener 接口(interface)。您不能简单地进行转换，您需要实现 MaterialDialog.ListCallbackSingleChoice 并调用您自己的接口(interface)，如下所示:

public void showListDialog(int title, String[] items, Drawable icon, DialogHelperListener callback) {
        new MaterialDialog.Builder(this.mCtx)
                .title(title)
                .items(items)
                .itemsCallbackSingleChoice(-1, new MaterialDialog.ListCallbackSingleChoice(){
                  @Override
                  public boolean onSelection(MaterialDialog dialog, View view, int which, CharSequence text) {
                    callback.onSelection(dialog, view, which);
                  }
                })
                .positiveText("Select")
                .show();
}

虽然我不确定为什么您想要使用直接模仿 MaterialDialog.ListCallbackSingleChoice 界面的界面