Android - Java相当于iOS的Block回调

Question

在我的Android应用程序中，我想实现成功和错误回调，当我从我的后端获得阅读段落。在iOS中，它看起来像这样:

In my Passage.h:

-(void)getPassagesWithSuccessCallback:(void (^)(NSArray<Passage *> *))success errorCallback:(void (^)(NSString *))errorString;

In my Passage.m:

-(void)getPassagesWithSuccessCallback:(void (^)(NSArray<Passage *> *))success errorCallback:(void (^)(NSString *))errorString {
    MyApiInterface* api = [MyApiInterface sharedInstance];
    [api sendGetRequestTo:@"passages" successCallback:[Passage modelListCallback:success] errorCallback:error];
}

在我的Android应用程序中，我使用Volley来处理我的API请求，但我想通过使用一个具有public static void方法的Passage.java类来进一步封装这个API接口。像这样:

public static void getPassagesForFirebaseUser(FirebaseUser user, Context context) {
        final String url = URL_BASE + "/passages.json" + "?auth=" + user.getToken(false);
        final JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                // convert JSON into ArrayList<Passage> object
                // pass on this array of Passages in the success completion listener of the method that called this
                // just like iOS does success(passages)
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                // convert error to string
                // pass on this errorString in the error completion listener of the method that called this
                // just like iOS does error(errorString)
            }
        });
        Volley.newRequestQueue(context).add(request);
}

是否有办法获得这种实现流程?

Answer 1

你可以使用一个接口

public interface ICallbacks { 
    public void onResponse(JSONObject response);
    public void onError(VolleyError error);
}

然后在你的例程代码中放入一个新的回调实例(取决于你工作的ide可以自动生成方法)

public static void getPassagesForFirebaseUser(FirebaseUser user,
Context context, ICallbacks events) { 
//here code and call ICallbacks methods
if(result){ events.onResponse(response); }
if(error){ events.onError(err); }
}

最终你可以用:

getPassagesForFirebaseUser(user, context, new ICallbacks(){
    @Override
    public void onResponse(JSONObject response){
        //Success !!!
    }
    @Override
    public void onError(VolleyError response){
        //Error !!!
    }
});

很抱歉我的英语不好，希望这对你有帮助!