Question

我已经实现了Fedor的Lazy Load代码来实现我的应用程序的一个子集。我正在使用facebook sdk提取数据并在活动中显示带有评论的新闻源帖子，如计数等。还有一个评论框，您可以使用该评论框发布评论到新闻源帖子。这个功能很好用。然而，我想要做的是，在用户将评论发布到帖子后，列表应该刷新并显示他刚发布的评论。我在发布评论后立即尝试在onClick方法中调用adapter.notifyDataSetChanged();。列表视图永远不会刷新。

如果我在这里错了，请纠正我，但我最好的猜测是，我用来保存数据的arraylist并不令人耳目一新。以下是代码的相关部分（我认为）。如果需要更多，请告诉我。

onCreate方法：使用JSONObject和JSONArray初始化ArrayLists并提取数据

arrayUserID = new ArrayList<String>();
arrayProfilePic = new ArrayList<String>();
arrayFromName = new ArrayList<String>();
arrayMessage = new ArrayList<String>();


try {

    JOFeedDetails = new JSONObject(apiResponse);
    JAFeedDetails = JOFeedDetails.getJSONArray("data");


    for (int i = 0; i < JAFeedDetails.length(); i++) {
        json_data = JAFeedDetails.getJSONObject(i);

        // GET THE POST'S FROM USER NAME AND ID
        JSONObject joFromName = new JSONObject();
        joFromName = json_data.optJSONObject("from");

        if (joFromName.has("id"))   {
            String getCommentersID = joFromName.getString("id");
            arrayUserID.add(getCommentersID);
            String fromProfilePic = "https://graph.facebook.com/"+ getCommentersID +"/picture?type=square" + "&access_token=" + Utility.mFacebook.getAccessToken();;
            arrayProfilePic.add(fromProfilePic);
        } else {
            String getCommentersID = "";
            arrayUserID.add(getCommentersID);
        }

        if (joFromName.has("name")) {
            String getCommentersName = joFromName.getString("name");
            arrayFromName.add(getCommentersName);
        } else {
            String getCommentersName = "";
            arrayFromName.add(getCommentersName);
        }

        if (json_data.has("message"))   {
            String getMessage = json_data.getString("message");
            arrayMessage.add(getMessage);
        } else {
            String getMessage = "";
            arrayMessage.add(getMessage);
        }

        // GET THE POST'S TIME STAMP
        if(json_data.has("created_time"))   {

            String dateStr = json_data.optString("created_time");
            SimpleDateFormat formatter = getDateFormat();
            ParsePosition pos = new ParsePosition(0);
            long then = formatter.parse(dateStr, pos).getTime();
            long now = new Date().getTime();

            long seconds = (now - then)/1000;
            long minutes = seconds/60;
            long hours = minutes/60;
            long days = hours/24;

            String friendly = null;
            long num = 0;
            if (days > 0) {
                num = days;
                friendly = days + " day";
            } else if (hours > 0) {
                num = hours;
                friendly = hours + " hour";
            } else if (minutes > 0) {
                num = minutes;
                friendly = minutes + " minute";
            } else {
                num = seconds;
                friendly = seconds + " second";
            }
            if (num > 1) {
                friendly += "s";
            }
            String postTimeStamp = friendly.toUpperCase() + " AGO";
            arrayTimeStamp.add(postTimeStamp);
        } else {
            String postTimeStamp = "";
            arrayTimeStamp.add(postTimeStamp);
        }

        if (json_data.has("likes")) {
            String getCommentLikes = json_data.getString("likes");
            arrayCountLikes.add(getCommentLikes);
        } else {
            String getCommentLikes = "0";
            arrayCountLikes.add(getCommentLikes);
        }
    }

} catch (Exception e) {
}

stringUserID = new String[arrayUserID.size()];
stringUserID = arrayUserID.toArray(stringUserID);

stringProfilePics = new String[arrayProfilePic.size()];
stringProfilePics = arrayProfilePic.toArray(stringProfilePics);

stringFromName = new String[arrayFromName.size()];
stringFromName = arrayFromName.toArray(stringFromName);

stringMessage = new String[arrayMessage.size()];
stringMessage = arrayMessage.toArray(stringMessage);

stringTimeStamp = new String[arrayTimeStamp.size()];
stringTimeStamp = arrayTimeStamp.toArray(stringTimeStamp);

stringCountLikes = new String[arrayCountLikes.size()];
stringCountLikes = arrayCountLikes.toArray(stringCountLikes);

getNewsfeedDetailsHeader();

adapter = new NewsFeedDetailsAdapter(this, stringUserID, stringFromName, stringProfilePics, 
        stringMessage, stringTimeStamp, stringCountLikes);

list.setAdapter(adapter);

发布评论的onClick事件：

public OnClickListener listener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            try {
                Bundle parameters = new Bundle();
                parameters.putString("message", txtCommentBox.getText().toString());
                parameters.putString("description", getString(R.string.app_desc));
                parameters.putString("caption", getString(R.string.app_name));

                Utility.mFacebook.request(fetchedThreadID + "/comments", parameters, "POST");

                adapter.notifyDataSetChanged();

                InputMethodManager inputManager = (InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
                inputManager.hideSoftInputFromWindow(txtCommentBox.getWindowToken(), 0);
                txtCommentBox.setText("");
            } catch (Exception e) {
            }
        }
    };

我非常感谢您耐心等待这篇长篇文章。但我真的认为理解流程可能会有所帮助。我希望有人能帮助我解决这个问题。

Answer 1

一旦我的ArrayLists没有更新，我遇到了类似的问题。

尝试在适配器之前调用你的Arraylist上的.clear（）。这对我来说很有用。祝你好运！

刷新使用Lazy Load和JSON实现的ListView

1 个答案: