Question

我正在制作一个列表视图，当你点击一个项目时，它会显示一个带有2个选项的alertdialog，在他们选择一个选项后，它会将它们带回列表视图，在那里他们可以再次使用其他选项。出于某种原因，一旦我点击一个项目，如果我点击肯定按钮（其中包含代码的那个），然后尝试点击另一个项目，警报对话框不会弹出。有谁知道为什么会这样？代码如下：

protected void onListItemClick(ListView l, View v, int position, long id) {
        final int i = position;
        try {
            new AlertDialog.Builder(this)
            .setTitle("Download")
            .setMessage("You have selected the level " + jArray.getJSONObject(i).getString("level_name") + ". Would you like to save it?")
            .setPositiveButton("Save", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which) {
                    try {
                        saveLevel(jArray.getJSONObject(i).getString("level_name"),jArray.getJSONObject(i).getInt("id"));
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    return;
                } 
            })
            .setNegativeButton("Cancel",new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which) {
                    return;
                } 
            })
            .show();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        super.onListItemClick(l, v, position, id);
    }

如果您需要任何其他信息，请告诉我们！提前谢谢！

威廉

修改的

据我所知，它发生在saveLevel函数中，我将它发布在

之下

public void saveLevel(String i, int id)
{
    InputStream is = null;
    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("uid","demo"));
    String result = "";
    try
    {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("www.example.com/stuff.php");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        is = entity.getContent();

        BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();

        result=sb.toString();
        jArray = new JSONArray(result);
        File exst = Environment.getExternalStorageDirectory();
        String exstPath = exst.getPath();

        File filePath = new File(exstPath+"/Platformer/Downloaded");
        boolean success = filePath.mkdir();
        String path = filePath.getAbsolutePath() + "/" + i + ".xml";
        File newxmlfile = new File(path);
        try 
        {
            newxmlfile.createNewFile();
        } 
        catch (IOException e) 
        {
            e.printStackTrace();

        }
        FileOutputStream fileos = null;        
        try
        {
            fileos = new FileOutputStream(newxmlfile);
        }
        catch(FileNotFoundException e)
        {
            Log.e("FileNotFoundException", "can't create FileOutputStream");
            return;
        }
        OutputStreamWriter output = new OutputStreamWriter(fileos);
        output.write(jArray.getJSONObject(0).getString("level_data"));
        output.flush();
        output.close();
    }
    catch(Exception e)
    {
        Log.e("log_tag", "Error parsing data "+e.toString());
    }
}

Answer 1

您的saveLevel()函数执行了许多不适合UI线程的事情（网络访问，文件访问）。您应该将这些内容分成后台主题，最好使用AsyncTask（tutorial）。

当您尝试点击其他列表项时，很可能您的程序仍然卡在saveLevel()中。如果你想检查这个假设是否真的如此，只需在return;的开头放一条saveLevel()行，看看你的对话框是否按预期弹出。

OnListItemClick只工作一次

1 个答案: