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我收到此錯誤：構造函數是不確定的ArrayAdapter
The constructor AllProductsActivity.MyAdapter(AllProductsActivity, int, ArrayList<HashMap<String,String>>) is undefined
在這一行：
MyAdapter adapter = new MyAdapter(AllProductsActivity.this, R.layout.list_item, productsList);
我最好的猜測是，產品列表是問題，但經過2天左右的努力瞭解代碼，我還沒弄明白。很多代碼都來自本教程，說實話我不明白什麼是hashmap。 - http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/
我知道它很吸引人，幫助堆棧溢出的人看起來無能爲力，但我真的可以用正確的方向推動。 HashMap類的概述就像對我來說是胡言亂語（http://developer.android.com/reference/java/util/HashMap.html）
在此先感謝您的任何幫助。
這裏是我的整個AllProductsActivity：
public class AllProductsActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_all_products = "http://mywebsite/mycameraapp/android_connect/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_DESCRIPTION = "description";
// products JSONArray
JSONArray products = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// on selecting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
/** CALLED WHEN THE USER CLICKS THE RECORD BUTTON */
public void sendMessage(View view) {
Intent videoIntent = new Intent(this, PhotoIntentActivity.class);
startActivity(videoIntent);
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllProductsActivity.this);
pDialog.setMessage("Loading trends...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
String description = c.getString(TAG_DESCRIPTION);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
map.put(TAG_DESCRIPTION, description);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewProductActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
MyAdapter adapter = new MyAdapter(AllProductsActivity.this, R.layout.list_item, productsList);
// updating listview
setListAdapter(adapter);
}
});
}
}
}
我居然在AllProductsActivity文件有MyAdapter，但爲了便於觀察，我就會把它單獨在這裏：
public class MyAdapter extends ArrayAdapter<MyItem>{
Context context;
int resourceId;
ArrayList<MyItem> items = null;
LayoutInflater inflater;
public MyAdapter (Context context, int resourceId, ArrayList<MyItem> items)
{
super(context, resourceId, items);
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public View getView(int position, View convertView, ViewGroup parent){
final ViewHolder holder;
if (convertView == null){
convertView = inflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.name = (TextView)convertView.findViewById(R.id.name);
holder.video = (VideoView)convertView.findViewById(R.id.videoView);
convertView.setTag(holder);
} else {
holder = (ViewHolder)convertView.getTag();
}
MyItem item = items.get(position);
if (item != null)
{
// This is where you set up the views.
holder.name.setText(TAG_NAME);
Uri myUri = Uri.parse(TAG_DESCRIPTION);
holder.video.setVideoURI(myUri);
holder.video.seekTo(1);
holder.video.setOnTouchListener(
new View.OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event) {
holder.video.start();
holder.video.requestFocus();
return false;
}
}
);
}
return convertView;
}
public class ViewHolder
{
TextView name;
VideoView video;
}
}
顯示'MyAdapter'刪除'runOnUiThread' – Raghunandan
也嘗試着看看在Vogella教程他是相當不錯 – Manny265