我是Android新手,并且一直在使用AndroidHive教程,该教程加载了一系列产品"从远程数据库中将其显示在列表视图中。我有教程运行,它非常好,但我想修改它在gridview而不是listview中显示数据,我不知道如何。这是我正在使用的代码。
public class TimeTableActivity extends Activity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> modulesList;
// url to get all modules list
private static String url_all_modules = " http://<MyIPAddress>/timetable/get_all_modules.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_MODULES = "modules";
private static final String TAG_MODID = "modid";
private static final String TAG_MODULE_NAME = "module_name";
private static final String TAG_DAY = "day";
// modules JSONArray
JSONArray modules = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.time_table);
// Hashmap for ListView
modulesList = new ArrayList<HashMap<String, String>>();
// Loading modules in Background Thread
new LoadAllmodules().execute();
GridView grid = (GridView) findViewById(R.id.mygrid);
// on seleting single product
// launching Edit Product Screen
grid.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Starting new intent
//Intent in = new Intent(getApplicationContext(),
// TimeTableActivity.class);
// sending modid to next activity
//in.putExtra(TAG_MODID, modid);
// starting new activity and expecting some response back
//startActivityForResult(in, 100);
}
});
}
// 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 LoadAllmodules extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(TimeTableActivity.this);
pDialog.setMessage("Loading Time Table. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All modules from url
* */
@Override
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_modules, "GET", p arams);
// Check your log cat for JSON reponse
Log.d("ALL MODULES: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// modules found
// Getting Array of modules
modules = json.getJSONArray(TAG_MODULES);
// looping through All modules
for (int i = 0; i < modules.length(); i++) {
JSONObject c = modules.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_MODID);
String day = c.getString(TAG_DAY);
String name = c.getString(TAG_MODULE_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_MODID, id);
map.put(TAG_DAY, day);
map.put(TAG_MODULE_NAME, name);
// adding HashList to ArrayList
modulesList.add(map);
}
} else {
Toast.makeText(getApplicationContext(), "Time Table cannot be displayed right now",
Toast.LENGTH_LONG).show();
// no modules 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
* **/
@Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all modules
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
@Override
public void run() {
/**
* Updating parsed JSON data into ListView
* */
GridView grid = (GridView) findViewById(R.id.mygrid);
ListAdapter adapter = new SimpleAdapter(
TimeTableActivity.this, modulesList,
R.layout.tt_item, new String[] { TAG_MODID, TAG_DAY,
TAG_MODULE_NAME},
new int[] { R.id.modid, R.id.day, R.id.name});
// updating listview
grid.setAdapter(adapter);
}
});
}
}}
&lt; ----- XML tt_item ------&gt;假设我不必修改此
<TextView
android:id="@+id/modid"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<!-- Name Label -->
<TextView
android:id="@+id/day"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="6dip"
android:paddingLeft="6dip"
android:textSize="17sp"
android:textStyle="bold" />
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="6dip"
android:paddingLeft="6dip"
android:textSize="17sp"
android:textStyle="bold" />
&lt; ---- XML time_table -----&gt;假设我只需要更改为标准gridview
<GridView
android:id="@+id/mygrid"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:numColumns="2"
android:stretchMode="columnWidth" />
任何帮助都会非常感激,因为我真的不知道如何解决这个问题。
答案 0 :(得分:0)
这很简单。您必须进行一些更改,如下所示:
将ListActivity
更改为Activity
将GridView变量初始化为GridView grid;
此ListView lv = getListView();
应为grid = (GridView) findViewById(R.id.mygrid)
因此lv.setOnItemClickListener(...)
应为grid.setOnItemClickListener(...)
然后,此setListAdapter(adapter);
变为grid.setAdapter(adapter)
最后,你的布局是:
<GridView
android:id="@+id/mygrid"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:numColumns="2"
android:stretchMode="columnWidth" />
您可以选择android:columnWidth
列的宽度和android:numColumns
的数字。由于android:stretchMode
用于控制物品如何拉伸以填充其空间。您可以在Documentation找到一个简单的教程
希望这会有所帮助。
编辑:
你总是需要在{/ 1}}方法中使用findViewById
方法而不是之前的。使用此:
onCreate
更新:
findViewById()可以在其他方法中调用,如public class TimeTableActivity extends Activity {
// init a variable
GridView grid;
// Then, in onCreate method find its id
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.time_table);
// find the view
grid = (GridView) findViewById(R.id.mygrid);
}
// ...
// Finally, in onPostExecute method, reuse the SAME variable as above
@Override
protected void onPostExecute(String file_url) {
// ...
// reuse *grid*
grid.setAdapter(adapter);
}
}
,onAttach
等 - (抱歉我的语法错误)。因此,作为上面的代码,您可以避免创建var。所以你只需要这样做(在某种程度上更快):
onDestroy
在onPostExecute()中。