我只是得到了这个，但我的事情发生了一个小问题。 具体来说，在我的thread（）中，我正在设置一个Spinner使用的数组。问题是Spinner完全是在我的thread（）完成之前设置和完成的，因此它使用null数组设置自己。
如何将微调器ArrayAdapter与另一个线程正在加载的数组相关联？
我已将代码缩减到我认为理解问题的必要条件，但只是让我知道是否需要更多代码。无论是否调用refreshData（），都会出现问题。
同样，有时我想从菜单中调用loadData（）。如果我尝试在下一行触发吐司，则直接跟随loadData（），这会导致forceclose，这也是因为我正在实现ProgressDialog。
感谢您的光临
public class CMSHome extends Activity {
private static List<String> pmList = new ArrayList<String>();
// Instantiate helpers
PMListHelper plh = new PMListHelper();
ProjectObjectHelper poc = new ProjectObjectHelper();
// These objects hold lists and methods for dealing with them
private Employees employees;
private Projects projects;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Loads data from filesystem, or webservice if necessary
loadData();
// Capture spinner and associate pmList with it through ArrayAdapter
spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
this, android.R.layout.simple_spinner_item,
pmList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
//---the button is wired to an event handler---
Button btn1 = (Button)findViewById(R.id.btnGetProjects);
btn1.setOnClickListener(btnListAllProjectsListener);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
}
private void loadData()
{
final ProgressDialog pd = ProgressDialog.show(this,
"Please wait", "Loading Data...", true, false);
new Thread(new Runnable(){
public void run(){
employees = plh.deserializeEmployeeData();
projects = poc.deserializeProjectData();
// Check to see if data actually loaded, if not then refresh
if ((employees == null) || (projects == null)) {
refreshData();
}
// Load up pmList for spinner control
pmList = employees.getPMList();
pd.dismiss();
}
}).start();
}
private void refreshData()
{
// Refresh data for Projects
projects = poc.refreshData();
poc.saveProjectData(mCtx, projects);
// Refresh data for PMList
employees = plh.refreshData();
plh.savePMData(mCtx, employees);
}
}
＆lt; ---- EDIT -----＆gt; 在Jims的建议之后，我尝试将onCreate（）更改为以下内容。不确定我是否做得对，仍然不起作用：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mCtx = this;
// Loads data from filesystem, or webservice if necessary
// Would like to extend this to update if files are over x days old
final ProgressDialog pd = ProgressDialog.show(this,
"Please wait", "Loading Data...", true, false);
new Thread(new Runnable(){
public void run(){
employees = plh.deserializeEmployeeData();
projects = poc.deserializeProjectData();
// Check to see if data actually loaded, if not then refresh
if ((employees == null) || (projects == null)) {
refreshData();
}
pd.dismiss();
runOnUiThread(new Runnable() {
public void run(){
// Load up pmList for spinner control
pmList = employees.getPMList();
}
});
}
}).start();
spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
this, android.R.layout.simple_spinner_item, pmList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
//---the button is wired to an event handler---
Button btn1 = (Button)findViewById(R.id.btnGetProjects);
btn1.setOnClickListener(btnListAllProjectsListener);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
}
使用后台线程更新Spinner可以通过使用处理程序来完成。在完成线程的主要工作后调用处理程序。
mProgressDlg = ProgressDialog.show(this, "App_Name", "Loading data...",
true, false);
new Thread(new Runnable(){
public void run() {
/*Load Data, set pmList in my case*/
mProgressDlg.dismiss();
hRefresh.sendEmptyMessage(REFRESH);
}
}).start();
Handler hRefresh = new Handler(){
@Override
public void handleMessage(Message msg) {
switch(msg.what){
case REFRESH:
spinner = (Spinner) findViewById(R.id.spinner);
final ArrayAdapter<String> adapter = new ArrayAdapter<String>(
mCtx, android.R.layout.simple_spinner_item, pmList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
break;
}
}
};
归功于bhatt4982及其对this thread
的回答答案 0 :(得分：3)
不知道你是否曾经解决过这个问题，但这对我有用：
public class Start extends Activity {
private static final String TAG = "PriceList";
ArrayAdapter<ProductCategory> category_adapter;
ArrayAdapter<ProductGroup> group_adapter;
ArrayList<ProductCategory> categories;
ArrayList<ProductGroup> groups;
ArrayList<Price> prices;
Spinner group_spinner;
Spinner category_spinner;
ProgressDialog progressDialog;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
group_spinner = (Spinner) findViewById(R.id.group_spinner);
category_spinner = (Spinner) findViewById(R.id.category_spinner);
// product category spinner
categories = new ArrayList<ProductCategory>();
category_adapter = new CustomArrayAdapter<ProductCategory>(categories);
category_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// load category spinner from database
loadCategory(); // adapter MUST be setup before this is called
category_spinner.setAdapter(category_adapter);
category_spinner.setOnItemSelectedListener(new OnItemSelectedListener () {
..... other stuff ......
private final Handler handler = new Handler() {
@Override
public void handleMessage(final Message msg) {
Log.v(TAG, "worker thread done, setup adapter");
switch (msg.what) {
case Constants.CATEGORIES:
category_adapter.notifyDataSetChanged();
break;
case Constants.GROUPS:
group_adapter.notifyDataSetChanged();
break;
case Constants.PRICES:
startActivity(new Intent(Start.this, ShowPrices.class));
break;
default:
}
// dismiss dialog
progressDialog.dismiss();
}
};
// loadCategory() essentially the same....
private void loadGroup(final String cat) {
Log.v(TAG, "loadGroup");
progressDialog = new ProgressDialog(this);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.setMessage("Retrieving Product Groups...");
progressDialog.setMax(100);
progressDialog.setProgress(0);
progressDialog.show();
new Thread() {
@Override
public void run() {
int count = 100;
int i = 0;
SQLiteDatabase db = DbUtils.getStaticDb();
Cursor c = db.rawQuery("select count(*) from productgroup where category = \'"
+ cat + "\';", null);
c.moveToFirst();
if (!c.isAfterLast()) {
count = c.getInt(0);
}
c.close();
progressDialog.setMax(count);
groups.clear();
groups.add(new ProductGroup("-1", "--- Select ---"));
StringBuilder sb = new StringBuilder("select _id,description from productgroup");
sb.append(" where category = \'");
sb.append(cat);
sb.append("\' order by description;");
Log.v(TAG, sb.toString());
c = db.rawQuery(sb.toString(), null);
c.moveToFirst();
while (!c.isAfterLast()) {
Log.v(TAG, c.getString(0));
groups.add(new ProductGroup(c.getString(0), c.getString(1)));
i++;
if (i % 5 == 0) {
progressDialog.setProgress(i);
}
c.moveToNext();
}
c.close();
// tell UI thread OK
handler.sendEmptyMessage(Constants.GROUPS);
}
}.start();
}
// custom ArrayAdapter allows us to have our own ArrayList<T>
class CustomArrayAdapter<T> extends ArrayAdapter<T> {
CustomArrayAdapter(ArrayList<T> list) {
super(Start.this, android.R.layout.simple_spinner_item, list);
}
}
答案 1 :(得分：0)
onCreate（）中loadData（）之后的所有工作都需要在loadData（）中触发的线程中的run（）工作完成后完成。尝试内联loadData（），并在pd.dismiss（）之后将此安装后工作添加到runOnUiThread（）。
答案 2 :(得分：0)
我还建议您使用https://github.com/commonsguy/cwac-task 它有非常好的AsyncTaskEx impl，你可以用来做大量工作而不用锁定ui。
示例类;
protected class DoHeavyWorkAsync extends AsyncTaskEx<Void, Integer, String> {
private static final String TAG = "DoHeavyWorkAsync";
@Override
protected String doInBackground(Void... arg0) {
// do heavy work here. e.g. loadDataFromSomewhere();
YourActivity.this.runOnUiThread(new Runnable() {
public void run() {
// you can do ui work on the main activity from here
}
});
return null;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
Log.d(TAG, "onPreExecute()");
//e.g. display "loading..."
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.d(TAG, "onPostExecute()");
}
}
来自您的主要活动，您可以这样打电话;
(new DoHeavyWorkAsync()).execute();