我对using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
namespace testLock
{
class Program
{
public static void Main()
{
// Start a thread that calls a parameterized static method.
for(int i = 0; i< 10;i++)
{
Thread newThread = new Thread(DoWork);
newThread.Start(i);
}
Console.ReadLine();
}
static object gObject= new object();
public static void DoWork(object data)
{
int len = (int)data % 3;
object tmp = new object();
Console.WriteLine("to lock...... Data='{0}' sleepTime:{1}", data, len);
lock (tmp)//tmp won't work, change tmp to gObject to see different output, which is good locking case)
{
Console.WriteLine("in lock...... Data='{0}' sleepTime:{1}", data, len);
Thread.Sleep( len* 1000);
Console.WriteLine("Static thread procedure. Data='{0}' sleepTime:{1}", data, len);
}
}
}
}
**Lock temp variable,will output:**
to lock...... Data='1' sleepTime:1
in lock...... Data='1' sleepTime:1
to lock...... Data='2' sleepTime:2
in lock...... Data='2' sleepTime:2
to lock...... Data='0' sleepTime:0
in lock...... Data='0' sleepTime:0
Static thread procedure. Data='0' sleepTime:0
to lock...... Data='3' sleepTime:0
in lock...... Data='3' sleepTime:0
Static thread procedure. Data='3' sleepTime:0
to lock...... Data='4' sleepTime:1
in lock...... Data='4' sleepTime:1
to lock...... Data='5' sleepTime:2
in lock...... Data='5' sleepTime:2
to lock...... Data='6' sleepTime:0
in lock...... Data='6' sleepTime:0
Static thread procedure. Data='6' sleepTime:0
to lock...... Data='7' sleepTime:1
in lock...... Data='7' sleepTime:1
to lock...... Data='8' sleepTime:2
in lock...... Data='8' sleepTime:2
to lock...... Data='9' sleepTime:0
in lock...... Data='9' sleepTime:0
Static thread procedure. Data='9' sleepTime:0
Static thread procedure. Data='1' sleepTime:1
Static thread procedure. Data='4' sleepTime:1
Static thread procedure. Data='7' sleepTime:1
Static thread procedure. Data='2' sleepTime:2
Static thread procedure. Data='5' sleepTime:2
Static thread procedure. Data='8' sleepTime:2
**Then lock gObject, will print:**
to lock...... Data='0' sleepTime:0
in lock...... Data='0' sleepTime:0
to lock...... Data='1' sleepTime:1
to lock...... Data='2' sleepTime:2
Static thread procedure. Data='0' sleepTime:0
in lock...... Data='1' sleepTime:1
to lock...... Data='3' sleepTime:0
to lock...... Data='4' sleepTime:1
to lock...... Data='5' sleepTime:2
to lock...... Data='6' sleepTime:0
to lock...... Data='7' sleepTime:1
to lock...... Data='8' sleepTime:2
to lock...... Data='9' sleepTime:0
Static thread procedure. Data='1' sleepTime:1
in lock...... Data='5' sleepTime:2
Static thread procedure. Data='5' sleepTime:2
in lock...... Data='9' sleepTime:0
Static thread procedure. Data='9' sleepTime:0
in lock...... Data='2' sleepTime:2
Static thread procedure. Data='2' sleepTime:2
in lock...... Data='8' sleepTime:2
Static thread procedure. Data='8' sleepTime:2
in lock...... Data='7' sleepTime:1
Static thread procedure. Data='7' sleepTime:1
in lock...... Data='4' sleepTime:1
Static thread procedure. Data='4' sleepTime:1
in lock...... Data='3' sleepTime:0
Static thread procedure. Data='3' sleepTime:0
in lock...... Data='6' sleepTime:0
Static thread procedure. Data='6' sleepTime:0
的使用存有疑问。
就我而言，我调用自己的类Loader并返回AsyncTaskLoader的MyObject。
List 我的问题是：我可以在同一public class MyActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<List<MyObject>> {
@Override
protected void onCreate(Bundle savedInstanceState) {
...
getLoaderManager().initLoader(1, null, this);
getLoaderManager().initLoader(2_ID, null, this);
getLoaderManager().initLoader(3_ID, null, this);
...
}
}
上同时运行多个Loader吗？
每个Loader在Activity方法完成后，是否会调用我loadInBackground()中的onLoadFinished()方法？
提前谢谢。
答案 0 :(得分：1)
是的，我们可以在一个具有唯一ID的活动中一次运行多个加载器，因为Loader是一个异步过程。请在下面找到示例模板。
public class SampleActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sample);
initLoaders();
}
private void initLoaders() {
getLoaderManager().initLoader(1, null, null);
getLoaderManager().initLoader(2, null, null);
getLoaderManager().initLoader(3, null, null);
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
CursorLoader cursorLoader = null;
switch (id) {
case 1:
cursorLoader = new CursorLoader(this, CONTENT_URI,
PROJECTION, selection, null, null);
break;
case 2:
cursorLoader = new CursorLoader(this, CONTENT_URI,
PROJECTION, selection, null, null);
break;
case 3:
cursorLoader = new CursorLoader(this, CONTENT_URI,
PROJECTION, selection, null, null);
break;
}
return cursorLoader;
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
switch (loader.getId()) {
case 1:
if (data != null && data.getCount() > 0)
setData1();
break;
case 2:
if (data != null && data.getCount() > 0)
setData2();
break;
case 3:
if (data != null && data.getCount() > 0)
setData3();
break;
}
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
}
}