我正在从Web服务获取GridView的图像和文本，因此显示GridView需要一些时间。我想显示一个ProgressDialog，直到网格完全加载。到目前为止，我所做的如下：
public class PCGridMain extends Activity
{
WebService web = new WebService();
private GridView gridView;
ProgressDialog dialog;
Bitmap icon;
int i, total;
URL url= null;
List<GridItem> list;
@Override
public void onCreate(Bundle grid)
{
super.onCreate(grid);
dialog = ProgressDialog.show(PCGridMain.this, "Loading...", "Loading App, Please wait.", true);
DialogWork dWork = new DialogWork();
dWork.execute();
setContentView(R.layout.main);
gridView = (GridView)findViewById(R.id.gridView1);
web.WebService1();
total = web.totalService;
list = new ArrayList<GridItem>();
for(i=0; i<total; i++)
{
Log.v("Try Block", "See what we get:-");
try
{
Log.v("GridMain", "try url" + Integer.toString(i));
url = new URL(web.arr[i][2]);
}
catch (MalformedURLException e)
{
Log.v("GridMain", "catch MalformedURLException" + Integer.toString(i));
e.printStackTrace();
}
try
{
Log.v("GridMain", "try BitmapFactory" + Integer.toString(i));
icon = BitmapFactory.decodeStream(url.openConnection().getInputStream());
}
catch (IOException e)
{
Log.v("GridMain", "catch IOException" + Integer.toString(i));
e.printStackTrace();
}
list.add(new GridItem(icon, web.arr[i][1])); // Adding Icon & LAbel
}
gridView.setAdapter(new GridAdapter(this, list));
gridView.setOnItemClickListener(Itemlistener);
}
private OnItemClickListener Itemlistener = new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long id)
{
ViewHolder holder = (ViewHolder)view.getTag();
if(holder == null)
{
return;
}
Toast.makeText(PCGridMain.this, holder.label.getText(), Toast.LENGTH_SHORT).show();
Log.v("GridMain", "Intent Creation");
Intent intent = new Intent(view.getContext(), ShowService.class); Log.v("GridMain", "Intent Created");
intent.putExtra("ServiceId", web.arr[position][0]); Log.v("GridMain", "ValueAdded Sid");
intent.putExtra("SName", holder.label.getText()); Log.v("GridMain", "ValueAdded SName");
startActivity(intent);
}
};
class DialogWork extends AsyncTask<URL, Integer, Long>
{
protected Long doInBackground(URL... params)
{
try
{
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
protected void onProgressUpdate(Integer... progress)
{
}
protected void onPostExecute(Long result)
{
try
{
//setContentView(R.layout.main);
//gridView.setAdapter(new GridAdapter(PCGridMain.this, list));
dialog.dismiss();
}
catch (Exception e)
{
e.printStackTrace();
dialog.dismiss();
}
}
}
请告诉我，什么代码必须放在什么确切的位置，每当我做一些更改时，它要么没有显示效果，要么应用程序因某些问题关闭。
谢谢，
Haps。
尝试将服务器中的所有渲染部分放在doInBackground（）中，并将适配器设置在onPostExecute（）中。甚至在中的onPreExecute（）中启动progress对话框，并在onPostExecute（。我认为这会解决你的问题。。。。
这应该是您的内部AsyncTask类，根据需要更改参数。
private class yourTask extends AsyncTask<Void, Void, ArrayList> {
String message;
ProgressDialog dialog;
public refreshTask(String message) {
this.message = message;
this.dialog = new ProgressDialog(PCGridMain.this);
}
@Override
protected void onPreExecute() {
dialog.setMessage(message);
dialog.setIndeterminate(true);
dialog.setCancelable(true);
dialog.show();
}
@Override
protected ArrayList doInBackground(String... params) {
// Some work
}
@Override
protected void onPostExecute(ArrayList result) {
if(dialog.isShowing())
dialog.dismiss();
}
}
所以你可以这样称呼这个类：
new yourTask('Dialog message').execute();
我希望它能解决你的问题。
这里我给出了我的问题的完整答案，这样可以帮助其他人轻松完成。。。
public class PCGridMain extends Activity
{
WebService web = new WebService();
private GridView gridView;
ProgressDialog dialog;
Bitmap icon;
int i, total;
URL url= null;
List<GridItem> list;
@Override
public void onCreate(Bundle grid)
{
super.onCreate(grid);
Log.v("GridMain", "setContent");
setContentView(R.layout.main);
gridView = (GridView)findViewById(R.id.gridView1);
DialogWork dWork = new DialogWork();
dWork.execute();
}
private void ForLoop()
{
for(i=0; i<total; i++)
{
Log.v("Try Block", "See what we get:-");
try
{
Log.v("GridMain", "try url" + Integer.toString(i));
url = new URL(web.arr[i][2]);
}
catch (MalformedURLException e)
{
Log.v("GridMain", "catch MalformedURLException" + Integer.toString(i));
e.printStackTrace();
}
try
{
Log.v("GridMain", "try BitmapFactory" + Integer.toString(i));
icon = BitmapFactory.decodeStream(url.openConnection().getInputStream());
}
catch (IOException e)
{
Log.v("GridMain", "catch IOException" + Integer.toString(i));
e.printStackTrace();
}
list.add(new GridItem(icon, web.arr[i][1])); // Adding Icon & LAbel
}
}
private OnItemClickListener Itemlistener = new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long id)
{
ViewHolder holder = (ViewHolder)view.getTag();
if(holder == null)
{
return;
}
Toast.makeText(PCGridMain.this, holder.label.getText(), Toast.LENGTH_SHORT).show();
Log.v("GridMain", "Intent Creation");
Intent intent = new Intent(view.getContext(), ShowService.class); Log.v("GridMain", "Intent Created");
intent.putExtra("ServiceId", web.arr[position][0]); Log.v("GridMain", "ValueAdded Sid");
intent.putExtra("SName", holder.label.getText()); Log.v("GridMain", "ValueAdded SName");
startActivity(intent);
}
};
class DialogWork extends AsyncTask<URL, Integer, String>
{
protected void onPreExecute()
{
Log.v("GridMain", "PreExecute()");
dialog = ProgressDialog.show(PCGridMain.this, "Loading...", "Loading App, Please wait.", false, true);
}
protected Long doInBackground(URL... params)
{
String response = "";
try
{
Log.v("GridMain", "doInBackground");
response = web.WebService1();
total = web.totalService;
}
catch (InterruptedException e)
{
Log.v("GridMain", "InterruptedException");
e.printStackTrace();
}
return response;
}
protected void onPostExecute(String result)
{
try
{
// Response is in RESULT_VAR
Log.v("GridMain", "onPostExecute");
list = new ArrayList<GridItem>();
ForLoop();
gridView.setAdapter(new GridAdapter(PCGridMain.this, list));
gridView.setOnItemClickListener(Itemlistener);
dialog.dismiss();
}
catch (Exception e)
{
Log.v("GridMain", "Exception e");
e.printStackTrace();
dialog.dismiss();
}
}
}
}
我根据自己的需要使用了它，只是为了提供帮助，完整的代码可能会给你带来问题。所以把它作为参考。
谢谢&问候，
Haps。
尝试使用此代码进行对话框，否则代码似乎可以工作
dialog= new ProgressDialog(this);
dialog.setMessage("Loading");
dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
dialog.setCancelable(false);
dialog.show();