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我正在嘗試進行要求獲得某些結果的活動。這個結果通常立即返回(在onCreate中),然而,有時候需要等待一些互聯網內容下載,這導致「加載器」活動顯示。我想要的是,加載器活動不會顯示除progressdialog以外的任何內容(並且您仍然可以選擇在後臺調用加載器活動的舊活動),並且我想知道這是否可行。startActivityForResult僅顯示進度對話框的活動
現在,我使用的的代碼是:
//ListComicsActivity.java
public class ListComicsActivity extends Activity
{
private static final int REQUEST_COMICS = 1;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.list_comics);
Button button = (Button)findViewById(R.id.Button01);
button.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setAction(Intents.ACTION_GET_COMICS);
startActivityForResult(intent, REQUEST_COMICS);
}
});
}
/** Called when an activity called by using startActivityForResult finishes. */
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
Toast toast = Toast.makeText(this, "The activity finnished", Toast.LENGTH_SHORT);
toast.show();
}
}
//LoaderActivity.java (answers to Intents.ACTION_GET_COMICS action-filter)
public class LoaderActivity extends Activity
{
private Intent result = null;
private ProgressDialog pg = null;
private Runnable returner = new Runnable()
{
public void run()
{
if(pg != null)
pg.dismiss();
LoaderActivity.this.setResult(Activity.RESULT_OK, result);
LoaderActivity.this.finish();
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
String action = getIntent().getAction();
if(action.equals(Intents.ACTION_GET_COMICS))
{
Runnable loader = new Runnable()
{
public void run()
{
WebProvider.DownloadComicList();
Intent intent = new Intent();
intent.setDataAndType(ComicContentProvider.COMIC_URI, "vnd.android.cursor.dir/vnd.mymir.comic");
returnResult(intent);
}
};
pg = ProgressDialog.show(this, "Downloading", "Please wait, retrieving data....");
Thread thread = new Thread(null, loader, "LoadComicList");
thread.start();
}
else
{
setResult(Activity.RESULT_CANCELED);
finish();
}
}
private void returnResult(Intent intent)
{
result = intent;
runOnUiThread(returner);
}
}
我不明白加載器活動的重點,如果你不想顯示它,爲什麼不把這個可運行的代碼放到一個外部類中,然後在你的調用活動的click事件中啓動呢? – 2010-06-02 18:38:25
關鍵是我可以有不同的裝載機。而且,您可以稍後在不同的應用程序中安裝更多的裝載器。 – Alxandr 2010-06-02 18:39:47