if (!r.activity.mFinished && willBeVisible

&& r.activity.mDecor != null && !r.hideForNow) {

if (r.newConfig != null) {

if (DEBUG_CONFIGURATION) Slog.v(TAG, "Resuming activity "

+ r.activityInfo.name + " with newConfig " + r.newConfig);

performConfigurationChanged(r.activity, r.newConfig);

r.newConfig = null;

}

if (localLOGV) Slog.v(TAG, "Resuming " + r + " with isForward="

+ isForward);

WindowManager.LayoutParams l = r.window.getAttributes();

if ((l.softInputMode

& WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION)

!= forwardBit) {

l.softInputMode = (l.softInputMode

& (~WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION))

| forwardBit;

if (r.activity.mVisibleFromClient) {

ViewManager wm = a.getWindowManager();

View decor = r.window.getDecorView();

wm.updateViewLayout(decor, l);

}

}

r.activity.mVisibleFromServer = true;

mNumVisibleActivities++;

if (r.activity.mVisibleFromClient) {

r.activity.makeVisible();

}

}

r.nextIdle = mNewActivities;

mNewActivities = r;

if (localLOGV) Slog.v(

TAG, "Scheduling idle handler for " + r);

Looper.myQueue().addIdleHandler(new Idler());

} else {

// If an exception was thrown when trying to resume, then

// just end this activity.

try {

ActivityManagerNative.getDefault()

.finishActivity(token, Activity.RESULT_CANCELED, null);

} catch (RemoteException ex) {

}

}

}

最后，提个问题结束吧：activity.onStart里通过线程刷新UI能成功吗？别回答太快哟！好好想想！