您好 Android 开发者,
活动重新启动后,我面临一些视图的奇怪行为 - 有些视图不是“可见的”,但它们是经过布局的并对触摸动作做出反应。
我试图让应用程序遵循 Android 生命周期指南。我将 Activity 放到后台并让系统关闭我的 Activity。然后我导航回我的活动,该活动被重新创建。要损坏的数据没有问题(每次更改都保存在数据库中),但视图是。有一些正确显示,但TableView内的所有内容(位于ScrollView内)都不可见。如果我在任何未显示的视图上调用getVisibility(),我就会知道它是可见的。正如我上面提到的,视图不是“可见的”,而是对触摸和滚动事件做出反应,就像它们被正确显示一样。
这也很难(不可能)调试,因为当应用程序关闭时,调试器断开连接。但是无论如何,娱乐遵循相同的回调方法- onCreate(),onStart(),onResume(),所以一旦创建,为什么其他时间会出现问题?对我来说唯一的区别是,新创建 Activity 时onCreate(Bundle)中有一个null Bundle,而系统重新创建它时不为 null。如果活动仅停止(在后台)但没有被系统关闭,则一切正常。
我还尝试覆盖onSaveInstanceState()和onRestoreInstanceState()没有任何东西可以保存和恢复(没有调用超级实现),但它没有效果。
我正在使用 Android 4.1.1 和模拟器 2.1。
有人有什么主意吗?
谢谢啤酒
以下是(链接到)屏幕截图,以便更好地理解:
系统关闭
活动之前 重新创建活动之后
以下是布局文件:
<!-- Header -->
<LinearLayout
android:id="@+id/startlistHeaderLayout" xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView android:id="@+id/textStartlistName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lines="1"
android:gravity="left"
android:text=""
/>
<TextView android:id="@+id/textStarttime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lines="1"
android:gravity="right"
android:text=""
android:layout_weight="1"
/>
</LinearLayout>
<!-- Results -->
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@id/resultsScrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fillViewport="true"
android:saveEnabled="false"
>
<TableLayout
android:id="@id/timingLapTableLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stretchColumns="2"
android:shrinkColumns="2"
android:saveEnabled="false"
>
<!-- rows are added in code -->
</TableLayout>
</ScrollView>
</LinearLayout>
<!-- R.layout.timing_row -->
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@id/timingTableRow"
android:saveEnabled="false"
>
<TextView
android:id="@id/textTimingPosition"
android:text=""
android:gravity="right"
android:paddingLeft="4dip"
android:saveEnabled="false"
/>
<TextView
android:id="@id/textTimingBib"
android:text=""
android:gravity="right"
android:paddingLeft="1dip"
android:saveEnabled="false"
/>
<TextView
android:id="@id/textTimingName"
android:text=""
android:lines="1"
android:ellipsize="end"
android:gravity="left"
android:paddingLeft="1dip"
android:paddingRight="5dip"
android:saveEnabled="false"
/>
<TextView
android:id="@id/textTimingBehind1"
android:text=""
android:gravity="right"
android:paddingRight="5dip"
android:saveEnabled="false"
/>
<TextView
android:id="@id/textTimingBehind2"
android:text=""
android:gravity="right"
android:paddingRight="5dip"
android:saveEnabled="false"
/>
</TableRow>
这是活动代码的一部分:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(null);
loadPreferencesTimingTheme();
if (ownTheme) {
this.setTheme(theme);
} else {
this.setTheme(MainActivity.theme);
}
}
protected void onStart() {
super.onStart();
View lapView;
View v;
int sid;
setContentView(R.layout.startlist_edit);
sid = getIntent().getIntExtra(TimingActivity.STARTLIST_ID, -1);
if (sid == -1) {
Toast.makeText(this, "Sorry, could not load startlist.", Toast.LENGTH_LONG);
this.finish();
return;
}
tdb = new TimingDB(this);
sl = tdb.getStartlist(sid); // get Startlist from db into memory
// hide unnecessary columns
v = findViewById(R.id.timingLapTableLayout);
((TableLayout) v).setColumnCollapsed(0, true);
loadStartlist(sl); // inflate rows with startlist data and set listeners
// load the preferences and set preferences listener
loadPreferences();
PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(prefsChangeListener);
}
public void onStop() {
super.onStop();
PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(prefsChangeListener);
if (tdb != null) tdb.close();
}
protected void onSaveInstanceState (Bundle outState) {
// super.onSaveInstanceState(outState);
}
protected void onRestoreInstanceState (Bundle savedInstanceState) {
// super.onRestoreInstanceState(savedInstanceState);
}
protected void onDestroy() {
super.onDestroy();
if (tdb != null) tdb.close();
}
private void loadStartlist(StartList sl) {
// set startlist name & time
View v = findViewById(R.id.textStarttime);
((TextView) v).setText(SimpleDateFormats.ddmmyyyyhhmmss.format(new Date(sl.getStartTime())));
v = findViewById(R.id.textStartlistName);
((TextView) v).setText(sl.getName());
// set header onclicklistener
v = findViewById(R.id.startlistHeaderLayout);
v.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// show dialog to change startlist name and time
Bundle args = new Bundle();
args.putString(KEY_NAME, ((TextView) findViewById(R.id.textStartlistName)).getText().toString());
args.putString(KEY_STTIME, ((TextView) v.findViewById(R.id.textStarttime)).getText().toString());
if (Build.VERSION.SDK_INT < 8) {
dialogBundle = args;
showDialog(DIALOG_EDIT_STARTLIST);
} else {
showDialog(DIALOG_EDIT_STARTLIST, args);
}
}
});
// add competitors to startlist
int cnt = sl.getCompetitorsCount();
for (int i = 0; i < cnt; i++) {
Competitor c = sl.getCompetitorByIndex(i);
appendStartlistRow(c);
}
}
public void appendStartlistRow(final Competitor c) {
TableRow inflatedView = (TableRow) getLayoutInflater().inflate(R.layout.timing_row, null);
inflatedView.setTag(TAG_COMPETITOR, c);
inflatedView.setTag(new Integer(c.getBib()));
inflatedView.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
TableLayout tl = (TableLayout) findViewById(R.id.timingLapTableLayout);
Bundle args = new Bundle();
args.putInt(KEY_INDEX, tl.indexOfChild(v));
if (Build.VERSION.SDK_INT < 8) {
dialogBundle = args;
showDialog(DIALOG_EDIT_COMPETITOR);
} else {
showDialog(DIALOG_EDIT_COMPETITOR, args);
}
}
});
// set up texts
TextView text = (TextView) inflatedView.findViewById(R.id.textTimingBib);
text.setText(c.getBib() + "");
text = (TextView) inflatedView.findViewById(R.id.textTimingName);
text.setText(c.getName());
text = (TextView) inflatedView.findViewById(R.id.textTimingBehind1);
text.setText(getFormatedStartTime(sl, c, Settings.STARTTIME_ABSOLUTE));
text = (TextView) inflatedView.findViewById(R.id.textTimingBehind2);
text.setText(getFormatedStartTime(sl, c, Settings.STARTTIME_RELATIVE));
// append the row
appendStartlistRow((ViewGroup) inflatedView);
}
public void appendStartlistRow(ViewGroup row) {
// set background and text colors
if (((((Integer) row.getTag()).intValue()) % 2) == Defs.VIEW_EVEN) {
row.setBackgroundColor(Defs.COLOR_BACKGROUND_EVEN);
for (int j = 0; j < row.getChildCount(); j++) {
((TextView) (row.getChildAt(j))).setTextColor(Defs.COLOR_TEXT_EVEN);
}
} else {
row.setBackgroundColor(Defs.COLOR_BACKGROUND_ODD);
for (int j = 0; j < row.getChildCount(); j++) {
((TextView) (row.getChildAt(j))).setTextColor(Defs.COLOR_TEXT_ODD);
}
}
((TableLayout) findViewById(R.id.timingLapTableLayout)).addView(row);
}
Defs.java:
public class Defs {
protected static final int VIEW_EVEN = 0;
protected static final int VIEW_ODD = 1;
protected static int COLOR_BACKGROUND_EVEN;
protected static int COLOR_BACKGROUND_ODD;
protected static int COLOR_BACKGROUND_SELECTED;
protected static int COLOR_BACKGROUND_SPYED;
protected static int COLOR_TEXT_ODD;
protected static int COLOR_TEXT_EVEN;
protected static int COLOR_TEXT_SELECTED;
protected static int COLOR_TEXT_SPYED;
private static boolean isInitialized = false;
protected static void init(Context c) {
if (isInitialized) return;
COLOR_BACKGROUND_EVEN = c.getResources().getColor(R.color.background_darker);
COLOR_BACKGROUND_ODD = c.getResources().getColor(R.color.background_lighter);
COLOR_BACKGROUND_SELECTED = c.getResources().getColor(R.color.background_selected);
COLOR_BACKGROUND_SPYED = c.getResources().getColor(R.color.background_spyed);
COLOR_TEXT_ODD = c.getResources().getColor(R.color.text_lighter);
COLOR_TEXT_EVEN = c.getResources().getColor(R.color.text_darker);
COLOR_TEXT_SELECTED = c.getResources().getColor(R.color.text_selected);
COLOR_TEXT_SPYED = c.getResources().getColor(R.color.text_spyed);
isInitialized = true;
}
}