在我的活动中,我有两个片段在右边,一个在左边。在某些时候我需要删除一个并添加另一个。但是当我删除左边时,那个未被移除的片段扩展并且第二个是添加在右边而不是左边。我会给你看一个屏幕截图,这样你就可以理解我的意思。我怎样才能阻止蓝色片段改变位置?
我使用了rightFrag.setRetainInstance(true);
但它不会工作。谢谢你的时间。
public class MainActivity extends SherlockFragmentActivity implements ActionBar.TabListener {
private final Handler handler = new Handler();
private RoundedColourFragment leftFrag1;
private RoundedColourFragment leftFrag2;
private RoundedColourFragment leftFrag3;
private RoundedColourFragment leftFrag4;
private RoundedColourFragment currentFragment =null;
private RightFragment rightFrag;
private boolean useLogo = false;
private boolean showHomeUp = false;
private FragmentTransaction ft;
private static boolean onLoad=true;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ActionBar ab = getSupportActionBar();
// set defaults for logo & home up
ab.setDisplayHomeAsUpEnabled(showHomeUp);
ab.setDisplayUseLogoEnabled(useLogo);
// set up tabs nav
for (int i = 1; i <= 4; i++) {
ab.addTab(ab.newTab().setTabListener(this).setText("Tab "+ i));
}
// set up list nav
ab.setListNavigationCallbacks(ArrayAdapter
.createFromResource(this, R.array.sections,
R.layout.sherlock_spinner_dropdown_item),
new OnNavigationListener() {
public boolean onNavigationItemSelected(int itemPosition,
long itemId) {
// FIXME add proper implementation
rotateLeftFrag();
return false;
}
});
// default to tab navigation
showTabsNav();
// create a couple of simple fragments as placeholders
final int MARGIN = 16;
leftFrag1 = new RoundedColourFragment(getResources().getColor(
R.color.abs__bright_foreground_holo_dark), 1f, MARGIN, MARGIN / 2, MARGIN, MARGIN,R.layout.tab1);
leftFrag2 = new RoundedColourFragment(getResources().getColor(
R.color.abs__bright_foreground_holo_dark), 4f, MARGIN, MARGIN / 2, MARGIN, MARGIN,R.layout.tab2);
leftFrag3 = new RoundedColourFragment(getResources().getColor(
R.color.abs__bright_foreground_holo_dark), 1f, MARGIN, MARGIN / 2, MARGIN, MARGIN,R.layout.tab3);
leftFrag4 = new RoundedColourFragment(getResources().getColor(
R.color.abs__bright_foreground_holo_dark), 1f, MARGIN, MARGIN / 2, MARGIN, MARGIN,R.layout.tab4);
rightFrag = new RightFragment(getResources().getColor(
R.color.honeycombish_blue), 2f, MARGIN / 2, MARGIN, MARGIN,
MARGIN);
ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.root, leftFrag1);
ft.add(R.id.root, rightFrag);
ft.commit();
onLoad=false;
currentFragment=leftFrag1;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getSupportMenuInflater().inflate(R.menu.main_menu, menu);
// set up a listener for the refresh item
final MenuItem refresh = (MenuItem) menu.findItem(R.id.menu_refresh);
refresh.setOnMenuItemClickListener(new OnMenuItemClickListener() {
// on selecting show progress spinner for 1s
public boolean onMenuItemClick(MenuItem item) {
// item.setActionView(R.layout.progress_action);
handler.postDelayed(new Runnable() {
public void run() {
refresh.setActionView(null);
}
}, 1000);
return false;
}
});
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// TODO handle clicking the app icon/logo
return false;
case R.id.menu_refresh:
// switch to a progress animation
item.setActionView(R.layout.indeterminate_progress_action);
return true;
case R.id.menu_both:
// rotation animation of green fragment
rotateLeftFrag();
return true;
case R.id.menu_text:
// alpha animation of blue fragment
ObjectAnimator alpha = ObjectAnimator.ofFloat(rightFrag.getView(),
"alpha", 1f, 0f);
alpha.setRepeatMode(ObjectAnimator.REVERSE);
alpha.setRepeatCount(1);
alpha.setDuration(800);
alpha.start();
return true;
case R.id.menu_logo:
useLogo = !useLogo;
item.setChecked(useLogo);
getSupportActionBar().setDisplayUseLogoEnabled(useLogo);
return true;
case R.id.menu_up:
showHomeUp = !showHomeUp;
item.setChecked(showHomeUp);
getSupportActionBar().setDisplayHomeAsUpEnabled(showHomeUp);
return true;
case R.id.menu_nav_tabs:
item.setChecked(true);
showTabsNav();
return true;
case R.id.menu_nav_label:
item.setChecked(true);
showStandardNav();
return true;
case R.id.menu_nav_drop_down:
item.setChecked(true);
showDropDownNav();
return true;
case R.id.menu_bak_none:
item.setChecked(true);
getSupportActionBar().setBackgroundDrawable(null);
return true;
case R.id.menu_bak_gradient:
item.setChecked(true);
getSupportActionBar().setBackgroundDrawable(getResources().getDrawable(R.drawable.ad_action_bar_gradient_bak));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void rotateLeftFrag() {
if (currentFragment!= null) {
ObjectAnimator.ofFloat(currentFragment.getView(), "rotationY",0,360).setDuration(500).start();
}
}
private void showStandardNav() {
ActionBar ab = getSupportActionBar();
if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_STANDARD) {
ab.setDisplayShowTitleEnabled(true);
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
}
}
private void showDropDownNav() {
ActionBar ab = getSupportActionBar();
if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_LIST) {
ab.setDisplayShowTitleEnabled(false);
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
}
}
private void showTabsNav() {
ActionBar ab = getSupportActionBar();
if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_TABS) {
ab.setDisplayShowTitleEnabled(false);
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
}
}
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
// FIXME add a proper implementation, for now just rotate the left
// fragment
System.out.println(tab.getPosition());
if(!onLoad){
ft = getSupportFragmentManager().beginTransaction();
ft.remove(currentFragment);
if(tab.getPosition()==0){
ft.add(R.id.root, leftFrag1);
currentFragment=leftFrag1;
}else if(tab.getPosition()==1){
ft.add(R.id.root, leftFrag2);
currentFragment=leftFrag2;
}else if(tab.getPosition()==2){
ft.add(R.id.root, leftFrag3);
currentFragment=leftFrag3;
}else{
ft.add(R.id.root, leftFrag4);
currentFragment=leftFrag4;
}
ft.commit();
// rotateLeftFrag();
}
}
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
// FIXME implement this
}
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
// FIXME implement this
}
}
我还有另外两个与片段有关的课程,如果你认为我应该发布它们,请告诉我。