I'm developing an Android app using Xamarin studio, but this is not important.
I use the pageViewer to upload the fragment (12 more or less). To the one display fragment i use a webView to display a local html page and with a swipe to the left, the webview content change to the next one.
So, at the fifth frgament memory problems started even if i used different tasks in my code.
My question is: Is there a way to 'detach' the fragment when i'm not displaying them? Can they not remain into my memory?
Thanks for all
This is my code, N.B: Java answers are accepeted as well
protected override void OnCreate (Bundle bundle)
{
base.OnCreate (bundle);
SetContentView (Resource.Layout.BookView);
_loader = ProgressDialog.Show (this, "Loading...", "Please wait...", true);
//return chapters count
chapters = 12 //example
//var dp = (int)Resources.DisplayMetrics.Density;
_layout = FindViewById<DrawerLayout> (Resource.Id.drawer_layout);
_view = FindViewById<ViewPager>(Resource.Id.bView);
_view.SetBackgroundColor (Color.White);
_currentAdapter = new AwesomeFragmentAdapter (SupportFragmentManager, path, name, chapters, this, _view);
_view.Adapter = _currentAdapter;
_view.OffscreenPageLimit = chapters;
List<int> positions = new List<int> ();
_view.PageSelected += (object sender, ViewPager.PageSelectedEventArgs e) => {
//get details
var page_load = new Task (() => {
//return an object with the chapter details
_chap = object;
});
page_load.Start();
//find the webview
_web = (WebView)_view.FindViewWithTag(300 + e.Position);
WebSettings setting = _web.Settings;
setting.CacheMode = CacheModes.Default;
setting.JavaScriptEnabled = true;
setting.BuiltInZoomControls = true;
setting.DisplayZoomControls = false;
setting.PluginsEnabled = true;
setting.SetPluginState(WebSettings.PluginState.On);
//setting.JavaScriptCanOpenWindowsAutomatically = true;
if (positions.Contains(e.Position)) {
_web.ClearCache(true);
_web.ClearView();
}
//Start when the scroll is finished
_view.PageScrollStateChanged += (object sendero, ViewPager.PageScrollStateChangedEventArgs ex) => {
if (ex.State == 0 ) {
if (positions.Contains(e.Position)) {
//_web.Reload(); --> doesn't work
//Doesn't reload the .js animations
_web.LoadUrl ("file://" + path + "/" + _chap.Name);
} else {
_web.LoadUrl ("file://" + path + "/" + _chap.Name);
positions.Add(e.Position);
}
}
};
};
}
public class BWebClient : WebViewClient
{
int _position;
string _path;
Activity _parent;
ViewPager _pager;
string _chapName;
public BWebClient (int position, string Path, Activity Parent, ViewPager Pager, string ChapName){
_position = position;
_parent = Parent;
_path = Path;
_pager = Pager;
_chapName = ChapName;
}
public override void OnPageFinished (WebView view, string url)
{
base.OnPageFinished (view, url);
view.ScrollTo (0, _position);
}
public override bool ShouldOverrideUrlLoading (WebView view, string url)
{
if (url.StartsWith ("navigate")) {
string destination = url.Substring (url.IndexOf ("navigate://") + "navigate://".Length);
int DestinationChapter = Int32.Parse (destination.Substring (0, destination.IndexOf("_")));
int l = destination.IndexOf("_") + 1;
int b = destination.Length - l;
int DestinationPage = Int32.Parse (destination.Substring (l,b));
if (DestinationPage == 0) {
_pager.SetCurrentItem(DestinationChapter ,true);
WebView _web = (WebView)_pager.FindViewWithTag(300 + DestinationChapter);
_web.LoadUrl ("file://" + _path + "/" + _chapName);
}
} else if (url.StartsWith ("pdf")) {
string file_path = System.IO.Path.Combine (_path, url.Substring (url.IndexOf ("pdf://") + "pdf://".Length));
Android.Net.Uri pdfFile = Android.Net.Uri.FromFile (new Java.IO.File (file_path));
Intent pdfIntent = new Intent (Intent.ActionView);
pdfIntent.SetDataAndType (pdfFile, "application/pdf");
_parent.StartActivity (pdfIntent);
}
return true;
}
}
public class AwesomeFragmentAdapter : FragmentPagerAdapter
{
string _path;
string _filename;
int _chapters;
Activity _parent;
FileUtilities _fUtils;
ViewPager _pager;
public AwesomeFragmentAdapter (Android.Support.V4.App.FragmentManager fm,
string path,
string filename,
int chapters,
Activity parent,
FileUtilities FUtils,
ViewPager Pagers): base(fm)
{
_path = path;
_filename = filename;
_chapters = chapters;
_parent = parent;
_fUtils = FUtils;
_pager = Pagers;
}
public override int Count
{
/* --- return chapter count --- */
get { return _chapters;}
}
public override Android.Support.V4.App.Fragment GetItem(int _position)
{
/* --- get specific item --- */
return new AwesomeFragment (_path, _filename, _position, _parent, _fUtils, _pager);
}
}
public class AwesomeFragment : Android.Support.V4.App.Fragment
{
string _path;
WebView web_view;
string _filename;
int _position;
Activity _parent;
BanjiChapter _chap;
FileUtilities _fUtils;
ViewPager _pager;
public AwesomeFragment () {}
public AwesomeFragment (string path,
string filename,
int position,
Activity parent,
FileUtilities FUtils,
ViewPager Pager)
{
_path = path;
_filename = filename;
_position = position;
_parent = parent;
_fUtils = FUtils;
_pager = Pager;
}
public override View OnCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
/* --- Create the view --- */
var view = inflater.Inflate (Resource.Layout.BookWebView, container, false);
//return the chapter
_chap = _fUtils.ReturnChapterDetails(_filename, _position);
web_view = view.FindViewById<WebView> (Resource.Id.webview);
web_view.SetWebViewClient(new BanjiWebClient(_position,_path,_parent, _pager, _chap.Name ));
web_view.SetBackgroundColor(Color.Transparent);
web_view.Settings.JavaScriptEnabled = true;
web_view.Tag = 300 + _position;
switch(Resources.DisplayMetrics.DensityDpi){
case Android.Util.DisplayMetricsDensity.Medium:
{
web_view.SetLayerType (LayerType.Software, null);
break;
}
case Android.Util.DisplayMetricsDensity.High:
{
web_view.SetLayerType (LayerType.Hardware, null);
break;
}
case Android.Util.DisplayMetricsDensity.Xhigh:
{
web_view.SetLayerType (LayerType.Hardware, null);
break;
}
}
if (_chap.Background == null) {
view.SetBackgroundColor (Color.White);
} else {
view.SetBackgroundDrawable (new BitmapDrawable (BitmapFactory.DecodeByteArray (_chap.Background, 0, _chap.Background.Length)));
}
if (_position == 0) {
web_view.LoadUrl ("file://" + _path + "/" + _chap.Name);
}
return view;
}
public BChapter GetCurrentBChapter()
{
return _chap;
}
}
EDIT:
BookView.axml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffececec">
<!-- The main content view -->
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/mainView">
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/bookView" />
<ImageButton
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="left|center"
android:background="@null"
android:id="@+id/menuButton"
/>
</FrameLayout>
<!-- The navigation drawer -->
<LinearLayout
android:id="@+id/left_menu"
android:layout_width="250dp"
android:layout_height="match_parent"
android:choiceMode="singleChoice"
android:layout_gravity="start"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:background="#111">
<Button
android:id="@+id/backStep"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
style="@style/button_text"
android:background="#ff000000"
android:fitsSystemWindows="false" />
<Space
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/screllArea">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/ThumbLayout" />
</ScrollView>
</LinearLayout>
</android.support.v4.widget.DrawerLayout>
BookWebView
<?xml version="1.0" encoding="utf-8"?>
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
