让我们看下面的源代码。这里的片段名称是DirectoryOfEbooks。
在后台任务完成后,我将用当前片段替换框架。这样片段就会刷新并重新加载其数据。
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import com.github.mikephil.charting.data.LineRadarDataSet;
import java.util.ArrayList;
import java.util.List;
public class DirectoryOfEbooks extends Fragment {
RecyclerView recyclerView;
branchesAdapter adapter;
LinearLayoutManager linearLayoutManager;
Cursor c;
FragmentTransaction fragmentTransaction;
SQLiteDatabase db;
List<branch_sync> directoryarraylist;
public DirectoryOfEbooks() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_directory_of_ebooks, container, false);
directoryarraylist = new ArrayList<>();
db = getActivity().openOrCreateDatabase("notify", android.content.Context.MODE_PRIVATE, null);
c = db.rawQuery("select * FROM branch; ", null);
if (c.getCount() != 0) {
c.moveToFirst();
while (true) {
String branch = c.getString(c.getColumnIndex("branch"));
branch_sync branchSync = new branch_sync(branch);
directoryarraylist.add(branchSync);
if (c.isLast())
break;
else
c.moveToNext();
}
recyclerView = (RecyclerView) view.findViewById(R.id.directoryOfEbooks);
adapter = new branchesAdapter(directoryarraylist, this.getContext());
adapter.setHasStableIds(true);
recyclerView.setItemAnimator(new DefaultItemAnimator());
System.out.println("ebooks");
recyclerView.setHasFixedSize(true);
linearLayoutManager = new LinearLayoutManager(this.getContext());
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setAdapter(adapter);
System.out.println(adapter.getItemCount()+"adpater count");
}
return view;
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
public void onPrepareOptionsMenu(Menu menu) {
MenuInflater inflater = getActivity().getMenuInflater();
inflater.inflate(R.menu.refresh, menu);
MenuItem menuItem = menu.findItem(R.id.refresh1);
menuItem.setVisible(true);
}
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.refresh1) {
new AlertDialog.Builder(getContext()).setMessage("Refresh takes more than a Minute").setPositiveButton("Refresh Now", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
new refreshebooks().execute();
}
}).setNegativeButton("Refresh Later", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
}
}).setCancelable(false).show();
}
return super.onOptionsItemSelected(item);
}
public class refreshebooks extends AsyncTask<String,String,String>{
ProgressDialog progressDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog=new ProgressDialog(getContext());
progressDialog.setMessage("\tRefreshing Ebooks .....");
progressDialog.setCancelable(false);
progressDialog.show();
}
@Override
protected String doInBackground(String... params) {
Ebooksync syncEbooks=new Ebooksync();
String status=syncEbooks.syncdata(getContext());
return status;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if(s.equals("error")){
progressDialog.dismiss();
Toast.makeText(getContext(),"Refresh Failed",Toast.LENGTH_SHORT).show();
}
else{
fragmentTransaction = getActivity().getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.mainframe, new DirectoryOfEbooks());
fragmentTransaction.commit();
progressDialog.dismiss();
adapter.notifyDataSetChanged();
Toast.makeText(getContext(),"Refresh Successfull",Toast.LENGTH_SHORT).show();
}
}
}
}
TextView
的已知属性,例如文本大小,不是您需要调用invalidate()
的事情;当属性更改时,框架会为您执行此操作。也许展示一下您正在更新文本属性的代码;问题更可能出在那里。您唯一需要手动invalidate()
视图的时间是如果您创建了Android不知道的自定义属性。 - devunwiredsetRawTextSize()
(第2406行)...在更新属性后会调用什么?https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/java/android/widget/TextView.java 此外,invalidate()
不会强制视图自适应,而是requestLayout()
实现此功能。 - devunwired