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Android Listview删除项目并刷新_Android_Listview_Android Studio_Page Refresh_Uirefreshcontrol - Fatal编程技术网

Android Listview删除项目并刷新

Android Listview删除项目并刷新,android,listview,android-studio,page-refresh,uirefreshcontrol,Android,Listview,Android Studio,Page Refresh,Uirefreshcontrol,你好,我需要一些帮助。。。我写了这段代码,但我有点困惑,当我把书添加到我的fav it商店到fav时,当我点击fav列表中的un fav那里,书仍然在那个活动中,直到我重新打开fav活动时不关闭活动,书从那里被删除,我想添加代码,可以在我取消fav书时自行刷新。。。请帮帮我 public class Favrt extends AppCompatActivity implements AdapterView.OnItemClickListener { ListView viewF; Books_

你好,我需要一些帮助。。。我写了这段代码,但我有点困惑,当我把书添加到我的fav it商店到fav时,当我点击fav列表中的un fav那里,书仍然在那个活动中,直到我重新打开fav活动时不关闭活动,书从那里被删除,我想添加代码,可以在我取消fav书时自行刷新。。。请帮帮我

public class Favrt extends AppCompatActivity implements AdapterView.OnItemClickListener {
ListView viewF;
Books_Adapter fav_adapter;
String[] name, links, author;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_favrt);
    fetch_fav();
    fav_adapter = new Books_Adapter(this, name, links, author);
    viewF = (ListView) findViewById(R.id.favView);
    viewF.setAdapter(fav_adapter);
    viewF.setOnItemClickListener(this);
}
public void fetch_fav(){
    SQLiteDatabase database = openOrCreateDatabase("Pdf_books",MODE_PRIVATE,null);
    Cursor db_cursor = database.rawQuery("select * from favourite", null);
    name = new String[db_cursor.getCount()];
    links = new String[db_cursor.getCount()];
    author = new String[db_cursor.getCount()];
    int i =0;
    if (db_cursor.moveToLast()){
        do {
        name[i] = db_cursor.getString(db_cursor.getColumnIndex("name"));
        links[i] = db_cursor.getString(db_cursor.getColumnIndex("links"));
        author[i] = db_cursor.getString(db_cursor.getColumnIndex("author"));
        i++;
        }while (db_cursor.moveToPrevious());
    }

    database.close();
}



    @Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

    Intent web = new Intent(this, web_activity.class);
    web.putExtra("url", links[position]);
    startActivity(web);

}

@Override
public void onContentChanged() {
    super.onContentChanged();

    View empty = findViewById(R.id.empty);
    ListView list = (ListView) findViewById(R.id.favView);
    list.setEmptyView(empty);


}
公共类Favrt扩展AppCompativeActivity实现AdapterView.OnItemClickListener{
ListView视图f;
书籍适配器fav适配器;
字符串[]名称、链接、作者;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_favrt);
取法;
fav_adapter=新书_adapter(这个、名称、链接、作者);
viewF=(ListView)findViewById(R.id.favView);
viewF.setAdapter(fav_适配器);
viewF.setOnItemClickListener(此);
}
公共图书馆{
SQLiteDatabase=openOrCreateDatabase(“Pdf_books”,MODE_PRIVATE,null);
Cursor db_Cursor=database.rawQuery(“select*from favorite”,null);
name=新字符串[db_cursor.getCount()];
links=新字符串[db_cursor.getCount()];
author=新字符串[db_cursor.getCount()];
int i=0;
if(db_cursor.moveToLast()){
做{
name[i]=db_cursor.getString(db_cursor.getColumnIndex(“name”);
links[i]=db_cursor.getString(db_cursor.getColumnIndex(“links”);
author[i]=db_cursor.getString(db_cursor.getColumnIndex(“author”);
i++;
}而(db_cursor.moveToPrevious());
}
close()数据库;
}
@凌驾
public void onItemClick(AdapterView父对象、视图、整型位置、长id){
Intent web=新的Intent(这是web\u activity.class);
putExtra(“url”,链接[位置]);
星触觉(网络);
}
@凌驾
内容更改时的公共无效(){
super.onContentChanged();
视图为空=findViewById(R.id.empty);
ListView列表=(ListView)findViewById(R.id.favView);
list.setEmptyView(空);
}

}

更改列表项后(在本例中,当您的收藏夹更改时),请尝试
fav_适配器。notifyDataSetChanged()

您必须更新适配器。为此,
fav\u适配器。notifyDataSetChanged()
。这将对listview进行更改。 在活动中生成函数,您可以在其中执行诸如从数据库中删除和更新列表数据之类的操作