单击Spinner
将新数据添加到RecyclerView
而不删除旧数据的项目。刷新ArrayList以使用单击微调器向RecyclerView显示新数据项目
一样,我有一个微调two
项目:Appliances
和Accessories
。
默认情况下,我显示Appliances
数据为RecyclerView,但每当我做tap
上配件 - 这正显示出Accessories data
到RecyclerView,但below Appliances data
,而我期待只有Accessories
数据到RecyclerView
MainActivity.java:
public class MainActivity extends AppCompatActivity {
.....
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu_screen);
.........
stringList = new ArrayList<String>();
stringList.add("Appliances");
stringList.add("Accessories");
ArrayAdapter<String> stringArrayAdapter = new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_dropdown_item_1line,
stringList);
spinnerMenu.setAdapter(stringArrayAdapter);
......
initializeAdapter();
.....
spinnerMenu.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
switch (position) {
case 0:
presenter.loadAppliances();
break;
case 1:
presenter.loadAccessories();
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
.......
}
public void initializeAdapter() {
categoryAdapter = new CategoryAdapter(this, new ArrayList<Category>());
mRecyclerView.setAdapter(categoryAdapter);
}
public void addMenu(List<Category> posts) {
categoryAdapter.addAllData(posts);
categoryAdapter.notifyDataSetChanged();
}
}
CategoryAdapter.java:
@Override
public int getItemCount() {
return posts.size();
}
public void setPosts(List<Categories> posts) {
this.posts = posts;
}
public void clearData() {
posts.clear();
}
public void addAllData(List<Categories> posts) {
this.posts.addAll(posts);
}
}
为什么它被低估?我不认为这是我发布的错误。 – Sophie
嘿在调用'menuPresenter.loadAppliances();'之后清空你的列表'并且在调用'notifyDataSetChanged()' –
尝试过但得到空指针异常 – Sophie