Question

我已经编写了在android studio上显示ExpandableListView的代码。这是ExplandableListView的代码：

public class Recipes extends AppCompatActivity implementsView.OnClickListener           {
ExpandableListView exp;
EditText t;
Button b;


HashMap<String, List<String>> Movies_category;
List<String> Movies_list;
ExpandableListView Exp_list;
MoviesAdapter adapter;

protected void onCreate(Bundle savedInstanceState) {
    setTheme(R.style.NoActionBar);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_recipes);
    t = (EditText) findViewById(R.id.t);
    b = (Button) findViewById(R.id.b);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_recipes);
    Exp_list = (ExpandableListView) findViewById(R.id.exp_list);
    Movies_category = DataProvider.getInfo();
    Movies_list = new ArrayList<String>(Movies_category.keySet());
    adapter = new MoviesAdapter(this, Movies_category, Movies_list);
    Exp_list.setAdapter(adapter);
    t.setOnClickListener(this);
    b.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    startActivity(new Intent(this, Choose.class));
    }
}

这是执行操作的方法：

public class RecipeAda extends BaseExpandableListAdapter{
private Context ctx;
private HashMap<String, List<String>> recipes;
private List<String> ingr;
public RecipeAda(Context ctx,HashMap<String, List<String>>recipes, List<String> ingr)
{
     this.ctx=ctx;
    this.recipes=recipes;
    this.ingr=ingr;
}

@Override
public int getGroupCount() {
    return recipes.size();
}

@Override
public int getChildrenCount(int groupPosition) {
    return recipes.get(ingr.get(groupPosition)).size();
}


@Override
public Object getGroup(int groupPosition) {
    return recipes.get(groupPosition);
}

@Override
public Object getChild(int parent, int child) {
    return recipes.get(ingr.get(parent)).get(child);
}


@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}


@Override
public long getChildId(int parent, int child) {
    return child;
}

@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(int parent, boolean isExpanded, View convertView, ViewGroup parentview) {
    String grptit= (String) getGroup(parent);
    if (convertView==null)
    {
        LayoutInflater inf= (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView=inf.inflate(R.layout.parent_layout,parentview,false);
    }
    TextView pa= (TextView) convertView.findViewById(R.id.textView4);
    pa.setTypeface(null, Typeface.BOLD);
    pa.setText(grptit);
    return convertView;
}


@Override
public View getChildView(int parent, int child, boolean lastChild, View convertView, ViewGroup parentview) {
    String childtitle= (String) getChild(parent,child);
    if (convertView==null)
    {
        LayoutInflater inf= (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView=inf.inflate(R.layout.child_layout,parentview,false);
    }
    TextView ch= (TextView) convertView.findViewById(exp_list);
    ch.setText(childtitle);
    return convertView;
}

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return false;
}}

它在＆＃34; groupPosition＆＃34;显示警告。在函数定义中：

@Override
public Object getGroup(int groupPosition) {
    return recipes.get(groupPosition);
}

当它悬停在它上面时，HashMap<String, List<String>> may not contain objects of type 'integer'说我该如何纠正？
另外，如何接受用户的内容（字符串）并保存在数据库中？

Answer 1

要创建HashMap，它需要两件事：一个键和一个类型。要获取类型（在您的情况下为List），您需要传递一个键（在您的情况下为String）。这意味着如果您想使用当前代码.get，则必须传递一个字符串。如果要使用整数，只需将hashmap更改为：

private HashMap<Integer, List<String>> recipes;

或者，如果您想使用带数字的字符串

，请Integer.toString(id);

另外，我如何接受用户的内容

取决于您的意思＆＃34;接受内容＆＃34;。如果您只想将一个String传递给hashmap，那么您可以执行.put(id, "some string");

并保存？

External data，Internal data，
SQL，
SharedPrefs

HashMap <string，list <string =“”>＆gt;可能不包含类型＆＃39;整数＆＃39;

1 个答案: