android - 自定义 Gridview getitemid() 不返回正确的 row_id

Question

我在 ScrollView 中使用自定义 GridView。我知道这不是正确的方法。我没有任何其他方法来完成我的应用程序布局。

我试图在 GridView 中获取数据库的 item id == row_id 但它没有返回正确的 id。它没有提供 row_id，而是提供了与数据库 row_id 不匹配的项目的位置 ID我知道Adapter中的position id是row_id，不知道为什么id和数据库不匹配。

这是我在布局上使用的 GridView

 <info.androidhive.slidingmenu.MyGridView
    android:id="@+id/gridview11"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="278dp"
    android:numColumns="2"
    android:verticalSpacing="2dp"
    android:horizontalSpacing="0dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
    android:isScrollContainer="false"
    android:focusable="false"
    android:focusableInTouchMode="false"
 />

这是自定义 MyGridview 代码。我从 Github

使用了这个

import android.content.Context;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.GridView;

/**
 * ScrollViewの中のGridViewでも高さを可変にする<br>
 * https://stackoverflow.com/questions/8481844/gridview-height-gets-cut
 */
public class MyGridView extends GridView
{

    boolean expanded = false;

    public MyGridView(Context context)
    {
        super(context);
    }

    public MyGridView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
    }

    public MyGridView(Context context, AttributeSet attrs,
                                    int defStyle)
    {
        super(context, attrs, defStyle);
    }

    public boolean isExpanded()
    {
        return expanded;
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        // HACK! TAKE THAT ANDROID!
        if (isExpanded())
        {
            // Calculate entire height by providing a very large height hint.
            // View.MEASURED_SIZE_MASK represents the largest height possible.
            int expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK,
                    MeasureSpec.AT_MOST);
            super.onMeasure(widthMeasureSpec, expandSpec);

            ViewGroup.LayoutParams params = getLayoutParams();
            params.height = getMeasuredHeight();
        }
        else
        {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    public void setExpanded(boolean expanded)
    {
        this.expanded = expanded;
    }
}

最后这里是onlcikListener代码，不能正常工作

 try {
            // OnClick

            best_product_gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                    //get position index of item here.

                    String indexid = String.valueOf(position);
                    Log.d("Index of Selected ", indexid);

                    // calling function
                     globalVariable.product_id =  position;
                    ((MainActivity)getActivity()).product();

                }
            });

    } 
    catch (Exception e)
    {
      Log.d("Error BestPrduct View","" + e);
    }

这是适配器类

package info.androidhive.slidingmenu.AdpaterClass;

import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;

import com.squareup.picasso.Picasso;

import java.util.ArrayList;
import java.util.HashMap;

import info.androidhive.slidingmenu.R;
import info.androidhive.slidingmenu.library.Function_List;
import info.androidhive.slidingmenu.library.Global_JsonTags;
import info.androidhive.slidingmenu.library.Global_Variable;

/**
 * Created by clint19 on 1/21/2016.
 */
public class Best_Product extends BaseAdapter {
    View gridView;
    private Context context;
  /*  private DisplayImageOptions options;*/

    private LayoutInflater inflater;

    // josn vaules from json file library
    Global_JsonTags jsontags = new Global_JsonTags();
    Function_List lib_function =  new Function_List();
    Global_Variable globalVariable = new Global_Variable();
    private ArrayList<HashMap<String, String>> MyArr = new ArrayList<HashMap<String, String>>();

    public Best_Product(Context c,ArrayList<HashMap<String, String>> json_value) {
        // TODO Auto-generated method stub
        context = c;
        MyArr = json_value;

    }

    public int getCount() {
        // TODO Auto-generated method stub
        Log.d("size of item", "" + MyArr.size());
        return MyArr.size();
    }

    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;

    }


    public View getView(int position, View convertView, ViewGroup parent) {
        final ViewHolder holder;
        View view = convertView;
        TextView product_name;
        TextView product_price;
        ImageView imageView;
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View gridView;
        if (view == null) {
            view = new View(context);
            view = inflater.inflate(R.layout.home_best_collection, parent, false);
            holder = new ViewHolder();
            assert view != null;
            imageView = (ImageView) view.findViewById(R.id.imageView26);
           // holder.imageView = (ImageView) view.findViewById(R.id.imageView26);
            holder.progressBar = (ProgressBar) view.findViewById(R.id.progress);
            product_name = (TextView) view.findViewById(R.id.textView21);
            product_price = (TextView) view.findViewById(R.id.textView23);

            String name = MyArr.get(position).get("product_name");
            int namelength = name.length();
            if(namelength >= 33)
            {
                product_name.setText(MyArr.get(position).get("product_name").substring(0, 29) + "...");
            }
            else{product_name.setText(MyArr.get(position).get("product_name"));}
            product_price.setText(MyArr.get(position).get("product_price"));
            String product_status = MyArr.get(position).get("product_status");

            if(product_status.equals("false"))
            {

                Button add_to_cart = (Button) view.findViewById(R.id.add_to_cart1);
                add_to_cart.setVisibility(View.GONE);
                View background_height = (View) view.findViewById(R.id.bestproduct1);
            }
            else
            {
                Button add_to_cart = (Button) view.findViewById(R.id.add_to_cart1);
                add_to_cart.setVisibility(View.VISIBLE);
            }
            Log.d("setting up text", "setting up text");

            Picasso.with(context)
                    .load(MyArr.get(position).get("product_image"))
                    .placeholder(R.drawable.ic_stub) // optional
                    .error(R.drawable.ic_error)         // optional
                    .into(imageView);

            //view.setTag(holder);
        } else {
            holder = (ViewHolder) view.getTag();
        }


        return view;
    }


    static class ViewHolder {
        ImageView imageView;
        ProgressBar progressBar;
    }

}

我想从 2 小时开始获取 ID，但没有成功。我关注了这些问题 How to add gridview setOnItemClickListener和 Android gridview OnItemClickListener还有这个Get ID of View in GridView 可能更多。

谁能告诉我哪里出了问题。

Answer 1

i m trying to get item id == row_id of database of GridView but it does not right id

那是因为您没有在您的 Adapter 中正确覆盖 getItemId。假设您为适配器提供的数据集由 bean 类组成，您需要做的是覆盖 getItemId(int position)，它返回一个 long，并让它返回正确的 ID。例如

@Override
public long getItemId(int position) {
   return getItem(position).getId();
}

正确的值作为最后一个参数 long id 在 onItemClick 中传递。

如果您要对 CursorAdapter(或其具体实现之一)进行子类化，并且您应该这样做，因为您有一个基于游标的解决方案，你不需要覆盖它。 CursorAdapter 已经返回光标所在位置的 _id 列的值。

编辑

@Override
public long getItemId(int position) {
   HashMap<String, String> mapAtPostion = MyArr.get(position);
   return Long.valueOf(mapAtPostion.get("product_id"));
}