Android 适配器不工作

Question

我已关注 this tutorial for the creation of a custom adapter.This link is mentioned in the comments to this SO 问题。

给出代码如下：

MyMainView.xml

<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.context.GlobalSearch">

<AutoCompleteTextView
    android:id="@+id/globalSearch_editBrandData"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="16sp"
    android:hint="Enter Name"
    android:imeOptions="actionDone"
    android:singleLine="true"
/>

<ListView
    android:id="@+id/globalSearch_listResult"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_below="@+id/globalSearch_editBrandData"
    android:visibility="visible"
>
</ListView>

<TextView
    android:id="@+id/globalSearch_errorMessage"
    android:layout_below="@+id/globalSearch_editBrandData"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="Please enter the correct data"
    android:gravity="center"
    android:layout_marginBottom="100dp"
    android:visibility="gone"
/>

在每个元素的列表中，我想显示一个图像和一些文本。所以我编辑的 listview 字段定义为：

MyEdited.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:background="@drawable/rounded_corners"
    android:layout_marginLeft="2dp"
    android:layout_marginRight="2dp"
    android:elevation="1dp" >

    <ImageView
        android:id="@+id/globalSearch_imageView"
        android:layout_width="32dp"
        android:layout_height="32dp"
        android:layout_alignParentLeft="true"
        android:layout_marginTop="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        />

    <TextView
        android:id="@+id/globalSearch_textView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_toRightOf="@+id/globalSearch_imageView"
        android:text = "Puma"
        android:gravity="center"
        />
</RelativeLayout>

现在列表视图的适配器定义为：

GlobalSearchInformation.java

import android.util.Log;

public class GlobalSearchInformation {

private int drawableID;
private String textDetails;

public GlobalSearchInformation(int drawbaleID, String textDetails)
{
    super();
    this.drawableID = drawableID;
    this.textDetails = textDetails;
}

public void setTextDetails(String textDetails)
{
    this.textDetails = textDetails;
}

public String getTextDetails()
{
    return textDetails;
}

public void setDrawableID(int drawableID)
{
    this.drawableID = drawableID;
}

public int getDrawableID()
{
    return drawableID;
}

}

GlobalSearchAdapter.java

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

public class GlobalSearchAdapter extends BaseAdapter {
Context context;
protected List<GlobalSearchInformation> globalSearchList;
LayoutInflater layoutInflater;

public GlobalSearchAdapter(Context context, List<GlobalSearchInformation> globalSearchList)
{
    this.globalSearchList = globalSearchList;
    this.layoutInflater = LayoutInflater.from(context);
    this.context = context;
}

@Override
public int getCount() {
    return globalSearchList.size();
}

@Override
public Object getItem(int position) {
    return globalSearchList.get(position);
}

@Override
public long getItemId(int position) {
    return globalSearchList.get(position).getDrawableID();
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if(convertView == null)
    {
        holder = new ViewHolder();
        convertView = this.layoutInflater.inflate(R.layout.globalsearch_listview, parent, false);
        holder.globalsearchadapter_text = (TextView) convertView.findViewById(R.id.globalSearch_textView);
        holder.globalsearchadapter_image = (ImageView) convertView.findViewById(R.id.globalSearch_imageView);

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

    GlobalSearchInformation gsi = globalSearchList.get(position);
    holder.globalsearchadapter_image.setImageResource(gsi.getDrawableID());
    holder.globalsearchadapter_text.setText(gsi.getTextDetails());
    return convertView;
}

private class ViewHolder
{
    ImageView globalsearchadapter_image;
    TextView globalsearchadapter_text;
}
}

GlobalSearch.java

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

import APP.infrastructure.models.Merchant;

import java.util.ArrayList;
import java.util.List;


public class GlobalSearch extends ActionBarActivity {



ListView listViewGlobal;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_global_search);

    final AutoCompleteTextView actSearch = (AutoCompleteTextView) findViewById(R.id.globalSearch_editBrandSearch);
    final ListView lvSearch = (ListView) findViewById(R.id.globalSearch_listResult);
    final TextView tvSearch = (TextView) findViewById(R.id.globalSearch_errorMessage);

    List<Merchant> merchants = Merchant.findWithQuery(Merchant.class,"select * from MERCHANT");
    ArrayList <String> al = new ArrayList<String>();
    for(int i=0;i<merchants.size(); i++)
    {
        al.add(i, merchants.get(i).getName());
    }

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, al);
    actSearch.setAdapter(adapter);

    actSearch.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if(actionId == EditorInfo.IME_ACTION_DONE)
            {
                String mEdit = actSearch.getText().toString();
                List<Merchant> merchants = Merchant.findWithQuery(Merchant.class,"select * from MERCHANT where UPPER(NAME) LIKE \'"+mEdit.toUpperCase()+"%\'");

                if(merchants.size()==0)
                {
                    Log.d("debug", "Alert dialog: does not exist");
                    lvSearch.setVisibility(View.GONE);
                    tvSearch.setVisibility(View.VISIBLE);
                }
                else
                {
                    ArrayList <GlobalSearchInformation> arrayInformation = new ArrayList<GlobalSearchInformation>();
                    Log.d("global search", "merchant size != 0");
                    GlobalSearchInformation globalSearch_Page = new GlobalSearchInformation(R.drawable.image_id, merchants.get(0).getName());
                    GlobalSearchInformation globalSearch_Feed = new GlobalSearchInformation(R.drawable.image_id, "Posts by "+merchants.get(0).getName());
                    GlobalSearchInformation globalSearch_Store = new GlobalSearchInformation(R.drawable.image_id, merchants.get(0).getName()+" stores around you");
                    GlobalSearchInformation globalSearch_Alerts = new GlobalSearchInformation(R.drawable.image_id, merchants.get(0).getName()+" Events");
                    arrayInformation.add(globalSearch_Page);
                    arrayInformation.add(globalSearch_Feed);
                    arrayInformation.add(globalSearch_Store);
                    arrayInformation.add(globalSearch_Alerts);
                    GlobalSearchAdapter adapter = new GlobalSearchAdapter(getApplicationContext(), arrayInformation);
                    lvSearch.setAdapter(adapter);
                }
            }
            return false;
        }
    });

}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_global_search, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

}

所有这些都在编译并且运行没有错误但是在 autocomplete textview 中输入数据后查看 listview 时，正在检索数据库中的元素但是listview 仍然是空的。我哪里错了？

Answer 1

不要使用应用程序上下文来扩充列表视图。请改用 activity 上下文。

GlobalSearchAdapter 适配器 = new GlobalSearchAdapter(GlobalSearch.this, arrayInformation); lvSearch.setAdapter（适配器）；
不要在每次调用 onEditorAction 函数时都初始化适配器，而只是更新适配器中的数据并调用 notifyDataSetChanged().

globalSearch_textView 与 ListView 重叠，因此列表视图将不可见。更改文本视图的高度以包裹内容。

   <TextView

    android:id="@+id/globalSearch_textView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/globalSearch_imageView"
    android:gravity="center"
    android:text="Puma" />

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