爲什麼我無法在android中查看我的Listview？

Question

我試圖從我的片段傳遞一些信息到我的適配器來顯示一個ListView，它確實通過，但ListView在完成加載後不顯示任何東西。 我在下面附加了我的CustomAdapter類。

package com.example.rama.hello.Adapters;

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.BaseAdapter; 
import android.widget.ImageView; 
import android.widget.TextView; 
import com.example.rama.hello.Bean.RowItem; 
import com.example.rama.hello.R; 

import java.io.File; 
import java.util.ArrayList; 
import java.util.List; 

/** 
* Created by RAMA on 10/25/2016. 
*/ 
public class CustomAdapter extends ArrayAdapter<RowItem> { 

    Context mcontext; 
    ArrayList<RowItem> rowItem = new ArrayList<RowItem>(); 
    private RowItem row; 
    RowItem data; 


    public CustomAdapter(Context context, int resourceId, 
           ArrayList<RowItem> items) { 
     super(context, resourceId, items); 
     this.mcontext = context; 
    } 

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


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

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) 
    { 
     if (convertView == null) 
     { 
      LayoutInflater mInflater = (LayoutInflater) mcontext 
        .getSystemService(Activity.LAYOUT_INFLATER_SERVICE); 
      convertView = mInflater.inflate(R.layout.list_item,parent,false); 
     } 

     ImageView imgIcon = (ImageView) convertView.findViewById(R.id.icon); 
     TextView txtTitle = (TextView) convertView.findViewById(R.id.title); 
     TextView txtSubTitle = (TextView) convertView.findViewById(R.id.sub_title); 
     TextView txtRightTitle = (TextView) convertView.findViewById(R.id.right_title); 

     RowItem row_pos = getItem(position); 

     // setting the image resource and title,subtitle,Righttitle 
     File imgFile = new File(row_pos.getIcon()); 

     if(imgFile.exists()){ 

      Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath()); 
      imgIcon.setImageBitmap(myBitmap); 
     } 


     if(row_pos.getTitle() == " ") 
     txtTitle.setText(row_pos.getPhone_number()); 
     else 
     txtTitle.setText(row_pos.getTitle()); 

     txtSubTitle.setText(row_pos.getSub_title()); 
     txtRightTitle.setText(row_pos.getRight_title()); 

     return convertView; 
    } 
} 

Answer 1

在ArrayAdapter你並不需要得到您的項目列表的引用（在RowItem你的情況列表），這是不是對ArrayAdapter製成，所有你需要的是覆蓋getView和ArrayAdapter將在內部爲您處理清單，這裏是它應該是這樣的：

public class CustomAdapter extends ArrayAdapter<RowItem> { 


    public CustomAdapter(Context context, int resourceId, 
         ArrayList<RowItem> items) { 
     super(context, resourceId, items); 
    } 


    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     if (convertView == null) { 
     LayoutInflater mInflater = LayoutInflater.from(parent.getContext()); 
     convertView = mInflater.inflate(R.layout.list_item, parent, false); 
     } 

     ImageView imgIcon = (ImageView) convertView.findViewById(R.id.icon); 
     TextView txtTitle = (TextView) convertView.findViewById(R.id.title); 
     TextView txtSubTitle = (TextView) convertView.findViewById(R.id.sub_title); 
     TextView txtRightTitle = (TextView) convertView.findViewById(R.id.right_title); 

     RowItem row_pos = getItem(position); 

     // setting the image resource and title,subtitle,Righttitle 
     File imgFile = new File(row_pos.getIcon()); 

     if (imgFile.exists()) { 

     Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath()); 
     imgIcon.setImageBitmap(myBitmap); 
     } 


     if (row_pos.getTitle() == " ") 
     txtTitle.setText(row_pos.getPhone_number()); 
     else 
     txtTitle.setText(row_pos.getTitle()); 

     txtSubTitle.setText(row_pos.getSub_title()); 
     txtRightTitle.setText(row_pos.getRight_title()); 

     return convertView; 
    } 
    }