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我一直在尝试了解 android 中的列表和其他东西。按名称、日期、类型和大小列出。请帮帮我..我在这里显示我的代码..它在列表视图中显示内容。

package com.android.sam;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener ;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ListActivity;

import android.content.Context;
import android.content.DialogInterface;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class SamActivity  extends ListActivity {

private List<String> item = null;

private List<String> path = null;

private String root="/";

private TextView myPath;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
    myPath = (TextView)findViewById(R.id.path);
getDir(root);
}
private void getDir(String dirPath)

{

 myPath.setText("Location: " + dirPath);



 item = new ArrayList<String>();

 path = new ArrayList<String>();



 File f = new File(dirPath);

 File[] files = f.listFiles();



 if(!dirPath.equals(root))

 {



  item.add(root);

  path.add(root);



  item.add("../");

  path.add(f.getParent());



  }



  for(int i=0; i < files.length; i++)

  {

   File file = files[i];

   path.add(file.getPath());

   if(file.isDirectory())

    item.add(file.getName() + "/");

   else

    item.add(file.getName());

  }



  ArrayAdapter<String> fileList =

   new ArrayAdapter<String>(this, R.layout.row, item);

   setListAdapter(fileList);

  }
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
File file = new File(path.get(position));
if (file.isDirectory())

 {

 if(file.canRead())

 getDir(path.get(position));

 else

{

 new AlertDialog.Builder(this)

.setIcon(R.drawable.ic_launcher)

.setTitle("[" + file.getName() + "] folder can't be read!")

.setPositiveButton("OK", 

  new DialogInterface.OnClickListener() {

 public void onClick(DialogInterface dialog, int which) {

    // TODO Auto-generated method stub

   }

  }).show();

  }

  }

 else

{

  new AlertDialog.Builder(this)

.setIcon(R.drawable.alert)

.setTitle("[" + file.getName() + "] ")

.setPositiveButton("OK", 

  new DialogInterface.OnClickListener() {

  public void onClick(DialogInterface dialog, int which) {

    // TODO Auto-generated method stub

   }

  }).show();

  }

   }

  }

在我的布局中,我添加了一个图像按钮,它应该显示排序选项并提前对列表进行排序谢谢这是我添加的 `sorting= (Button) findViewById(R.id.button2); 最终上下文 context1=this; 排序.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {

          if (v == findViewById(R.id.button2)) {

                 final CharSequence[] items = {"name", "date", "size", "type", "none"};

                 AlertDialog.Builder builder = new AlertDialog.Builder(context1);

                 builder.setTitle("Sort by");

                 builder.setSingleChoiceItems(items, -1, new                                    DialogInterface.OnClickListener       ()       {
                     // Click listener
                     public void onClick(DialogInterface dialog, int item) {
                         Toast.makeText(getApplicationContext(), items[item],            Toast.LENGTH_SHORT).show();
                         //If the Cheese item is chosen close the dialog box
                         if(items[item]=="none")
                             dialog.dismiss();
                     }
                 });
                 AlertDialog alert = builder.create();
                 //display dialog box
                 alert.show();
             }
      }
      });  
4

1 回答 1

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1-您是否只想对 String 对象的 ArrayList 进行排序,因为 ArrayList 可以使用 Collections.sort(item);

2-如果您有对象类型的 ArrayList,则需要为此创建比较器。

http://www.developer.com/java/other/article.php/858411/Data-Structures-in-Java-Part-9-The-Comparator-Interface-Part-1.htm

java-sorting-comarator-vs-comparable

于 2012-06-07T11:25:06.263 回答