我正在尝试制作一个相对简单的文件系统浏览器，它显示目录并允许您选择它们。我有一个列表片段，它使用自定义适配器将目录显示为列表。我为列表中的每个条目创建了一个clickListener。我需要得到它，以便在单击列表条目时，整个列表视图刷新。因为这个单击侦听器是在我的适配器中定义的，它如何以某种方式向列表片段发出信号，以告诉它刷新适配器使用的数据。非常感谢。
这是我的代码：
PickerFragment.java：
package com.grid.picker;
import android.content.Intent;
import android.os.Bundle;
//import android.support.v4.app.Fragment;
import android.os.Environment;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.List;
import static android.content.Intent.getIntent;
public class PickerFragment extends ListFragment
{
private String currentFilesystemPath = ""; // This path does not include the root path
private int numberOfFolders = 0;
private List<Folder> folders = new ArrayList<Folder>();
public PickerFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
private void tempPopulate()
{
folders.add(new Folder("TestFolder", "/test/path"));
}
private void populateFolders()
{
// Create a new File at the current path
File currentFolder = new File(Environment.getExternalStorageDirectory().getPath()+currentFilesystemPath);
Utility.debugOutput("populateFolders() currentFolder: " +currentFolder);
// Lets get the list of folders
String[] directories = currentFolder.list(new FilenameFilter() {
@Override
public boolean accept(File current, String name) {
return new File(current, name).isDirectory();
}
});
// Build up the list of folders with folder objects
for(int i=0; i<directories.length;i++)
{
//Utility.debugOutput("Folder:" +directories[i].toString());
folders.add(new Folder(directories[i].toString(), currentFolder.getPath()+directories[i].toString()));
}
}
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
// Temporary folder population
//tempPopulate();
populateFolders();
/*
// Set an adapter for this list fragment to use
setListAdapter(new ArrayAdapter<Folder>(getActivity(),
android.R.layout.simple_list_item_activated_1, folders));
*/
// We want to use our custom adapter. We pass in this activity, the layout to use, and an array of folders
// We give it a new Folder object just so it knows what type of objects are in the array...??
FolderAdapter adapter = new FolderAdapter(this.getActivity(), R.layout.listview_item_row, folders.toArray(new Folder[0]));
// Use our custom adapter for the list
setListAdapter(adapter);
}
}
FolderAdapter.java：
package com.grid.picker;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class FolderAdapter extends ArrayAdapter<Folder>
{
Folder[] folders = null;
Context context;
int layoutResourceId;
// Constructor
// Param 1: Reference of the activity
// Param 2: The resource id of the layout file we want to use for displaying each ListView item
public FolderAdapter(Context context, int layoutResourceId, Folder[] data)
{
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.folders = data;
}
// This is a function that the click listener can call to start the list update process
public void updateList(String name)
{
Utility.debugOutput("updateList() rx: " +name);
this.notifyDataSetChanged();
}
// Presumably getView is called for every row in the list ?
// position is the index of the list item in the list
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
// Create a new view to play with
View row = convertView;
final int rowID = position;
FolderHolder holder = null;
if(row == null)
{
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
// Inflate (parse) the layout XML
row = inflater.inflate(layoutResourceId, parent, false);
//Instantiate a new static object for folder icons (static for speed (caching)
holder = new FolderHolder();
holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);
row.setTag(holder);
// Set clickListener
row.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
Utility.debugOutput("Row ID clicked: " +rowID);
Utility.debugOutput("Folder array:" +folders[rowID].folderName);
updateList(folders[rowID].folderName);
//Toast.makeText(context,"you clicked item: "+rowID, Toast.LENGTH_LONG.show();
//code you want to execute on click of list item...
}
});
}
else
{
holder = (FolderHolder)row.getTag();
}
Folder folder = folders[position];
holder.txtTitle.setText(folder.folderName);
holder.txtTitle.setText(folder.folderName);
holder.imgIcon.setImageResource(folder.icon);
/*
// Add click listener to the view
View.OnClickListener clickListener = new View.OnClickListener() {
public void onClick(View v) {
Utility.debugOutput("Something clicked???!");
// This call requires API level 15 minimum...
v.callOnClick();
}
}; */
//row.setOnClickListener(clickListener);
return row;
}
// This class will be used as a cache for the folder images
static class FolderHolder
{
ImageView imgIcon;
TextView txtTitle;
}
}
Folder.java：
package com.grid.picker;
public class Folder
{
// Each instance of this class will be an entry in the folder list
public String folderName;
public String fullPath;
public boolean hasChildren = false; // False by default
public static final int icon = R.drawable.folder;
// Constructor
public Folder(String newName, String newFullPath)
{
folderName = newName;
fullPath = newFullPath;
}
}
listview_item_row.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp">
<ImageView android:id="@+id/imgIcon"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="true"
android:layout_marginRight="15dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp" />
<TextView android:id="@+id/txtTitle"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="true"
android:textStyle="bold"
android:textSize="22dp"
android:textColor="#000000"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp" />
</LinearLayout>
最终我需要在列表中显示的每个文件夹上放置一个复选框，但是现在我需要获取它，以便可以单击列表中显示的文件夹来刷新显示并更新列表。非常感谢。
答案 0 :(得分：1)
在点击侦听器上使用此功能
// Set clickListener
row.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
Utility.debugOutput("Row ID clicked: " +rowID);
Utility.debugOutput("Folder array:" +folders[rowID].folderName);
notifyDataSetInvalidated();
}
});