本文参考文献:《疯狂Android讲义 : 第2版 》
主布局文件:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/container"
android:background="@color/colorGray"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/path"
android:gravity="center_horizontal"
android:layout_alignParentTop="true"
/>
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/list"
android:divider="#000"
android:dividerHeight="1px"
android:layout_below="@+id/path"
/>
<Button
android:id="@+id/parent"
android:layout_width="38dp"
android:layout_height="34dp"
android:background="@drawable/back"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
列表项布局文件 line.xml 的内容:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:id="@+id/icon"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/file_name"
android:layout_marginStart="20dp"
/>
</LinearLayout>
主程序文件的内容如下:
package com.toby.personal.testlistview;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
final private static String TAG = "Toby_Test";
ListView listView;
TextView textView;
File currentParent;
File[] currentFiles;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.list);
textView = (TextView) findViewById(R.id.path);
Log.d(TAG, Environment.getExternalStorageDirectory().getPath());
File root = new File("/mnt/");
if (root.exists()) {
currentParent = root;
currentFiles = root.listFiles();
inflateListView(currentFiles);
}
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (currentFiles[position].isFile()) {
return;
}
File[] tmp = currentFiles[position].listFiles();
if (tmp == null || tmp.length == 0) {
Toast.makeText(MainActivity.this, "Current path is null.",
Toast.LENGTH_SHORT).show();
} else {
currentParent = currentFiles[position];
currentFiles = tmp;
inflateListView(currentFiles);
}
}
});
Button parent = (Button) findViewById(R.id.parent);
parent.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
if (!currentParent.getCanonicalPath().equals("/mnt/")) {
currentParent = currentParent.getParentFile();
currentFiles = currentParent.listFiles();
inflateListView(currentFiles);
}
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
private void inflateListView(File[] files) {
if (files == null || files.length <= 0) {
return;
}
List<Map<String, Object>> listItems = new ArrayList<>();
for (File file : files) {
Map<String, Object> listItem = new HashMap<>();
listItem.put("icon", file.isDirectory() ? R.drawable.folder : R.drawable.file);
listItem.put("fileName", file.getName());
listItems.add(listItem);
}
SimpleAdapter simpleAdapter = new SimpleAdapter(this, listItems, R.layout.line,
new String[]{"icon", "fileName"}, new int[]{R.id.icon, R.id.file_name});
listView.setAdapter(simpleAdapter);
try {
textView.setText(String.format("Current Path: %s", currentParent.getCanonicalPath()));
} catch (IOException e) {
e.printStackTrace();
}
}
}
运行效果: