Android Lab Test : Reading the foot file list (english)
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The document provides a tutorial on how to use the Android file manager to list root directories and files. It includes code snippets for retrieving the application directory, absolute paths, and checking directory entries. Additionally, it introduces basic building blocks of an Android application interface using XML layout and Java code.
![The list of the root directories
• To get the list of directories and files at the root, use the
method listRoots().
File[] files = File.listRoots();](https://image.slidesharecdn.com/androidlabtest-filelistrootseng-150226063939-conversion-gate01/85/Android-Lab-Test-Reading-the-foot-file-list-english-4-320.jpg)
![File Main.java
public class Main extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
EditText et_output = (EditText)findViewById (R.id.et_output);
File file = this.getFilesDir();
String text = "Local storage : " + file.getAbsolutePath();
File[] files = File.listRoots();
for (int i = 0; i < files.length; i++){
String filename = files[i].getAbsolutePath();
filename.replaceAll (new String(new byte[]{0}), "");
File rootFile = new File (filename);
if (file.isDirectory()) {
for (int j = 0; j < rootFile.listFiles().length; j++){
text += rootFile.listFiles() [j].getAbsolutePath() + "rn";
}
}
}
et_output.setText (text);
}
}](https://image.slidesharecdn.com/androidlabtest-filelistrootseng-150226063939-conversion-gate01/85/Android-Lab-Test-Reading-the-foot-file-list-english-7-320.jpg)
Android Lab Test : Reading the foot file list (english)
- 1. Develop on Android Android Lab Test www.AndroidLabTest.com Youku By Bruno Delb www.weibo.com/brunodelb i.youku.com/brunodelb | www.weibo.com/brunodelb | blog.delb.cn http://i.youku.com/brunoparis Weibo Officialsite Lesson : The list of root directories
- 2. The list of the root directories • In this lesson, you will learn to use the file manager to list the list of root files. • For this, you will use File and listFiles.
- 3. The list of the root directories • In order to know the path to the application directory, use the method getFilesDir(). File file = this.getFilesDir(); • In order to know the absolute path to a directory, use the method getAbsolutePath() : String text = "Local storage : " + file.getAbsolutePath();
- 4. The list of the root directories • To get the list of directories and files at the root, use the method listRoots(). File[] files = File.listRoots();
- 5. The list of the root directories • To know if an entry of a directory is a directory, use the method isDirectory() : if (file.isDirectory()) { } • To get he list of the files and directories of a directory, use the method listFiles() : rootFile.listFiles()
- 6. Layout main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <EditText android:id="@+id/et_output" android:layout_width="match_parent" android:layout_height="match_parent" android:ems="10" > </EditText> </LinearLayout>
- 7. File Main.java public class Main extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); EditText et_output = (EditText)findViewById (R.id.et_output); File file = this.getFilesDir(); String text = "Local storage : " + file.getAbsolutePath(); File[] files = File.listRoots(); for (int i = 0; i < files.length; i++){ String filename = files[i].getAbsolutePath(); filename.replaceAll (new String(new byte[]{0}), ""); File rootFile = new File (filename); if (file.isDirectory()) { for (int j = 0; j < rootFile.listFiles().length; j++){ text += rootFile.listFiles() [j].getAbsolutePath() + "rn"; } } } et_output.setText (text); } }
- 8. Test on your mobile File_ListRoots
- 9. Follow me on my channel PengYooTV … On my Youku channel http://i.youku.com/brunoparis Who am I ? Bruno Delb (www.delb.cn), Author of the first french book of development of Java mobile application (2002), Consultant, project manager and developer of social & mobile applications, let’s talk about your needs ... And on Weibo : http://www.weibo.com/brunodelb