如何读取SD卡上的android选定的文本文件 [英] How to read a selected text file from sdcard on android
本文介绍了如何读取SD卡上的android选定的文本文件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是新的android开发，我需要你的帮助。我被锁在那个对我的发展类似，但不那么帮助我的主题。 到目前为止，我创建一个让我从我的SD卡中的文件，并显示了我的话列表功能。 这是工作
i am new at android development and i need your help. I was locking at topics that are similar for my development but non of then help me. So far i create functions that gets me the files from my sdcard and shows me the list of then. That is working
这是在code获取SD卡上的路径：
this is the code for getting the paths on sdcard:
package com.seminarskirad;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.ListActivity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FilenameFilter;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
public class LoadActivity extends ListActivity{
private enum DISPLAYMODE{ ABSOLUTE, RELATIVE; }
private final DISPLAYMODE displayMode = DISPLAYMODE.ABSOLUTE;
private List<String> directoryEntries = new ArrayList<String>();
private File currentDirectory = new File("/");
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Browse(Environment.getExternalStorageDirectory());
}
private void upOneLevel(){
if(this.currentDirectory.getParent() != null)
this.Browse(this.currentDirectory.getParentFile());
}
private void Browse(final File aDirectory){
if (aDirectory.isDirectory()){
this.currentDirectory = aDirectory;
fill(aDirectory.listFiles());
}
}
private void fill(File[] files) {
this.directoryEntries.clear();
if(this.currentDirectory.getParent() != null)
this.directoryEntries.add("..");
switch(this.displayMode){
case ABSOLUTE:
for (File file : files){
this.directoryEntries.add(file.getPath());
}
break;
case RELATIVE: // On relative Mode, we have to add the current-path to the beginning
int currentPathStringLenght = this.currentDirectory.getAbsolutePath().length();
for (File file : files){
this.directoryEntries.add(file.getAbsolutePath().substring(currentPathStringLenght));
}
break;
}
ArrayAdapter<String> directoryList = new ArrayAdapter<String>(this, R.layout.load, this.directoryEntries);
this.setListAdapter(directoryList);
}
protected void onListItemClick(ListView l, View v, int position, long id) {
int selectionRowID = position;
String selectedFileString = this.directoryEntries.get(selectionRowID);
if(selectedFileString.equals("..")){
this.upOneLevel();
}else if(selectedFileString.equals()){ /// what to write here ???
this.readFile(); ///what to write here???
} else {
File clickedFile = null;
switch(this.displayMode){
case RELATIVE:
clickedFile = new File(this.currentDirectory.getAbsolutePath()
+ this.directoryEntries.get(selectionRowID));
break;
case ABSOLUTE:
clickedFile = new File(this.directoryEntries.get(selectionRowID));
break;
}
if(clickedFile.isFile())
this.Browse(clickedFile);
}
}
private void readFile() {
// what to write here???
}
对不起，我不能把图像，因为我没有名声，但是当我在我的模拟器中运行它得到这样的：
Sorry i cant put the image because i dont have reputation, but when i run it on my emulator a get something like this:
/mnt/sdcard/kuzmanic.c
/mnt/sdcard/text.txt
/mnt/sdcard/DCIM
/mnt/sdcard/LOST.DIR
所以，我想要做的是，当我点击我要在同一个布局文件打开那么的text.txt或kuzmanic.c文件，这是我的load.xml文件：
So what I want to do is when i click on the text.txt or kuzmanic.c file I want to open then in the same layout file, that is my load.xml file:
This is the code for the xml file:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:textSize="18sp">
</TextView>
我需要什么，在我的code写，我必须写在清单???什么
What i need to write in my code and do I have to write anything in the manifest???
推荐答案
试试这个code：
package com.javasamples;
import java.io.*;
import android.app.Activity;
import android.os.Bundle;
import android.view.*;
import android.view.View.OnClickListener;
import android.widget.*;
public class FileDemo2 extends Activity {
// GUI controls
EditText txtData;
Button btnWriteSDFile;
Button btnReadSDFile;
Button btnClearScreen;
Button btnClose;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// bind GUI elements with local controls
txtData = (EditText) findViewById(R.id.txtData);
txtData.setHint("Enter some lines of data here...");
btnWriteSDFile = (Button) findViewById(R.id.btnWriteSDFile);
btnWriteSDFile.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// write on SD card file data in the text box
try {
File myFile = new File("/sdcard/mysdfile.txt");
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
myOutWriter.append(txtData.getText());
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),
"Done writing SD 'mysdfile.txt'",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}// onClick
}); // btnWriteSDFile
btnReadSDFile = (Button) findViewById(R.id.btnReadSDFile);
btnReadSDFile.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// write on SD card file data in the text box
try {
File myFile = new File("/sdcard/mysdfile.txt");
FileInputStream fIn = new FileInputStream(myFile);
BufferedReader myReader = new BufferedReader(
new InputStreamReader(fIn));
String aDataRow = "";
String aBuffer = "";
while ((aDataRow = myReader.readLine()) != null) {
aBuffer += aDataRow + "\n";
}
txtData.setText(aBuffer);
myReader.close();
Toast.makeText(getBaseContext(),
"Done reading SD 'mysdfile.txt'",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}// onClick
}); // btnReadSDFile
btnClearScreen = (Button) findViewById(R.id.btnClearScreen);
btnClearScreen.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// clear text box
txtData.setText("");
}
}); // btnClearScreen
btnClose = (Button) findViewById(R.id.btnClose);
btnClose.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// clear text box
finish();
}
}); // btnClose
}// onCreate
}// AndSDcard
布局文件是
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:id="@+id/widget28"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ff0000ff"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<EditText
android:id="@+id/txtData"
android:layout_width="fill_parent"
android:layout_height="180px"
android:textSize="18sp" />
<Button
android:id="@+id/btnWriteSDFile"
android:layout_width="143px"
android:layout_height="44px"
android:text="1. Write SD File" />
<Button
android:id="@+id/btnClearScreen"
android:layout_width="141px"
android:layout_height="42px"
android:text="2. Clear Screen" />
<Button
android:id="@+id/btnReadSDFile"
android:layout_width="140px"
android:layout_height="42px"
android:text="3. Read SD File" />
<Button
android:id="@+id/btnClose"
android:layout_width="141px"
android:layout_height="43px"
android:text="4. Close" />
</LinearLayout>
这篇关于如何读取SD卡上的android选定的文本文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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