唉，尝试了好半天了，才弄懂，
1、首先权限的问题
我们需要在根文件中添加权限:<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
2、上面两篇博客可以参考，一个告诉你如何查看文件的绝对路径，一个说明如何借助文件管理器选中文件
3、这里我的绝对路径是
final String FILE_NAME = "/storage/emulated/0/updatebin/update.txt"; 我把文件在手机里呢
4、点击按钮读文件内容，下面两个函数都行
btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
dis.setText(readFileSdcardFile(FILE_NAME));
dis.setText(readSDFile(FILE_NAME));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
public String readSDFile(String fileName) throws IOException {
File file = new File(fileName);
FileInputStream fis = new FileInputStream(file);
int length = fis.available();
byte [] buffer = new byte[length];
fis.read(buffer);
String res = EncodingUtils.getString(buffer, "UTF-8");
fis.close();
return res;
}
public String readFileSdcardFile(String fileName) throws IOException{
String res="";
try{
FileInputStream fin = new FileInputStream(fileName);
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return res;
}
5、之前的博客里面说的函数也贴过来吧
在这个目录下 /storage/emulated/0/updatebin 搜索所有带keyword关键词的文件和文件夹 可以用来查看文件的绝对路径
权限:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
private String searchFile(String keyword) {
String result = "";
File[] files = new File("/storage/emulated/0/updatebin").listFiles();
for (File file : files) {
if (file.getName().indexOf(keyword) >= 0) {
result += file.getPath() + "\n";
}
}
if (result.equals("")){
result = "找不到文件!!";
}
return result;
}
6、按钮下 可以调用管理器选择文件 并输出文件信息
打开文件管理器选择文件
private void showFileChooser() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityForResult(Intent.createChooser(intent, "请选择一个要上传的文件"),
FILE_SELECT_CODE);
} catch (android.content.ActivityNotFoundException ex) {
// Potentially direct the user to the Market with a Dialog
Toast.makeText(MainActivity, "请安装文件管理器", Toast.LENGTH_SHORT)
.show();
}
}
private void chooseFile() throws IOException {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityForResult(Intent.createChooser(intent, "选择文件"), FILE_SELECT_CODE);
} catch (android.content.ActivityNotFoundException ex) {
Toast.makeText(this, "亲，木有文件管理器啊-_-!!", Toast.LENGTH_SHORT).show();
}
}
选择的文件的结果 这里输出文件绝对路径信息 Uri uri = data.getData();
Log.i(TAG, "------->" + uri.getPath());
@Override public void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub if (resultCode != Activity.RESULT_OK) { super.onActivityResult(requestCode,
resultCode, data); return; } if (requestCode == FILE_SELECT_CODE) { Uri uri = data.getData(); Log.i(TAG, "------->" + uri.getPath()); // dis.setText(read()); //readFileOnLine(FILE_NAME); } super.onActivityResult(requestCode, resultCode, data); }
7、最后贴上自己完整的代码
按钮点击 打开文件管理器 选择某个文件 并输出文件里面的内容
final String FILE_NAME = "/storage/emulated/0/updatebin/update.txt";
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dis=(TextView) findViewById(R.id.textView1);
btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
chooseFile();//按键点击打开文件管理器
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
private void chooseFile() throws IOException {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityForResult(Intent.createChooser(intent, "选择文件"), FILE_SELECT_CODE);
} catch (android.content.ActivityNotFoundException ex) {
Toast.makeText(this, "亲，木有文件管理器啊-_-!!", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if (resultCode != Activity.RESULT_OK) {
super.onActivityResult(requestCode, resultCode, data);
return;
}
if (requestCode == FILE_SELECT_CODE) {
Uri uri = data.getData();
Log.i(TAG, "------->" + uri.getPath());
try {
//dis.setText(readFileSdcardFile(FILE_NAME));
dis.setText(readFileSdcardFile(uri.getPath()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
super.onActivityResult(requestCode, resultCode, data);
}
public String readFileSdcardFile(String fileName) throws IOException{
String res="";
try{
FileInputStream fin = new FileInputStream(fileName);
int length = fin.available();
byte [] buffer = new byte[length];
fin.read(buffer);
res = EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return res;
}
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