我想通过获取从EditText输入的文本来将一个文件保存到内部存储。然后我想要相同的文件以字符串形式返回输入的文本，并将其保存到稍后使用的另一个字符串中。
代码如下:
package com.omm.easybalancerecharge;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText num = (EditText) findViewById(R.id.sNum);
Button ch = (Button) findViewById(R.id.rButton);
TelephonyManager operator = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String opname = operator.getNetworkOperatorName();
TextView status = (TextView) findViewById(R.id.setStatus);
final EditText ID = (EditText) findViewById(R.id.IQID);
Button save = (Button) findViewById(R.id.sButton);
final String myID = ""; //When Reading The File Back, I Need To Store It In This String For Later Use
save.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//Get Text From EditText "ID" And Save It To Internal Memory
}
});
if (opname.contentEquals("zain SA")) {
status.setText("Your Network Is: " + opname);
} else {
status.setText("No Network");
}
ch.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//Read From The Saved File Here And Append It To String "myID"
String hash = Uri.encode("#");
Intent intent = new Intent(Intent.ACTION_CALL);
intent.setData(Uri.parse("tel:*141*" + /*Use The String With Data Retrieved Here*/ num.getText()
+ hash));
startActivity(intent);
}
});
}
我已经包括了评论，以帮助您进一步分析我的观点，即我希望在哪里执行操作/使用变量。
检查下面的代码。
从文件系统中的文件读取。
FileInputStream fis = null;
try {
fis = context.openFileInput(fileName);
InputStreamReader isr = new InputStreamReader(fis);
// READ STRING OF UNKNOWN LENGTH
StringBuilder sb = new StringBuilder();
char[] inputBuffer = new char[2048];
int l;
// FILL BUFFER WITH DATA
while ((l = isr.read(inputBuffer)) != -1) {
sb.append(inputBuffer, 0, l);
}
// CONVERT BYTES TO STRING
String readString = sb.toString();
fis.close();
catch (Exception e) {
} finally {
if (fis != null) {
fis = null;
}
}
下面的代码是将文件写入内部文件系统。
FileOutputStream fos = null;
try {
fos = context.openFileOutput(fileName, Context.MODE_PRIVATE);
fos.write(stringdatatobestoredinfile.getBytes());
fos.flush();
fos.close();
} catch (Exception e) {
} finally {
if (fos != null) {
fos = null;
}
}
我想这对你有帮助。
我们可以使用这段代码将String写入文件
public static void writeTextToFile(final String filename, final String data) {
File file = new File(filename);
try {
FileOutputStream stream = new FileOutputStream(file);
stream.write(data.getBytes());
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
然后在Main代码中，我们使用这个
writeTextToFile(getExternalFilesDir("/").getAbsolutePath() + "/output.txt", "my-example-text");
之后，检查Android/data/<package-name>/files文件。
科特林
class FileReadWriteService {
private var context:Context? = ContextHolder.instance.appContext
fun writeFileOnInternalStorage(fileKey: String, sBody: String) {
val file = File(context?.filesDir, "files")
try {
if (!file.exists()) {
file.mkdir()
}
val fileToWrite = File(file, fileKey)
val writer = FileWriter(fileToWrite)
writer.append(sBody)
writer.flush()
writer.close()
} catch (e: Exception) {
Logger.e(classTag, e)
}
}
fun readFileOnInternalStorage(fileKey: String): String {
val file = File(context?.filesDir, "files")
var ret = ""
try {
if (!file.exists()) {
return ret
}
val fileToRead = File(file, fileKey)
val reader = FileReader(fileToRead)
ret = reader.readText()
reader.close()
} catch (e: Exception) {
Logger.e(classTag, e)
}
return ret
}
}
希望这对你有用。
写文件:
private void writeToFile(String data,Context context) {
try {
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("config.txt", Context.MODE_PRIVATE));
outputStreamWriter.write(data);
outputStreamWriter.close();
}
catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
}
阅读文件:
private String readFromFile(Context context) {
String ret = "";
try {
InputStream inputStream = context.openFileInput("config.txt");
if ( inputStream != null ) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String receiveString = "";
StringBuilder stringBuilder = new StringBuilder();
while ( (receiveString = bufferedReader.readLine()) != null ) {
stringBuilder.append("\n").append(receiveString);
}
inputStream.close();
ret = stringBuilder.toString();
}
}
catch (FileNotFoundException e) {
Log.e("login activity", "File not found: " + e.toString());
} catch (IOException e) {
Log.e("login activity", "Can not read file: " + e.toString());
}
return ret;
}
