Очевидно, что вы должны получить этот тип ошибки, так как текущий поток, который вы работаете, не может обновить GUI. Чтобы обновить графический интерфейс, вы должны понимать концепцию обработчика в Android.* Обработчик в Android.
Я думаю, что вы должны изменить свой код, как показано ниже: -
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.widget.TextView;
public class CheckDownload extends Activity {
private TextView textytext;
private int totalSize;
private int downloadedSize = 0;
private TimerThread timer = new TimerThread();
/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle SavedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(SavedInstanceState);
setContentView(R.layout.downloadscreen);
timer.start();
}
public void updateProgress(int downloadedSize, int totalSize) {
int percentage = downloadedSize / totalSize * 100;
String stringy = "Download Progress: " + percentage + "%";
TextView textytext = (TextView) findViewById(R.id.downloadscreentextview);
textytext.setText(stringy);
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
finish();
}
private class TimerThread extends Thread {
@Override
public void run() {
try {
// set the download URL, a url that points to a file on the
// internet
// this is the file to be downloaded
URL url = new URL(
"http://www.android.com/media/wallpaper/gif/android_logo.gif");
// create the new connection
HttpURLConnection urlConnection = (HttpURLConnection) url
.openConnection();
// set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
// and connect!
urlConnection.connect();
// set the path where we want to save the file
// in this case, going to save it on the root directory of
// the
// sd card.
File SDCardRoot = Environment.getExternalStorageDirectory();
// create a new file, specifying the path, and the filename
// which we want to save the file as.
File file = new File(SDCardRoot, "android_logo.gif");
// this will be used to write the downloaded data into the
// file we created
FileOutputStream fileOutput = new FileOutputStream(file);
// this will be used in reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
// this is the total size of the file
totalSize = urlConnection.getContentLength();
// variable to store total downloaded bytes
downloadedSize = 0;
// create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0; // used to store a temporary size of
// the buffer
// now, read through the input buffer and write the contents
// to the file
while ((bufferLength = inputStream.read(buffer)) > 0) {
// add the data in the buffer to the file in the file
// output stream (the file on the sd card
fileOutput.write(buffer, 0, bufferLength);
// add up the size so we know how much is downloaded
downloadedSize += bufferLength;
// this is where you would do something to report the
// prgress, like this maybe
handler.sendEmptyMessage(0);
}
// close the output stream when done
fileOutput.close();
// catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
handler.sendEmptyMessage(1);
}
}
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 0:
updateProgress(downloadedSize, totalSize);
break;
case 1:
Intent chapterMenuIntentObject = new Intent(
"com.blah.blah.CHAPTERMENU");
startActivity(chapterMenuIntentObject);
}
}
};
}