我正在尝试使用启动画面，然后在第一次打开应用程序时移动到下载屏幕。在应用程序第一次下载文件后，我希望它从启动画面到章节菜单屏幕再也不会打开下载程序活动
我有两个麻烦。
首先。我正在尝试使用共享偏好使其保存下载状态，并使用它来跳过下载器，如果以前曾经做过的话。我认为我不太了解共享偏好
二。下载进度脚本直接从0到100％。我尝试过使用Handler，我也试过使用runonUI但是没有运气。
任何帮助将不胜感激。我是java和android的新手。提前谢谢！
这是我的想法：
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
public class splashscreen extends Activity {
/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle SavedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(SavedInstanceState);
setContentView(R.layout.splashlayout);
SharedPreferences myPrefs = this.getSharedPreferences("DOWNLOAD_STATUS", MODE_WORLD_READABLE);
Update.storeDownloadStatusString(myPrefs.getString("DOWNLOAD_STATUS", "NotDownloaded"));
Thread timer = new Thread(){
public void run(){
try{
sleep(5000);
}
catch(InterruptedException e){
e.printStackTrace();
}
finally{
Intent checkDownloadIntentObject = new Intent("blah.blah.CHECKDOWNLOAD");
Intent chapterMenuObject = new Intent("blah.blah.CHAPTERMENU");
if (Update.getDownloadStatusString()=="NotDownloaded"){
startActivity(checkDownloadIntentObject);
}else{
startActivity(chapterMenuObject);
}
}
}
};
timer.start();
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
finish();
}
}
这是我的下载活动：
public class CheckDownload extends Activity {
public static int downloadedSize;
public static int totalSize;
// 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);
SharedPreferences myPrefs = this.getSharedPreferences("myPrefs", MODE_WORLD_READABLE);
final SharedPreferences.Editor prefsEditor = myPrefs.edit();
Thread downloader = new Thread() {
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://insert.url.here.blah");
// 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 folderdestination = new File(
Environment.getExternalStorageDirectory()
+ "/blah");
folderdestination.mkdir();
File file = new File(folderdestination, "blah.zip");
// create a new file, specifying the path, and the filename
// which we want to save the file as.
String fileurl = file.getAbsolutePath();
// 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
int totalSize = urlConnection.getContentLength();
// variable to store total downloaded bytes
int 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
Update.setDS(downloadedSize);
Update.setTS(totalSize);
updateProgress();
}
// close the output stream when done
fileOutput.close();
Unzipper.unzip(fileurl);
// catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
Intent chapterMenuIntentObject = new Intent(
"blah.blah.CHAPTERMENU");
prefsEditor.putString("DOWNLOAD_STATUS", "Downloaded");
prefsEditor.commit();
startActivity(chapterMenuIntentObject);
}
}
};
downloader.start();
}
protected void updateProgress() {
runOnUiThread(new Runnable() {
public void run() {
int dS=Update.getDS();
int tS=Update.getTS();
float percentage = dS / tS * 100;
String stringy = "Downloading!\n\n" +
"This will only happen the first time you open this application.\n\n" +
"This may take several minutes. Please be patient.\n\n" +
"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();
}
}
最后，这是update.java的代码：
public class Update{
public static int dsize;
public static int tsize;
public static String downloadStatusString;
public static void setDS(int ds){
dsize=ds;
}
public static int getDS(){
return dsize;
}
public static void setTS(int ts){
tsize=ts;
}
public static int getTS(){
return tsize;
}
public static void storeDownloadStatusString(String downloadStatus){
downloadStatusString=downloadStatus;
}
public static String getDownloadStatusString(){
return downloadStatusString;
}
}
答案 0 :(得分：1)
您应该使用AsyncTask来正确处理下载。
您正在写一个偏好但是从另一个偏好中读取。