所以当我从互联网上下载2个xml文件时，我会被一个进度条作为启动画面而停滞不前。
到目前为止一切顺利，一切对我来说都很好 - 但此时我不知道如何继续。我的目标是让用户在启动画面上“等待”，直到应用程序完成下载。
我尝试将int“lenghtOfFile”从类传递给我的Main Activity。它对我来说无论如何都没有用。在下载内容时，基于Thread的进度条也不是正确的方法。
所以现在我想把Downloader作为AsyncTask放在我的MainActivity的末尾 - 但对于2个单独的文件，是否有任何优雅的方式进行两次下载？然后，获得一个进度条从0到100而不是两个条形从0到100计数是不是很棘手？
***更新
好的，我的Splash Screen和我的TextView在第一个File下载后更新了。 那么，我现在怎样才能在尽可能少的代码中进行第二次下载？我可以使用任何“while”或其他东西来做这件事吗？
我实现splashTread.start（）的方法是否正确; on onPostExecute（）？我希望在下载完成后我的启动画面退出
可选：我可以使用0 - 100％的下载状态更新TextView吗？
公共类Splashscreen扩展了Activity {
final String urlone = config.DL_DJ;
public boolean isNetworkAvailable() {
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
public void onAttachedToWindow() {
super.onAttachedToWindow();
Window window = getWindow();
window.setFormat(PixelFormat.RGBA_8888);
}
/** Called when the activity is first created. */
Thread splashTread;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splashscreen);
TextView splashstatus = (TextView) findViewById(R.id.spstatus);
if (isNetworkAvailable()) {
splashstatus.setText("ONLINE");
} else
{
splashstatus.setText("OFFLINE");
}
new MyTask().execute();
StartAnimations();
}
private void StartAnimations() {
Animation anim = AnimationUtils.loadAnimation(this, R.anim.alpha);
anim.reset();
LinearLayout l=(LinearLayout) findViewById(R.id.lin_lay);
l.clearAnimation();
l.startAnimation(anim);
anim = AnimationUtils.loadAnimation(this, R.anim.translate);
anim.reset();
ImageView iv = (ImageView) findViewById(R.id.splash);
iv.clearAnimation();
iv.startAnimation(anim);
splashTread = new Thread() {
@Override
public void run() {
try {
Intent intent = new Intent(Splashscreen.this,
MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(intent);
Splashscreen.this.finish();
} finally {
Splashscreen.this.finish();
}
}
};
}
private class MyTask extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
try {
URL url1 = new URL(urlone);
URLConnection ucon = url1.openConnection();
int lenghtOfFile = ucon.getContentLength();
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
Log.i("SPLASH LOGGER", "Got InputStream and BufferedInputStream");
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("Events.xml"),Context.MODE_PRIVATE);
Log.i("SPLASH LOGGER", "Got FileOutputStream and BufferedOutputStream");
byte data[] = new byte[1024];
//long total = 0;
int count;
//loop and read the current chunk
while ((count = bis.read(data)) != -1) {
//keep track of size for progress.
//total += count;
//write this chunk
bos.write(data, 0, count);
}
//Have to call flush or the file can get corrupted.
bos.flush();
bos.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
TextView splashstatus = (TextView) findViewById(R.id.spstatus);
splashstatus.setText("Done Downloading");
splashTread.start();
}
@Override
protected void onPreExecute()
{TextView splashstatus = (TextView) findViewById(R.id.spstatus);
splashstatus.setText("Start Downloading");
}
}
}
:: LOGCAT ::
08-17 22:15:23.154 32443-32505/? I/SPLASH LOGGER: Got InputStream and BufferedInputStream
08-17 22:15:23.154 32443-32505/? I/SPLASH LOGGER: Got FileOutputStream and BufferedOutputStream
08-17 22:15:23.155 32443-32505/? I/URL LOGGER: LINK HERE
08-17 22:15:23.156 32443-32505/? I/URL LOGGER: Events.xml
08-17 22:15:23.157 32443-32505/? I/URL LOGGER: 3
08-17 22:15:23.157 32443-32505/? I/progress: 33.333336
08-17 22:15:23.158 32443-32443/? I/String.valueOf values: 37.37226
08-17 22:15:23.158 32443-32443/? I/String.valueOf values: 74.74452
08-17 22:15:23.158 32443-32443/? I/String.valueOf values: 100.0
08-17 22:15:23.162 32443-32505/? I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
08-17 22:15:23.162 32443-32505/? I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
08-17 22:15:23.170 32761-32761/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.startService:1386 android.content.ContextWrapper.startService:656 android.content.ContextWrapper.startService:656 com.samsung.android.app.assistantmenu.AssistantMenuReceiver.onReceive:144 android.app.ActivityThread.handleReceiver:3309
08-17 22:15:23.329 29472-29472/? I/oneconnect[1.6.03-45_2]: FeatureUtil.isQcSupportedMode - user: 0
08-17 22:15:23.336 29253-29253/? I/ThemeManagerReceiver: ThemeManagerReceiver onReceive android.intent.action.PACKAGE_REPLACED
08-17 22:15:23.347 32443-32505/? I/SPLASH LOGGER: Got InputStream and BufferedInputStream
08-17 22:15:23.347 32443-32505/? I/SPLASH LOGGER: Got FileOutputStream and BufferedOutputStream
08-17 22:15:23.348 32443-32505/? I/URL LOGGER: LINK HERE
08-17 22:15:23.349 32443-32505/? I/URL LOGGER: overall.xml
08-17 22:15:23.349 32443-32505/? I/URL LOGGER: 3
08-17 22:15:23.349 32443-32505/? I/progress: 66.66667
08-17 22:15:23.350 32443-32505/? I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
08-17 22:15:23.351 32443-32505/? I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
08-17 22:15:23.353 32443-32443/? I/String.valueOf values: -68233.33
08-17 22:15:23.354 32443-32443/? I/String.valueOf values: -90099.99
08-17 22:15:23.480 32443-32505/? I/SPLASH LOGGER: Got InputStream and BufferedInputStream
08-17 22:15:23.480 32443-32505/? I/SPLASH LOGGER: Got FileOutputStream and BufferedOutputStream
08-17 22:15:23.482 32443-32443/? I/String.valueOf values: 100.0
注意，必须编辑一些值：
@Override
protected void onProgressUpdate(Float... values) {
TextView splashstatus = (TextView) findViewById(R.id.spstatus);
splashstatus.setText(String.valueOf(values[0]));
Log.i("String.valueOf values", String.valueOf(values[0]));
}
此处正在进行日志记录：
String urlStr = urls.keyAt(i);
Log.i("URL LOGGER",urls.keyAt(i));
OutputStream file = openFileOutput(urls.valueAt(i),Context.MODE_PRIVATE);
Log.i("URL LOGGER",urls.valueAt(i));
float fPercent = (((float)i)/urls.size())*100.0f;
Log.i("URL LOGGER", String.valueOf(urls.size()));
Log.i("progress", String.valueOf(fPercent));
答案 0 :(得分：0)
这是一个非常复杂的问题，所以我会尝试提供一些指导，而无需编写大量代码...
你的直觉是对的，你应该使用ASyncTask而不是使用Threads实现某种类型的IPC。具体来说，您可以使用publishProgress()和onProgressUpdate()（在UI线程上运行）的组合来更新视图中的ProgressBar。
您可以在下载完成后使用ASyncTask的onPostExecute()回调执行某些操作（退出启动画面）。
就同时进行两次下载而言，没有理由只能在ASyncTask中按顺序下载它们。在这种情况下你如何处理ProgressBar虽然我猜这是有趣的部分。我可能只是将ProgressBar的前50％作为第一个文件而后半部分是第二个文件。如果您愿意，我可以发布一些准系统代码。
更新：
我认为以下是处理此问题的一种非常优雅的方式。可以轻松扩展到2个以上的文件。我对其余代码做了一些假设，因此需要编辑。可能有错误，我没有运行它，但它应该给你一个想法去哪里：
private class MyTask extends AsyncTask<Void, Float, Void> {
@Override
protected Void doInBackground(Void... params) {
try {
ArrayMap<String, String> urls = new ArrayMap<String, String>();
urls.put(urlone, "Events.xml");
urls.put(urltwo, "Whatever.xml");
for (int i = 0; i < urls.size(); i ++) {
String urlStr = urls.keyAt(i);
String file = urls.valueAt(i);
float fPercent = (((float)i)/urls.size())*100.0f;
URL url = new URL(urlStr);
URLConnection ucon = url.openConnection();
int lengthOfFile = ucon.getContentLength();
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
Log.i("SPLASH LOGGER", "Got InputStream and BufferedInputStream");
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file), Context.MODE_PRIVATE);
Log.i("SPLASH LOGGER", "Got FileOutputStream and BufferedOutputStream");
byte data[] = new byte[1024];
long total = 0;
int count;
//loop and read the current chunk
while ((count = bis.read(data)) != -1) {
//keep track of size for progress.
total += count;
publishProgress(fPercent + (((float)total)/lengthOfFile)*100.0f);
bos.write(data, 0, count);
}
//Have to call flush or the file can get corrupted.
bos.flush();
bos.close();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onProgressUpdate(Float... values) {
TextView splashstatus = (TextView) findViewById(R.id.spstatus);
splashstatus.setText(values[0].toString());
}
}