更新进度对话框 [英] Updating progress dialog
问题描述
我试图让一个应用程序,可以帮助我评估,以从网络资源下载文件的时间。我发现2个样品:
I am trying to make an application that can help me to evaluate the time to download the file from a web resource. I have found 2 samples:
<一个href="http://stackoverflow.com/questions/3028306/download-a-file-with-android-and-showing-the-progress-in-a-progressdialog">Download与Android的文件,并显示在一个ProgressDialog 进度
和
http://www.helloandroid.com/tutorials/如何下载-fileimage-URL-您的设备
第二个例子显示了一个更小的下载时间,但我不知道如何使用它来更新进度对话框。我认为有些事情应该,而EX pression在第二种情况下做到的,但我找不到什么。可能有人给我任何忠告?
The second example shows a smaller download time, but I cannot understand how to update progress dialog using it. I think something should be done with "while" expression in second case, but I cannot find what. Could someone give me any piece of advice?
UPD:
1日code:
try {
time1 = System.currentTimeMillis();
URL url = new URL(path);
URLConnection conexion = url.openConnection();
conexion.connect();
// this will be useful so that you can show a tipical 0-100% progress bar
int lenghtOfFile = conexion.getContentLength();
// downlod the file
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream("/sdcard/analyzer/test.jpg");
byte data[] = new byte[1024];
long total = 0;
time11 = System.currentTimeMillis();
while ((count = input.read(data)) != -1) {
total += count;
// publishing the progress....
publishProgress((int)(total*100/lenghtOfFile));
output.write(data, 0, count);
}
time22= System.currentTimeMillis()-time11;
output.flush();
output.close();
input.close();
} catch (Exception e) {}
timetaken = System.currentTimeMillis() - time1;
第2 code:
2nd code:
long time1 = System.currentTimeMillis();
DownloadFromUrl(path, "test.jpg");
long timetaken = System.currentTimeMillis() - time1;
其中,
public void DownloadFromUrl(String imageURL, String fileName) { //this is the downloader method
try {
URL url = new URL(imageURL); //you can write here any link
File file = new File(fileName);
/*Open a connection to that URL. */
URLConnection ucon = url.openConnection();
/*
* Define InputStreams to read from the URLConnection.
*/
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
/*
* Read bytes to the Buffer until there is nothing more to read(-1).
*/
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte) current);
}
/* Convert the Bytes read to a String. */
FileOutputStream fos = new FileOutputStream(PATH+file);
fos.write(baf.toByteArray());
fos.close();
} catch (IOException e) {
Log.d("ImageManager", "Error: " + e);
}
所以事情是,第一种方法似乎是慢30%左右。
So the thing is that first method seems to be slower for about 30%.
推荐答案
的的第二个例子可以运行得更快,但它垄断了GUI线程。该第一种方法,使用的 的AsyncTask
,效果较好;它允许GUI留响应作为下载所得。
The second example may run faster, but it monopolizes the GUI thread. The first approach, using AsyncTask
, is better; it allows the GUI to stay responsive as the download proceeds.
我觉得比较有帮助 的AsyncTask
与 的SwingWorker
,如本例如。
I found it helpful to compare AsyncTask
with SwingWorker
, as shown in this example.
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