我编写一个代码来下载带圆圈进度条的文件。但是文件没有下载到外部存储器，进度条不显示任何进度号。 logcat中没有显示错误。我的代码中没有错。帮我解决这个问题。这是我的代码。我在清单文件中添加了所有权限和活动类。提前谢谢。
package com.example.skr.downloader;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.os.PowerManager;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.ByteBuffer;
public class DownloaderClass extends Activity {
EditText txturl;
int progress=0;
public ProgressDialog progressDialog;
public DownloaderClass(){
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_download);
}
public void onDownload(View v){
txturl=(EditText)findViewById(R.id.txtURL);
progressDialog=new ProgressDialog(DownloaderClass.this);
final AsyncDownloaderClass asyncDownloaderClass=new AsyncDownloaderClass();
asyncDownloaderClass.execute("http://pinnest.net/newpinnest/wp-content/uploads/2013/08/1377250577ea43d.jpg");
}
class AsyncDownloaderClass extends AsyncTask<String,Integer, String>
{
private PowerManager.WakeLock mWakeLock;
Context context;
String filename, basename;
int fileLength;
DownloaderClass downloaderClass;
public AsyncDownloaderClass(){
downloaderClass=new DownloaderClass();
context=downloaderClass;
/*PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,getClass().getName());*/
}
protected void onPreExecute(){
// super.onPreExecute();
progressDialog.setMessage("Downloading....");
progressDialog.setTitle("Please Wait...");
progressDialog.setCanceledOnTouchOutside(false);
//progressDialog.setIndeterminate(false);
progressDialog.setProgress(progress);
//progressDialog.setMax(100);
progressDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
new AsyncDownloaderClass().cancel(true);
}
}
);
//mWakeLock.acquire();
progressDialog.show();
}
@Override
protected String doInBackground(String... params) {
//return null;
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
// expect HTTP 200 OK, so we don't mistakenly save error report
// instead of the file
Log.v("Do in background","calling.....");
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
input = connection.getInputStream();
BufferedInputStream bufferedInputStream=new BufferedInputStream(input);
fileLength = connection.getContentLength();
filename=url.getPath();
filename=filename.substring(filename.lastIndexOf('/') + 1);
output = new FileOutputStream(Environment.getExternalStorageDirectory().getPath()+"download.jpg");
byte data[] = new byte[1024];
long total = 0;
int count=0;
while ((count = input.read(data)) != -1) {
// allow canceling with back button
if (isCancelled()) {
input.close();
return null;
}
total += count;
// publishing the progress....
if (fileLength > 0) // only if total length is known
publishProgress((int) (total * 100 / fileLength));
output.write(data, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
} catch (IOException ignored) {
Log.v("Error","Error");
}
if (connection != null)
connection.disconnect();
}
return null;
}
protected void onProgressUpdate(Integer... values){
progressDialog.setProgress(values[0]);
progressDialog.setMessage("Downloading... " + values[0] + "%");
}
protected void onPostExecute(String... result){
progressDialog.dismiss();
if (result != null)
Toast.makeText(context,"Download error: "+result, Toast.LENGTH_LONG).show();
else
Toast.makeText(context,"File downloaded", Toast.LENGTH_SHORT).show();
}
}
}
清单文件
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.skr.downloader">
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission>
<application android:allowBackup="true" android:label="@string/app_name"
android:icon="@drawable/download" android:supportsRtl="true"
android:theme="@style/AppTheme"
>
<activity android:name="com.example.skr.downloader.LauncherClass">
<intent-filter>
<action android:name="android.intent.action.MAIN"></action>
<category android:name="android.intent.category.LAUNCHER"></category>
</intent-filter>
</activity>
<activity android:name=".DownloaderClass">
<intent-filter>
<action android:name="my.android.download"></action>
<category android:name="android.intent.category.DEFAULT"></category>
</intent-filter>
</activity>
</application>
</manifest>
答案 0 :(得分：0)
onPostExecute的签名是错误的。改变
protected void onPostExecute(String... result){
到
@Override
protected void onPostExecute(String result){.
现在它从未被调用过。并改变
output = new FileOutputStream(Environment.getExternalStorageDirectory().getPath()+"download.jpg");
到
output = new FileOutputStream(Environment.getExternalStorageDirectory().getPath()+"/download.jpg");