嘗試從PDF下載PDF文件的代碼文檔不被查看

我試圖從Dropbox下載PDF文件的代碼，並在單擊項目時下載了我的SD卡中的所有文件後，PDF書籍應以PDF格式加載查看器系統應用。但實際上通過使用此代碼所有的PDF文件正在下載，但是當PDF應用程序被加載時，它顯示錯誤「文檔無法打開」，PDF書不被查看。任何人都可以請幫我排序這個問題提前感謝你而我不擅長以有效的方式發佈問題，所以我真的很抱歉提前。嘗試從PDF下載PDF文件的代碼文檔不被查看

{ 

    MainActivity 
    package com.example.mahvishponum.pdfviewer; 

    import android.app.Activity; 
    import android.app.ProgressDialog; 
    import android.content.DialogInterface; 
    import android.content.Intent; 
    import android.net.Uri; 
    import android.os.Environment; 
    import android.support.v7.app.AppCompatActivity; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.widget.AdapterView; 
    import android.widget.ListView; 
    import android.widget.Toast; 

    import java.io.File; 
    import java.util.ArrayList; 

    public class MainActivity extends Activity implements AsyncResponse { 

    ProgressDialog mProgressDialog; 
    ListView list; 
    int counter = 0; 

    ArrayList<DataModel> _data = new ArrayList<>(); 
    String[] web = { 
     "A Textbook of Paediatric Orthopaedics" + 
       "By Nigel S. Broughton", 
     "Basic Pediatric Protocols 2013" + 
       "By Ministry of Health Kenya", 
     "Basic Pediatric Protocols 2016" + 
       "By Ministry of Health Kenya", 

     "Current Diagnosis & Treatment" + 
       "PEDIATRICS 19th Edition" + 
       "By McGrawHill LANGE", 
     "Hospital Care For Children" + 
       "Pocket Book 2013 Edition" + 
       "By WHO", 
     "Textbook of Pediatrics" + 
       "20th Edition" + 
       "By Nelson", 
     "The Care and Feeding of Children" + 
       "By L. Emmett Holt. M. D.", 
     "Updates on the Management of Severe Acute Malnutrition in Infants 
      and Children" + 
       "Guidelines by WHO" 
}; 
String[] titles = { 
     "helptextbookpedortho.pdf", 
     "BasicPaediatricProcotolsNovember2013.pdf", 
     "basicpaediatricprotocols2016.pdf", 
     "currentdiagnosisandtreatmentpediatrics.pdf", 
     "HospitalCareForChildrenPocketBooks.pdf", 
     "NelsonTextbookofPediatrics.pdf", 
     "TheCareAndFeedingOfChildren.pdf" 
}; 
String[] urls = { 
     "https://www.dropbox.com/s/ruds35lyz672jjk/helptextbookpedortho.pdf?dl=1", 
     "https://www.dropbox.com/s/n2snurxnvijbqya/BasicPaediatricProcotolsNovember2013.pdf?dl=1", 
     "https://www.dropbox.com/s/a1tyrfqd5jhdu7k/basicpaediatricprotocols2016.pdf?dl=1", 
     "https://www.dropbox.com/s/hgs7pp97ut3mti3/currentdiagnosisandtreatmentpediatrics.pdf?dl=1", 
     "https://www.dropbox.com/s/gvz2805gj39hbc4/HospitalCareForChildrenPocketBooks.pdf?dl=1", 
     "https://www.dropbox.com/s/avlj81qctl83otk/NelsonTextbookofPediatrics.pdf?dl=1", 
     "https://www.dropbox.com/s/j0e5p9hx6jwf2kg/TheCareAndFeedingOfChildren.pdf?dl=1", 
     "https://www.dropbox.com/s/xtfurbb0umbns03/WHOMalnutritionGuidelines.pdf?dl=1" 
}; 
Integer[] imageId = { 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book, 
     R.drawable.book 

}; 

void filSdCard() { 
    mProgressDialog = new ProgressDialog(MainActivity.this); 
    mProgressDialog.setIndeterminate(true); 
    mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); 
    mProgressDialog.setCancelable(true); 

    if (counter < urls.length) { 

     final Downloader downloadTask = new Downloader(MainActivity.this, mProgressDialog, titles[counter], urls[counter],counter); 
     downloadTask.delegate = MainActivity.this; 
     downloadTask.execute(); 
     mProgressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() { 
      @Override 
      public void onCancel(DialogInterface dialog) { 
       downloadTask.cancel(true); 
      } 
     }); 

    } 


} 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.pdfviewer); 

    CustomList adapter = new 
      CustomList(MainActivity.this, web, imageId); 
    list = (ListView) findViewById(R.id.listvid); 
    list.setAdapter(adapter); 
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
           int position, long id) { 

     //give the title according to the title of your disease. every file 
     should have different title. 
      if (ifFileExists(titles[position])) { 
       String filePath = Environment.getExternalStorageDirectory() + "/Pediatric/" + "helptextbookpedortho.pdf"; 

       Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(filePath)); 
       intent.setDataAndType(Uri.parse(filePath), "application/pdf"); 
       startActivity(intent); 
      } else { 
       //constructor contains url as well as title with which the file will be saved. make sure you give the same title here and above. 
       //Also look at the url im using. you can see these files on your dropbox and see we have a different url. upload file to dropbox and make it public to get url, then compare it with any 
       //of these urls, you will know what to replace. 
       filSdCard(); 

      } 
     } 
    }); 
} 

boolean ifFileExists(String title) { 
    String root = Environment.getExternalStorageDirectory().toString(); 
    File myDir = new File(root + "/Pediatric"); 
    myDir.mkdirs(); 
    File file = new File(myDir, title); 
    if (file.exists()) { 
     return true; 
    } else 
     return false; 
} 

@Override 
public void processFinish(String output) { 
    if (output.equals("Success")) { 
     if (counter < urls.length) { 
      counter = counter + 1; 
      filSdCard(); 
     } 

    } else { 
     if(mProgressDialog.isShowing()) 
      mProgressDialog.dismiss(); 
     Toast.makeText(getApplicationContext(), "Some error occured!", Toast.LENGTH_LONG).show(); 
    } 

} 

private class DataModel { 
    String Title = ""; 
    String Url = ""; 

    public String getTitle() { 
     return Title; 
    } 

    public void setTitle(String title) { 
     Title = title; 
    } 

    public String getUrl() { 
     return Url; 
    } 

    public void setUrl(String url) { 
     Url = url; 
    } 
} 
} 
} 











Downloader.java 
package com.example.mahvishponum.pdfviewer; 

import android.app.ProgressDialog; 
import android.content.Context; 
import android.os.AsyncTask; 
import android.os.Environment; 
import android.os.PowerManager; 
import android.widget.Toast; 

import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.net.HttpURLConnection; 
import java.net.URL; 

/** 
* Created by Mahvish on 6/6/2017. 
*/ 

public class Downloader extends AsyncTask<String, Integer, String> { 
ProgressDialog mProgressDialog; 
private Context context; 
String title=""; 
public AsyncResponse delegate = null; 
int counter=0; 
private PowerManager.WakeLock mWakeLock; 
String urlString =""; 
public Downloader(Context context, ProgressDialog mProgressDialog, String 
title, String urlString, int counter) { 
    this.context = context; 
    this.mProgressDialog = mProgressDialog; 
    this.title = title; 
    this.urlString = urlString; 
    this.counter = counter; 

} 

@Override 
protected String doInBackground(String... sUrl) { 
    InputStream input = null; 
    OutputStream output = null; 
    HttpURLConnection connection = null; 
    try { 
     URL url = new URL(urlString); 
     connection = (HttpURLConnection) url.openConnection(); 
     connection.connect(); 

     // expect HTTP 200 OK, so we don't mistakenly save error report 
     // instead of the file 
     if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) { 
      return "Server returned HTTP " + connection.getResponseCode() 
        + " " + connection.getResponseMessage(); 
     } 

     // this will be useful to display download percentage 
     // might be -1: server did not report the length 
     int fileLength = connection.getContentLength(); 

     // download the file 
     input = connection.getInputStream(); 
     String root = Environment.getExternalStorageDirectory().toString(); 
     File myDir = new File(root + "/Pediatric"); 
     myDir.mkdirs(); 
     File file = new File(myDir, title); 

     output = new FileOutputStream(file); 

     byte data[] = new byte[4096]; 
     long total = 0; 
     int count; 
     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) { 
     } 

     if (connection != null) 
      connection.disconnect(); 
    } 
    return null; 
    } 

    @Override 
    protected void onPreExecute() { 
    super.onPreExecute(); 
    // take CPU lock to prevent CPU from going off if the user 
    // presses the power button during download 
    PowerManager pm = (PowerManager) 
    context.getSystemService(Context.POWER_SERVICE); 
    mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, 
      getClass().getName()); 
    mWakeLock.acquire(); 
    mProgressDialog.setMessage("Downloading "+(counter+1)+"/"+8); 
    mProgressDialog.show(); 
} 

    @Override 
    protected void onProgressUpdate(Integer... progress) { 
    super.onProgressUpdate(progress); 
    // if we get here, length is known, now set indeterminate to false 
    mProgressDialog.setIndeterminate(false); 
    mProgressDialog.setMax(100); 
    mProgressDialog.setSecondaryProgress(30); 

    mProgressDialog.setProgress(progress[0]); 
    } 

    @Override 
    protected void onPostExecute(String result) { 
    mWakeLock.release(); 
    mProgressDialog.dismiss(); 
    if (result != null) { 
     Toast.makeText(context, "Download error: " + result, 
    Toast.LENGTH_LONG).show(); 

     delegate.processFinish("Error"); 

    } else { 
     delegate.processFinish("Success"); 

     /* String mediaPath = Environment.getExternalStorageDirectory() + 
    "/Pediatric/" + title; 

     Intent intent = new Intent(Intent.ACTION_VIEW, 
    Uri.parse(mediaPath)); 
     intent.setDataAndType(Uri.parse(mediaPath), "video/mp4"); 
     context. startActivity(intent);*/ 
    } 
    } 
} 







AsyncResponse Inteerface 
package com.example.mahvishponum.pdfviewer; 

/** 
* Created by Mahvish on 12/22/2016. 
    */ 

public interface AsyncResponse { 
void processFinish(String output); 

} 







pdfviewer.xml 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context=".MainActivity" > 

<ListView 
    android:id="@+id/listvid" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" > 

</ListView> 

</RelativeLayout> 







Menifest.xml 

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example.mahvishponum.pdfviewer"> 

<uses-permission android:name="android.permission.WAKE_LOCK"/> 
<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
<uses-permission android:name="android.permission.GET_ACCOUNTS" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
<uses-permission android:name="android.permission.READ_PHONE_STATE" /> 
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> 


<application 
    android:allowBackup="true" 
    android:icon="@mipmap/ic_launcher" 
    android:label="@string/app_name" 
    android:roundIcon="@mipmap/ic_launcher_round" 
    android:supportsRtl="true" 
    android:theme="@style/AppTheme"> 
    <activity android:name=".MainActivity"> 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 


    </application> 

    </manifest> 

CustomList.java 
package com.example.mahvishponum.pdfviewer; 

import android.app.Activity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class CustomList extends ArrayAdapter<String>{ 

private final Activity context; 
private final String[] web; 
private final Integer[] imageId; 
public CustomList(Activity context, 
       String[] web, Integer[] imageId) { 
    super(context, R.layout.list_single, web); 
    this.context = context; 
this.web = web; 
this.imageId = imageId; 

} 
@Override 
    public View getView(int position, View view, ViewGroup parent) { 
LayoutInflater inflater = context.getLayoutInflater(); 
    View rowView= inflater.inflate(R.layout.list_single, null, true); 
TextView txtTitle = (TextView) rowView.findViewById(R.id.txt); 

ImageView imageView = (ImageView) rowView.findViewById(R.id.img); 
txtTitle.setText(web[position]); 

    imageView.setImageResource(imageId[position]); 
    return rowView; 
} 
} 


list_single.xml 

<?xml version="1.0" encoding="utf-8"?> 
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" > 
    <TableRow> 
    <ImageView 
     android:id="@+id/img" 
     android:layout_width="50dp" 
     android:layout_height="50dp"/> 

    <TextView 
     android:id="@+id/txt" 
     android:layout_width="wrap_content" 
     android:layout_height="50dp" /> 

</TableRow> 
</TableLayout>

來源

2017-07-20 مہوش پونم

你可以從普通的數據文件管理器/自己的文件打開它嗎？如果這不工作，下載出錯

下面的代碼更改爲此在MainActivity：

@Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     CustomList adapter = new CustomList(MainActivity.this, web, imageId); 
     list = (ListView) findViewById(R.id.listvid); 
     list.setAdapter(adapter); 
     list.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
            int position, long id) { 

       //give the title according to the title of your disease. every file 
       //should have different title. 
       if (ifFileExists(titles[position])) { 
        String filePath = Environment.getExternalStorageDirectory() + "/Pediatric/" + "helptextbookpedortho.pdf"; 
        File f = new File(filePath); 
        Log.d("Main","file exits " + f.exists()); 
        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(filePath)); 
        intent.setDataAndType(Uri.fromFile(f), "application/pdf"); 
        //intent.setDataAndType(Uri.parse(filePath), "application/pdf"); 
        startActivity(intent); 
       } else { 
        //constructor contains url as well as title with which the file will be saved. make sure you give the same title here and above. 
        //Also look at the url im using. you can see these files on your dropbox and see we have a different url. upload file to dropbox and make it public to get url, then compare it with any 
        //of these urls, you will know what to replace. 
        filSdCard(); 

       } 
      } 
     }); 
    }

我已經改變了這一行：

File f = new File(filePath); 
intent.setDataAndType(Uri.fromFile(f), "application/pdf");

來源

2017-07-20 18:06:37

是所有文件都看我打開文件管理器， –

但我想查看它時單擊列表項 –

是的，我知道，但現在我們知道它在代碼中出錯了;） –

嘗試從PDF下載PDF文件的代碼文檔不被查看

回答

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