我的应用程序downlods从一个链接，将其保存到SD卡的PDF文件，并​​且它的正常工作..但什么我struggeling的就是我不能让我的应用程序查看PDF文件。（尽管我在我的模拟器安装PDF阅读器）没有下载文件后会发生......这里是我的code为开扩PDF文件

 的InputStream输入=新的BufferedInputStream（url.openStream（））;            文件SD卡= Environment.getExternalStorageDirectory（）;            文件DIR =新的文件（sdCard.getAbsolutePath（）                    +/ MyApp的/下载）;            dir.mkdirs（）;            档案文件=新的文件（目录应用程序/ PDF格式）;            FileOutputStream中输出=新的FileOutputStream（文件）; 

解决方案

使用低于code打开PDF文件。

 文件pdfFile =新的文件（到/ mnt / SD卡/文件路径/ yourpdf.pdf）;    如果（pdfFile.exists（））{        URI路径= Uri.fromFile（pdfFile）;        意图pdfIntent =新意图（Intent.ACTION_VIEW）;        pdfIntent.setDataAndType（路径，应用程序/ PDF格式）;        pdfIntent.setFlags（Intent.FLAG_ACTIVITY_CLEAR_TOP）;        尝试{           startActivity（pdfIntent）;        }赶上（ActivityNotFoundException E）{           Toast.makeText（yourActivityClass.this，没有可用来查看PDF应用程序，Toast.LENGTH_LONG）.show（）;        }    }其他{        Toast.makeText（yourActivityClass.this，找不到文件，Toast.LENGTH_LONG）.show（）;    } 

yourActivityClass.this 是应用程序上下文使其正确而高于code测试。

my app downlods a pdf file from a link saving it to SD card, and it's working fine.. but what I'm struggeling at is I couldn't let my app views the pdf file..( although I've installed PDF viewer on my emulator)nothing happens after downloading the file... here's my code for openning the pdf file

                                   InputStream input = new BufferedInputStream(url.openStream());
            File sdCard = Environment.getExternalStorageDirectory();
            File dir = new File(sdCard.getAbsolutePath()
                    + "/myapp/download");
            dir.mkdirs();
            File file = new File(dir, "application/pdf");
            FileOutputStream output = new FileOutputStream(file);

Use below code to open pdf file.

File pdfFile = new File("/mnt/sdcard/path_to_file/yourpdf.pdf"); 
    if(pdfFile.exists()) {
        Uri path = Uri.fromFile(pdfFile); 
        Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
        pdfIntent.setDataAndType(path, "application/pdf");
        pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        try {
           startActivity(pdfIntent);
        } catch(ActivityNotFoundException e) {
           Toast.makeText(yourActivityClass.this, "No Application available to view pdf", Toast.LENGTH_LONG).show(); 
        }
    } else {
        Toast.makeText(yourActivityClass.this, "File not found", Toast.LENGTH_LONG).show(); 
    }

yourActivityClass.this is application context make it correct while testing above code.