Android 6.0+ 项目开发中用到适配功能

  // 启动安装
    public void apkInstallMethod(View view){
        //File file = new File(Environment.getExternalStorageDirectory(), "actionbar.apk");
        File file = new File(getFilesDir(),"actionbar.apk");
        Log.e("denganzhi1",file.getAbsolutePath());
        if(file.exists()==false){
            copyDB("actionbar.apk");   // 把assert下actionbar.apk 拷贝的 /data/data/packageName/file 下 , 没有安装包
            Toast.makeText(ApkInstallActivity.this,"文件不存在",Toast.LENGTH_SHORT).show();
            return;
        }
        Uri fileUri = null;
        Intent intent = new Intent(Intent.ACTION_VIEW);
        if (Build.VERSION.SDK_INT >= 24) {
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
      // 这里对应AndroidManifest.xml 配置authorities  com.denganzhi.permission
            fileUri = FileProvider.getUriForFile(this, "com.denganzhi.permission", file);
        } else {
            fileUri = Uri.fromFile(file);
        }
            intent.setDataAndType(fileUri,
                    "application/vnd.android.package-arcHive");
            startActivity(intent);
    }
    private void copyDB(final String dbname) {
        new Thread(){
            public void run() {
                try {
                    File file = new File(getFilesDir(),dbname);
                    if(file.exists()&&file.length()>0){
                        Log.e("denganzhi1","数据库是存在的。无需拷贝");
                        return ;
                    }
                    InputStream is = getAssets().open(dbname);
                    FileOutputStream fos  = openFileOutput(dbname, MODE_PRIVATE);
                    byte[] buffer = new byte[1024];
                    int len = 0;
                    while((len = is.read(buffer))!=-1){
                        fos.write(buffer, 0, len);
                    }
                    is.close();
                    fos.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            };
        }.start();
    }