是否存在一个与R平台无关的新线常量？我已经习惯了C＃，而Environment.NewLine会在Windows上返回\r\n，而\n会返回filesonserver <- unlist(strsplit(getURL(basePath, ftp.use.epsv=F, dirlistonly=T), "\n"))
。搜索没有任何结果，但我认为必须有某些东西，以便脚本可以独立于平台。
相关问题：有没有办法检测脚本运行的平台？由于其他原因（我还没有想到），这可能是有用的。
编辑：这就是我要问的原因。我从FTP服务器下载文件，但想获取文件列表，只下载服务器上本地不存在的文件。以下是我获取文件列表的方法：\r\n在Windows上，文件由\n分隔。在我的Mac上（我目前正在工作），它们被\n分开。我一直在寻找一种让这个平台独立的方法。我没有试过在窗口上用package com.example.listapp;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.app.ListFragment;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import static com.example.listapp.ItemData.Items.ORDERB;
import static com.example.listapp.ItemData.Items.TABLE_NAME;
import static com.example.listapp.ItemData.Items.TYPE;
import static com.example.listapp.ItemData.Items.LIST_TEXT;
public class MainActivity extends AppCompatActivity {
private ItemData ItemsDb;
String listText = null;
public static String[] FROM = { LIST_TEXT };
public static int[] TO = { R.id.list_text };
public static final Uri CONTENT_URI = Uri.parse("content://"
+ "com.example.listapp" + "/" + TABLE_NAME);
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ItemsDb = new ListData(getApplicationContext());
Intent saveIntent = getIntent();
listText = saveIntent.getStringExtra(ItemCreate.EXTRA_MESSAGE);
if (rlistText != null) {
SQLiteDatabase db = ItemsDb.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ORDERB, System.currentTimeMillis());
values.put(ITEM_TEXT, listText);
db.insertOrThrow(TABLE_NAME, null, values);
}
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
}
public void createItem(View view) {
Intent intent = new Intent(this, ItemCreate.class);
startActivity(intent);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.newInstance(position + 1);
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "List1";
case 1:
return "List2";
case 2:
return "List3";
}
return null;
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends ListFragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Cursor cursor = getActivity().getContentResolver().query(CONTENT_URI, FROM, null, null, "_ID DESC");
ListView listItems = getListView();
ListAdapter adapter = new SimpleCursorAdapter(getContext(), R.layout.list_item, cursor, FROM, TO, 0);
listItems.setAdapter(adapter);
}
}
}
分隔，这可能有效。可能还有一种方法可以将文件列表作为矢量而不必拆分它们，这样可以完全避免这种情况......
答案 0 :(得分：1)
软件包tryCatchLog具有函数determine.platform.NewLine()：
因此，如果您使用此字符串而不是硬编码的“ \ n”，则新行将独立于平台运行。
答案 1 :(得分：0)
最初问题的答案似乎是没有像C＃那样的新行常量。但正如评论所指出的那样，在我的案例中并不重要。直到我编辑了我可能不需要担心的细节之后，它才发生在我身上。即使包含\n返回的文件名的字符串被getURL()拆分，\r\n拆分也能在Windows上正常工作。