Java 无法将字节转换为KB
我有一个android videoplayer,它在SD卡上显示所有视频,带有名称和文件大小,但大小以字节显示,我无法将其转换为KB、MB、GB等。我尝试将int值除以1024,但它不起作用。它打印的值错误。有人能帮忙吗 SDVideos.javaJava 无法将字节转换为KB,java,android,xml,user-interface,android-video-player,Java,Android,Xml,User Interface,Android Video Player,我有一个android videoplayer,它在SD卡上显示所有视频,带有名称和文件大小,但大小以字节显示,我无法将其转换为KB、MB、GB等。我尝试将int值除以1024,但它不起作用。它打印的值错误。有人能帮忙吗 SDVideos.java import android.app.Activity; import android.content.ContentResolver; import android.content.Context; import android.database.
import android.app.Activity;
import android.content.ContentResolver;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import java.text.DecimalFormat;
public class SDVideos extends Activity
{
private Cursor videoCursor;
int videoColumnIndex;
ListView videolist;
int count;
String[] thumbColumns = { MediaStore.Video.Thumbnails.DATA,MediaStore.Video.Thumbnails.VIDEO_ID };
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sdvideos);
initialization();
}
private void initialization()
{
System.gc();
String[] videoProjection = { MediaStore.Video.Media._ID,MediaStore.Video.Media.DATA,
MediaStore.Video.Media.DISPLAY_NAME,MediaStore.Video.Media.SIZE };
videoCursor =getContentResolver().query(MediaStore.Video.Media.EXTERNAL_CONTENT_URI,videoProjection, null, null, null);
count = videoCursor.getCount();
videolist = (ListView) findViewById(R.id.PhoneVideoList);
videolist.setAdapter(new VideoListAdapter(this.getApplicationContext()));
videolist.setOnItemClickListener(videogridlistener);
}
private AdapterView.OnItemClickListener videogridlistener = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position, long id)
{
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
videoCursor.moveToPosition(position);
String filename = videoCursor.getString(videoColumnIndex);
Log.i("FileName: ", filename);
//Intent intent = new Intent(VideoActivity.this, ViewVideo.class);
//intent.putExtra("videofilename", filename);
//startActivity(intent);
}};
public class VideoListAdapter extends BaseAdapter
{
private Context vContext;
public VideoListAdapter(Context c)
{
vContext = c;
}
public int getCount()
{
return videoCursor.getCount();
}
public Object getItem(int position)
{
return position;
}
public long getItemId(int position)
{
return position;
}
public View getView(int position, View convertView, ViewGroup parent)
{
View listItemRow;
listItemRow = LayoutInflater.from(vContext).inflate(R.layout.listitem, parent, false);
TextView txtTitle = (TextView)listItemRow.findViewById(R.id.txtTitle);
TextView txtSize = (TextView)listItemRow.findViewById(R.id.txtSize);
ImageView thumbImage = (ImageView)listItemRow.findViewById(R.id.imgIcon);
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME);
videoCursor.moveToPosition(position);
txtTitle.setText(videoCursor.getString(videoColumnIndex));
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE);
videoCursor.moveToPosition(position);
txtSize.setText(" Size(KB):" + (videoCursor.getString(videoColumnIndex/205870)));
int videoId = videoCursor.getInt(videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
ContentResolver crThumb = getContentResolver();
BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize = 1;
Bitmap curThumb = MediaStore.Video.Thumbnails.getThumbnail(crThumb, videoId, MediaStore.Video.Thumbnails.MICRO_KIND, options);
thumbImage.setImageBitmap(curThumb);
return listItemRow;
}
}
}
列表项。xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp">
<ImageView android:id="@+id/imgIcon"
android:layout_width="90dip"
android:layout_height="90dip"
android:paddingLeft="10dip"
android:paddingRight="10dip"/>
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginRight="10dip">
<TextView android:id="@+id/txtTitle"
android:layout_width="250dip"
android:layout_height="wrap_content"
android:gravity="left"
android:textStyle="normal"
android:textSize="15dp"
android:textColor="#FF0000"
android:paddingTop="30dp"
android:paddingLeft="20dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp" />
<TextView android:id="@+id/txtSize"
android:layout_width="250dip"
android:layout_height="wrap_content"
android:gravity="right"
android:paddingRight="20dp"
android:paddingTop="20dp"
android:textStyle="italic"
android:textSize="12dp"
android:textColor="#00FF00" />
</LinearLayout>
</LinearLayout>
您可以首先使用length方法获取文件的大小。那么就这样做-
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE);
long fileSizeInBytes = videoCursor.getLong(videoColumnIndex)
// Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
long fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
long fileSizeInMB = fileSizeInKB / 1024;
您必须将字节除以1024以获得kb,将kb除以1024以获得mb,将mb除以1024以获得gb,依此类推 e、 g:
如果你能为1做这件事,只需在列表中循环并转换为allI我可以为none做这件事,我正在使用mediastore以字节为单位获取文件大小值:
205870
在你的代码中有什么意义?你应该在getView()方法中重复使用convertView,如果它不是null。nothing@selbie它只是一个随机数,无论我除以哪个数字,我总是得到相同的值。难道我不能使用MediaStore.Video.Media.DATA做类似的事情吗?你不是在下面的行-txtSize.setText(“大小(KB):”+(videoCursor.getString(videoColumnIndex/205870))中得到代码的大小吗;我得到的是以字节为单位的大小,但是将videocolumnindex除以1024得到的值是错误的。非常感谢,我也计算出来了。同时,我只需要使用一个长变量。谢谢你,你的回答是对的,所以我会接受的
long kilobytes = file.length() / 1024;
long megabytes = kilobytes / 1024;
long gigabytes = megabytes / 1024;