我正在尝试将图像（jpg或png）从res / raw或assets文件夹保存到SD卡位置（/ sdcard / DCIM /）。
我一直在关注一个可以将图像从URL保存到SD卡Root的教程，但是我已经到处查看能够从res / raw或资源文件夹保存到sd卡上的不同位置/ SD卡/ DCIM /
这是代码，任何人都可以告诉我如何从上面做到这一点吗？
public class home extends Activity {
private File file;
private String imgNumber;
private Button btnDownload;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnDownload=(Button)findViewById(R.id.btnDownload);
btnDownload.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
btnDownload.setText("Download is in Progress.");
String savedFilePath=Download("http://www.domain.com/android1.png");
Toast.makeText(getApplicationContext(), "File is Saved in "+savedFilePath, 1000).show();
if(savedFilePath!=null)
{
btnDownload.setText("Download Completed.");
}
}
});
}
public String Download(String Url)
{
String filepath=null;
try {
//set the download URL, a url that points to a file on the internet
//this is the file to be downloaded
URL url = new URL(Url);
//create the new connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//and connect!
urlConnection.connect();
//set the path where we want to save the file
//in this case, going to save it on the root directory of the
//sd card.
File SDCardRoot = Environment.getExternalStorageDirectory();
//create a new file, specifying the path, and the filename
//which we want to save the file as.
String filename= "download_"+System.currentTimeMillis()+".png"; // you can download to any type of file ex:.jpeg (image) ,.txt(text file),.mp3 (audio file)
Log.i("Local filename:",""+filename);
file = new File(SDCardRoot,filename);
if(file.createNewFile())
{
file.createNewFile();
}
//this will be used to write the downloaded data into the file we created
FileOutputStream fileOutput = new FileOutputStream(file);
//this will be used in reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
//this is the total size of the file
int totalSize = urlConnection.getContentLength();
//variable to store total downloaded bytes
int downloadedSize = 0;
//create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0; //used to store a temporary size of the buffer
//now, read through the input buffer and write the contents to the file
while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
//add the data in the buffer to the file in the file output stream (the file on the sd card
fileOutput.write(buffer, 0, bufferLength);
//add up the size so we know how much is downloaded
downloadedSize += bufferLength;
//this is where you would do something to report the prgress, like this maybe
Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
btnDownload.setText("download Status:"+downloadedSize+" / "+totalSize);
}
//close the output stream when done
fileOutput.close();
if(downloadedSize==totalSize) filepath=file.getPath();
//catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
filepath=null;
btnDownload.setText("Internet Connection Failed.\n"+e.getMessage());
e.printStackTrace();
}
Log.i("filepath:"," "+filepath) ;
return filepath;
}
}
答案 0 :(得分：2)
经过测试和运作的代码：
为了将资源（image1.png）中的图像复制到SD卡上的Pictures目录（image1.jpg）中的图像文件，您可以尝试以下方法（在SD上保存图像所需的android.permission.WRITE_EXTERNAL_STORAGE）卡）。已发送ACTION_MEDIA_SCANNER_SCAN_FILE广播，以便将新图片传递到媒体扫描程序，因此尽快在媒体库中显示。
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import android.net.Uri;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.Button;
import android.os.Bundle;
import android.os.Environment;
import android.view.View
public class MainScreen extends Activity
{
private Button btnDownload;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnDownload=(Button)findViewById(R.id.SaveButton1);
btnDownload.setOnClickListener(
new Button.OnClickListener() {
@Override
public void onClick(View v) {
String newPicture = saveToSDCard(R.drawable.image1, "image1.jpg");
startMediaScanner(newPicture);
}
}
);
}
private String saveToSDCard(int resourceID, String finalName)
{
StringBuffer createdFile = new StringBuffer();
Bitmap resourceImage = BitmapFactory.decodeResource(this.getResources(), resourceID);
File externalStorageFile = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), finalName);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
resourceImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
byte b[] = bytes.toByteArray();
try
{
externalStorageFile.createNewFile();
OutputStream filoutputStream = new FileOutputStream(externalStorageFile);
filoutputStream.write(b);
filoutputStream.flush();
filoutputStream.close();
createdFile.append(externalStorageFile.getAbsolutePath());
}
catch (IOException e)
{
}
return createdFile.toString();
}
private void startMediaScanner(String addedPicture)
{
sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://"+ addedPicture)));
}
}
答案 1 :(得分：2)
InputStream is = context.getAssets().open(fileName);
OutputStream os = new FileOutputStream(Environment.getExternalStorageDirectory() + File.separator + fileName);
BufferedInputStream bis = new BufferedInputStream(is);
BufferedOutputStream bos = new BufferedOutputStream(os);
byte[] buf = new byte[1024];
int n = 0;
int o = 0;
while ((n = bis.read(buf, o, buf.length)) != 0) {
bos.write(buf, 0, n);
}
bis.close();
bos.close();