Store Bitmap image to SD Card in Android

问题

I am facing some strange problem with my android code, I have an image in Bitmap variable and want to save that file to SD card. I code as follow,

Bitmap IMAGE // Loaded from internet servers.;
try {
    File _sdCard = Environment.getExternalStorageDirectory();
    File _picDir  = new File(_sdCard, "MyDirectory");
    _picDir.mkdirs();

    File _picFile = new File(_picDir,  "MyImage.jpg");
    FileOutputStream _fos = new FileOutputStream(_picFile);
    IMAGE.compress(Bitmap.CompressFormat.JPEG, 100, _fos);
    _fos.flush();
    _fos.close();
    Toast.makeText(this, "Image Downloaded", 7000).show();
} catch (Exception ex) {
    ex.printStackTrace();
    Toast.makeText(this, ex.getMessage(), 7000).show();
}

I am using Sony Experia Arc as my testing device, when the phone is connected to my computer, the code works nice, it stores image and also displays in gallery. But when I disconnect phone from my computer and test the app, it doesn't save picture and doesn't show any exception.

回答1:

use this function

 void saveImage() {

    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/saved_images");

    String fname = "Image.jpg";
    File file = new File (myDir, fname);
    if (file.exists ()) file.delete (); 
    try {
           FileOutputStream out = new FileOutputStream(file);
           myBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
           out.flush();
           out.close();

    } catch (Exception e) {
           e.printStackTrace();
    }
}

Check this answer will give more details Android saving file to external storage

回答2:

ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        thumbnail.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        //4
        File file = new File(Environment.getExternalStorageDirectory()+File.separator +        "image.jpg");
        try {
            file.createNewFile();
            FileOutputStream fo = new FileOutputStream(file);
            //5
            fo.write(bytes.toByteArray());
            fo.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

回答3:

**This Code Cover the Following Topics**

1. Save a bitmap Image on sdcard a jpeg
2. Create a folder on sdcard
3. Create every file Separate name
4. Every file save with date and time
5. Resize the image in very small size
6. Best thing image Quality fine not effected from Resizing


The following method is used to create an image file using the bitmap

public void createImageFromBitmap(Bitmap bmp) {

    FileOutputStream fileOutputStream = null;
    try {

        // create a File object for the parent directory
        File wallpaperDirectory = new File("/sdcard/Capture/");
        // have the object build the directory structure, if needed.
        wallpaperDirectory.mkdirs();

        //Capture is folder name and file name with date and time
        fileOutputStream = new FileOutputStream(String.format(
                "/sdcard/Capture/%d.jpg",
                System.currentTimeMillis()));

        // Here we Resize the Image ...
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        bmp.compress(Bitmap.CompressFormat.JPEG, 100,
                byteArrayOutputStream); // bm is the bitmap object
        byte[] bsResized = byteArrayOutputStream.toByteArray();


        fileOutputStream.write(bsResized);
        fileOutputStream.close();


    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
    }
}


   and add this in manifest

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

来源：https://stackoverflow.com/questions/7844746/store-bitmap-image-to-sd-card-in-android

标签

android

bitmap

sd-card