Question

我的Android代码遇到了一些奇怪的问题，我在Bitmap变量中有一个图像，并希望将该文件保存到SD卡。我编码如下，

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();
}

我使用Sony Experia Arc作为我的测试设备，当手机连接到我的电脑时，代码效果很好，它存储图像并显示在图库中。但是，当我从手机上断开手机并测试应用程序时，它不会保存图片，也不会显示任何异常。

Answer 1

使用此功能

 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();
    }
}

检查此答案将提供更多详细信息Android saving file to external storage

Answer 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();
        }

Answer 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" />

将位图图像存储到Android中的SD卡

3 个答案: