Question

我使用以下代码将图像写入android中的外部存储：

File root = android.os.Environment.getExternalStorageDirectory(); 
File dir = new File (root.getAbsolutePath() + "/download");
dir.mkdirs(); 
fileName = "image_2.jpeg";
File file = new File(dir, fileName);

try {
    FileOutputStream outStream = new FileOutputStream(file);
    Bitmap bitmap = BitmapFactory.decodeFile("android.resource://com.mypackage.com/drawable/image_1");
    bitmap.compress(Bitmap.CompressFormat.JPEG, 70, outStream);
    outStream.flush();
    outStream.close();
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}

此代码用于从drawable文件夹中读取image_1.jpg，然后使用image_2.jpeg名称将其写入外部存储中的下载文件夹。（在外部存储中创建下载文件夹，在该文件夹中创建image_2.jpeg名称的文件）。此代码将生成（（强制关闭））。创建了下载文件夹，并且还创建了image_2.jpeg，但图像image_2.jpeg已损坏。

Answer 1

可绘制文件夹中的这些图像可以通过BitmapFactory访问，您可以将位图保存为PNG或JPG。

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
File sd = Environment.getExternalStorageDirectory();
String fileName = "test.png";
File dest = new File(sd, fileName);
try {
    FileOutputStream out;
    out = new FileOutputStream(dest);
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
    out.flush();
    out.close();
} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

不要忘记添加android.permission.WRITE_EXTERNAL_STORAGE权限。

对于其他类型的图像，我认为将它们放入资源文件夹是一种更好的方法。

There is a sample here.

Answer 2

我对此代码做了同样的事情。试试这段代码：

String[] sampleImagesName = { "image2" };
int[] sampleImages = { R.drawable.image1};
File file;
if (Environment.getExternalStorageState().equals(
    Environment.MEDIA_MOUNTED)) {
    file = new File(Environment.getExternalStorageDirectory()
        .getAbsolutePath() + "/download");
    if (!file.exists()) {
        file.mkdirs();
        SaveSampleToSD();
    }
}
private void SaveSampleToSD() {
        String path = Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/download";

        for (int i = 0; i < sampleImages.length; i++) {
            try {
                File f = new File(path + "/", sampleImagesName[i] + ".jpg");
                Bitmap bm = BitmapFactory.decodeResource(getResources(),
                        sampleImages[i]);
                FileOutputStream out = new FileOutputStream(f);
                bm.compress(Bitmap.CompressFormat.JPEG, 100, out);

                out.flush();
                out.close();

                Log.e("ImageSaved---------", "saved");
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }

在android中将图像写入外部存储器

2 个答案: