Question

我正在从gallery中选择一个图像。我想用kb或mb以编程方式确定图像的大小。这就是我写的：

public String calculateFileSize(Uri filepath)
{
    //String filepathstr=filepath.toString();
    File file = new File(filepath.getPath());

    // Get length of file in bytes
    long fileSizeInBytes = file.length();
    // 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;

    String calString=Long.toString(fileSizeInMB);
    return calString;
}

从图库中选择的图像的uri完美无缺。但是fileSizeInBytes的值为零。我在onActivityResult上调用此方法后，从图库中选择图像。我看到了以前问过同样的问题。但没有一个对我有用。有什么解决方案吗？

Answer 1

更改

public String calculateFileSize(Uri filepath)
{
  //String filepathstr=filepath.toString();
  File file = new File(filepath.getPath());

  long fileSizeInKB = fileSizeInBytes / 1024;
  // Convert the KB to MegaBytes (1 MB = 1024 KBytes)
  long fileSizeInMB = fileSizeInKB / 1024;

  String calString=Long.toString(fileSizeInMB);

到

public String calculateFileSize(String filepath)
{
  //String filepathstr=filepath.toString();
  File file = new File(filepath);

  float fileSizeInKB = fileSizeInBytes / 1024;
  // Convert the KB to MegaBytes (1 MB = 1024 KBytes)
  float fileSizeInMB = fileSizeInKB / 1024;

  String calString=Float.toString(fileSizeInMB);

当您使用long时，它会截断.之后的所有数字。因此，如果您的尺寸小于1MB，您将获得0。

因此，请使用float代替long

Answer 2

试试这个，它会对你有用

private void getImageSize(Uri choosen) throws IOException {
        Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), choosen);

        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
        byte[] imageInByte = stream.toByteArray();
        long lengthbmp = imageInByte.length;

        Toast.makeText(getApplicationContext(),Long.toString(lengthbmp),Toast.LENGTH_SHORT).show();

    }

结果

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch(requestCode) {
            case SELECT_PHOTO:
                if(resultCode == RESULT_OK){
                    Uri selectedImage = data.getData();

                    if(selectedImage !=null){

                        img.setImageURI(selectedImage);

                        try {
                            getImageSize(choosenPhoto);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                        //txt1.setText("Initial size: " +getImageSize(choosenPhoto)+ " Kb");
                    }
                }
        }
    }

Answer 3

使用uri.getLastPathSegment()代替uri.getPath()

public static float getImageSize(Uri uri) {

    File file = new File(uri.getLastPathSegment());
    return file.length(); // returns size in bytes
}

重要

以上代码仅适用于从图库中选取的图像；不适用于文件管理器，因为它无法识别URI方案

下面的方法在两种情况下都可以使用

public static float getImageSize(Context context, Uri uri) {
    Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
    if (cursor != null) {
        int sizeIndex = cursor.getColumnIndex(OpenableColumns.SIZE);
        cursor.moveToFirst();
        float imageSize = cursor.getLong(sizeIndex);
        cursor.close();
        return imageSize; // returns size in bytes
    }
    return 0;
}

要从字节变为千字节>>> / 1024f

要从字节变为兆字节>>> /（1024f * 1024f）

Answer 4

这是一种计算从图库中选择的图像尺寸的方法。您可以在onActivityResult中传递从意图中获得的Uri：

public static double getImageSizeFromUriInMegaByte(Context context, Uri uri) {
    String scheme = uri.getScheme();
    double dataSize = 0;
    if (scheme.equals(ContentResolver.SCHEME_CONTENT)) {
        try {
            InputStream fileInputStream = context.getContentResolver().openInputStream(uri);
            if (fileInputStream != null) {
                dataSize = fileInputStream.available();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    } else if (scheme.equals(ContentResolver.SCHEME_FILE)) {
        String path = uri.getPath();
        File file = null;
        try {
            file = new File(path);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (file != null) {
            dataSize = file.length();
        }
    }
    return dataSize / (1024 * 1024);
}

Answer 5

private boolean validImageSize() {
        try {
            if (bitmapPhoto!=null){
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                bitmapPhoto.compress(Bitmap.CompressFormat.PNG, 100, stream);
                byte[] imageInByte = stream.toByteArray();


                // Get length of file in bytes
                float imageSizeInBytes = imageInByte.length;
                // Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
                float imageSizeInKB = imageSizeInBytes / 1024;
                // Convert the KB to MegaBytes (1 MB = 1024 KBytes)
                float imageSizeInMB = imageSizeInKB / 1024;
                return imageSizeInMB <= 1;
            }else {
                return true;
            }
        }catch (Exception e){
            e.printStackTrace();
            return true;

        }

    }

Answer 6

试试这个，它会从新的安卓和旧版本的 uri 返回给你

fun getFileFromUri(uri: Uri): File? {
if (uri.path == null) {
    return null
}
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (uri.path!!.contains("/document/image:")) {
    databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
    selection = "_id=?"
    selectionArgs = arrayOf(DocumentsContract.getDocumentId(uri).split(":")[1])
} else {
    databaseUri = uri
    selection = null
    selectionArgs = null
}
try {
    val column = "_data"
    val projection = arrayOf(column)
    val cursor = context.contentResolver.query(
        databaseUri,
        projection,
        selection,
        selectionArgs,
        null
    )
    cursor?.let {
        if (it.moveToFirst()) {
            val columnIndex = cursor.getColumnIndexOrThrow(column)
            realPath = cursor.getString(columnIndex)
        }
        cursor.close()
    }
} catch (e: Exception) {
    Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = if (realPath.isNotEmpty()) realPath else {
    when {
        uri.path!!.contains("/document/raw:") -> uri.path!!.replace(
            "/document/raw:",
            ""
        )
        uri.path!!.contains("/document/primary:") -> uri.path!!.replace(
            "/document/primary:",
            "/storage/emulated/0/"
        )
        else -> return null
    }
}
return File(path)}

然后你可以使用它来获取文件大小

val file = getFileFromUri(your_uri)
val file_size = Integer.parseInt(String.valueOf(file.length()/1024))

以编程方式获取从库中选择的图像大小（以kb或mb为单位）

6 个答案: