f9/sdk/dart/package-fuchsia_vfs_vfs/PseudoFile/PseudoFile.readWriteStr.md

# PseudoFile.readWriteStr constructor




    *[<Null safety>](https://dart.dev/null-safety)*



PseudoFile.readWriteStr(int _capacity, [ReadFnStr](../../package-fuchsia_vfs_vfs/ReadFnStr.md) rfn, [WriteFnStr](../../package-fuchsia_vfs_vfs/WriteFnStr.md) wfn)


<p>See <code>#readWrite()</code>.  Wraps the read callback, allowing it to return a <code>String</code> instead of a
<code>Uint8List</code>.  Wraps the write callback, only allowing valid UTF-8 content to be written into
the file.  Written bytes are converted into a string instance, and the passed to the handler.
In every other aspect behaves just like <code>#readWrite()</code>.</p>



## Implementation

```dart
PseudoFile.readWriteStr(this._capacity, ReadFnStr rfn, WriteFnStr wfn)
    : assert(_capacity > 0),
      assert(rfn != null),
      assert(wfn != null) {
  _readFn = _getReadFn(rfn);
  _writeFn = _getWriteFn(wfn);
}
```