Gio.File.read_async

### Method

# Gio Fileread_async

#### Declaration

    void
    g_file_read_async (
      GFile* file,
      int io_priority,
      GCancellable* cancellable,
      GAsyncReadyCallback callback,
      gpointer user_data
    )

#### Description

Asynchronously opens `file` for reading.

For more details, see `g_file_read()` which is the synchronous version of this call.

When the operation is finished, `callback` will be called. You can then call `g_file_read_finish()` to get the result of the operation.

#### Parameters

`io_priority`

  Type: `int`

  The [I/O priority][io-priority] of the request.

`cancellable`

  Type: `GCancellable`

  Optional `GCancellable` object, `NULL` to ignore.

  The argument can be `NULL`.
  The data is owned by the caller of the method.

`callback`

  Type: `GAsyncReadyCallback`

  A `GAsyncReadyCallback` to call when the request is satisfied.

  The argument can be `NULL`.

`user_data`

  Type: `gpointer`

  The data to pass to callback function.

  The argument can be `NULL`.
  The data is owned by the caller of the method.