GDBusMessage: GIO Reference Manual

## GDBusMessage GDBusMessage — D-Bus Message |

## Functions

GDBusMessage * | g_dbus_message_new ()
GDBusMessage * | g_dbus_message_new_signal ()
GDBusMessage * | g_dbus_message_new_method_call ()
GDBusMessage * | g_dbus_message_new_method_reply ()
GDBusMessage * | g_dbus_message_new_method_error ()
GDBusMessage * | g_dbus_message_new_method_error_valist ()
GDBusMessage * | g_dbus_message_new_method_error_literal ()
gchar * | g_dbus_message_print ()
gboolean | g_dbus_message_get_locked ()
void | g_dbus_message_lock ()
GDBusMessage * | g_dbus_message_copy ()
GDBusMessageByteOrder | g_dbus_message_get_byte_order ()
void | g_dbus_message_set_byte_order ()
GDBusMessageType | g_dbus_message_get_message_type ()
void | g_dbus_message_set_message_type ()
guint32 | g_dbus_message_get_serial ()
void | g_dbus_message_set_serial ()
GDBusMessageFlags | g_dbus_message_get_flags ()
void | g_dbus_message_set_flags ()
GVariant * | g_dbus_message_get_body ()
void | g_dbus_message_set_body ()
GUnixFDList * | g_dbus_message_get_unix_fd_list ()
void | g_dbus_message_set_unix_fd_list ()
guint32 | g_dbus_message_get_num_unix_fds ()
void | g_dbus_message_set_num_unix_fds ()
guchar * | g_dbus_message_get_header_fields ()
GVariant * | g_dbus_message_get_header ()
void | g_dbus_message_set_header ()
const gchar * | g_dbus_message_get_destination ()
void | g_dbus_message_set_destination ()
const gchar * | g_dbus_message_get_error_name ()
void | g_dbus_message_set_error_name ()
const gchar * | g_dbus_message_get_interface ()
void | g_dbus_message_set_interface ()
const gchar * | g_dbus_message_get_member ()
void | g_dbus_message_set_member ()
const gchar * | g_dbus_message_get_path ()
void | g_dbus_message_set_path ()
guint32 | g_dbus_message_get_reply_serial ()
void | g_dbus_message_set_reply_serial ()
const gchar * | g_dbus_message_get_sender ()
void | g_dbus_message_set_sender ()
const gchar * | g_dbus_message_get_signature ()
void | g_dbus_message_set_signature ()
const gchar * | g_dbus_message_get_arg0 ()
guchar * | g_dbus_message_to_blob ()
gssize | g_dbus_message_bytes_needed ()
GDBusMessage * | g_dbus_message_new_from_blob ()
gboolean | g_dbus_message_to_gerror ()

## Properties

gboolean | locked | Read

## Types and Values

| GDBusMessage
enum | GDBusMessageType
enum | GDBusMessageFlags
enum | GDBusMessageHeaderField
enum | GDBusMessageByteOrder

## Object Hierarchy

        GEnum
        ├── GDBusMessageByteOrder
        ├── GDBusMessageHeaderField
        ╰── GDBusMessageType
        GFlags
        ╰── GDBusMessageFlags
        GObject
        ╰── GDBusMessage

## Includes

    #include <gio/gio.h>

## Description

A type for representing D-Bus messages that can be sent or received on a GDBusConnection.

## Functions

### g_dbus_message_new ()

    GDBusMessage *
    g_dbus_message_new (void);

Creates a new empty GDBusMessage.

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

Since: 2.26

### g_dbus_message_new_signal ()

    GDBusMessage *
    g_dbus_message_new_signal (const gchar *path,
                               const gchar *interface_,
                               const gchar *signal);

Creates a new GDBusMessage for a signal emission.

#### Parameters

path | A valid object path. |
interface_ | A valid D-Bus interface name. |
signal | A valid signal name. |

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

Since: 2.26

### g_dbus_message_new_method_call ()

    GDBusMessage *
    g_dbus_message_new_method_call (const gchar *name,
                                    const gchar *path,
                                    const gchar *interface_,
                                    const gchar *method);

Creates a new GDBusMessage for a method call.

#### Parameters

name | A valid D-Bus name or `NULL`. | [nullable]
path | A valid object path. |
interface_ | A valid D-Bus interface name or `NULL`. | [nullable]
method | A valid method name. |

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

Since: 2.26

### g_dbus_message_new_method_reply ()

    GDBusMessage *
    g_dbus_message_new_method_reply (GDBusMessage *method_call_message);

Creates a new GDBusMessage that is a reply to `method_call_message` .

#### Parameters

method_call_message | A message of type `G_DBUS_MESSAGE_TYPE_METHOD_CALL` to create a reply message to. |

#### Returns

GDBusMessage. Free with `g_object_unref()`.

[transfer full]

Since: 2.26

### g_dbus_message_new_method_error ()

    GDBusMessage *
    g_dbus_message_new_method_error (GDBusMessage *method_call_message,
                                     const gchar *error_name,
                                     const gchar *error_message_format,
                                     ...);

Creates a new GDBusMessage that is an error reply to `method_call_message` .

#### Parameters

method_call_message | A message of type `G_DBUS_MESSAGE_TYPE_METHOD_CALL` to create a reply message to. |
error_name | A valid D-Bus error name. |
error_message_format | The D-Bus error message in a `printf()` format. |
... | Arguments for `error_message_format` . |

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

[transfer full]

Since: 2.26

### g_dbus_message_new_method_error_valist ()

    GDBusMessage *
    g_dbus_message_new_method_error_valist
                                   (GDBusMessage *method_call_message,
                                    const gchar *error_name,
                                    const gchar *error_message_format,
                                    va_list var_args);

Like `g_dbus_message_new_method_error()` but intended for language bindings.

#### Parameters

method_call_message | A message of type `G_DBUS_MESSAGE_TYPE_METHOD_CALL` to create a reply message to. |
error_name | A valid D-Bus error name. |
error_message_format | The D-Bus error message in a `printf()` format. |
var_args | Arguments for `error_message_format` . |

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

[transfer full]

Since: 2.26

### g_dbus_message_new_method_error_literal ()

    GDBusMessage *
    g_dbus_message_new_method_error_literal
                                   (GDBusMessage *method_call_message,
                                    const gchar *error_name,
                                    const gchar *error_message);

Creates a new GDBusMessage that is an error reply to `method_call_message` .

#### Parameters

method_call_message | A message of type `G_DBUS_MESSAGE_TYPE_METHOD_CALL` to create a reply message to. |
error_name | A valid D-Bus error name. |
error_message | The D-Bus error message. |

#### Returns

A GDBusMessage. Free with `g_object_unref()`.

[transfer full]

Since: 2.26

### g_dbus_message_print ()

    gchar *
    g_dbus_message_print (GDBusMessage *message,
                          guint indent);

Produces a human-readable multi-line description of `message` .

The contents of the description has no ABI guarantees, the contents and formatting is subject to change at any time. Typical output looks something like this:

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    Type:    method-call
    Flags:   none
    Version: 0
    Serial:  4
    Headers:
      path -> objectpath '/org/gtk/GDBus/TestObject'
      interface -> 'org.gtk.GDBus.TestInterface'
      member -> 'GimmeStdout'
      destination -> ':1.146'
    Body: ()
    UNIX File Descriptors:
      (none)

or

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    Type:    method-return
    Flags:   no-reply-expected
    Version: 0
    Serial:  477
    Headers:
      reply-serial -> uint32 4
      destination -> ':1.159'
      sender -> ':1.146'
      num-unix-fds -> uint32 1
    Body: ()
    UNIX File Descriptors:
      fd 12: dev=0:10,mode=020620,ino=5,uid=500,gid=5,rdev=136:2,size=0,atime=1273085037,mtime=1273085851,ctime=1272982635

#### Parameters

message | A GDBusMessage. |
indent | Indentation level. |

#### Returns

A string that should be freed with `g_free()`.

[not nullable]

Since: 2.26

### g_dbus_message_get_locked ()

    gboolean
    g_dbus_message_get_locked (GDBusMessage *message);

Checks whether `message` is locked. To monitor changes to this value, conncet to the “notify” signal to listen for changes on the “locked” property.

#### Parameters

message | A GDBusMessage. |

#### Returns

`TRUE` if `message` is locked, `FALSE` otherwise.

Since: 2.26

### g_dbus_message_lock ()

    void
    g_dbus_message_lock (GDBusMessage *message);

If `message` is locked, does nothing. Otherwise locks the message.

#### Parameters

message | A GDBusMessage. |

Since: 2.26

### g_dbus_message_copy ()

    GDBusMessage *
    g_dbus_message_copy (GDBusMessage *message,
                         GError **error);

Copies `message` . The copy is a deep copy and the returned GDBusMessage is completely identical except that it is guaranteed to not be locked.

This operation can fail if e.g. `message` contains file descriptors and the per-process or system-wide open files limit is reached.

#### Parameters

message | A GDBusMessage. |
error | Return location for error or `NULL`. |

#### Returns

A new GDBusMessage or `NULL` if `error` is set. Free with `g_object_unref()`.

[transfer full]

Since: 2.26

### g_dbus_message_get_byte_order ()

    GDBusMessageByteOrder
    g_dbus_message_get_byte_order (GDBusMessage *message);

Gets the byte order of `message` .

#### Parameters

message | A GDBusMessage. |

#### Returns

The byte order.

### g_dbus_message_set_byte_order ()

    void
    g_dbus_message_set_byte_order (GDBusMessage *message,
                                   GDBusMessageByteOrder byte_order);

Sets the byte order of `message` .

#### Parameters

message | A GDBusMessage. |
byte_order | The byte order. |

### g_dbus_message_get_message_type ()

    GDBusMessageType
    g_dbus_message_get_message_type (GDBusMessage *message);

Gets the type of `message` .

#### Parameters

message | A GDBusMessage. |

#### Returns

A 8-bit unsigned integer (typically a value from the GDBusMessageType enumeration).

Since: 2.26

### g_dbus_message_set_message_type ()

    void
    g_dbus_message_set_message_type (GDBusMessage *message,
                                     GDBusMessageType type);

Sets `message` to be of `type` .

#### Parameters

message | A GDBusMessage. |
type | A 8-bit unsigned integer (typically a value from the GDBusMessageType enumeration). |

Since: 2.26

### g_dbus_message_get_serial ()

    guint32
    g_dbus_message_get_serial (GDBusMessage *message);

Gets the serial for `message` .

#### Parameters

message | A GDBusMessage. |

#### Returns

A guint32.

Since: 2.26

### g_dbus_message_set_serial ()

    void
    g_dbus_message_set_serial (GDBusMessage *message,
                               guint32 serial);

Sets the serial for `message` .

#### Parameters

message | A GDBusMessage. |
serial | A guint32. |

Since: 2.26

### g_dbus_message_get_flags ()

    GDBusMessageFlags
    g_dbus_message_get_flags (GDBusMessage *message);

Gets the flags for `message` .

#### Parameters

message | A GDBusMessage. |

#### Returns

Flags that are set (typically values from the GDBusMessageFlags enumeration bitwise ORed together).

Since: 2.26

### g_dbus_message_set_flags ()

    void
    g_dbus_message_set_flags (GDBusMessage *message,
                              GDBusMessageFlags flags);

Sets the flags to set on `message` .

#### Parameters

message | A GDBusMessage. |
flags | Flags for `message` that are set (typically values from the GDBusMessageFlags enumeration bitwise ORed together). |

Since: 2.26

### g_dbus_message_get_body ()

    GVariant *
    g_dbus_message_get_body (GDBusMessage *message);

Gets the body of a message.

#### Parameters

message | A GDBusMessage. |

#### Returns

A GVariant or `NULL` if the body is empty. Do not free, it is owned by `message` .

[nullable][transfer none]

Since: 2.26

### g_dbus_message_set_body ()

    void
    g_dbus_message_set_body (GDBusMessage *message,
                             GVariant *body);

Sets the body `message` . As a side-effect the `G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE` header field is set to the type string of `body` (or cleared if `body` is `NULL`).

If `body` is floating, `message` assumes ownership of `body` .

#### Parameters

message | A GDBusMessage. |
body | Either `NULL` or a GVariant that is a tuple. |

Since: 2.26

### g_dbus_message_get_unix_fd_list ()

    GUnixFDList *
    g_dbus_message_get_unix_fd_list (GDBusMessage *message);

Gets the UNIX file descriptors associated with `message` , if any.

This method is only available on UNIX.

The file descriptors normally correspond to `G_VARIANT_TYPE_HANDLE` values in the body of the message. For example, if `g_variant_get_handle()` returns 5, that is intended to be a reference to the file descriptor that can be accessed by `g_unix_fd_list_get (list, 5, ...)`.

#### Parameters

message | A GDBusMessage. |

#### Returns

A GUnixFDList or `NULL` if no file descriptors are associated. Do not free, this object is owned by `message` .

[nullable][transfer none]

Since: 2.26

### g_dbus_message_set_unix_fd_list ()

    void
    g_dbus_message_set_unix_fd_list (GDBusMessage *message,
                                     GUnixFDList *fd_list);

Sets the UNIX file descriptors associated with `message` . As a side-effect the `G_DBUS_MESSAGE_HEADER_FIELD_NUM_UNIX_FDS` header field is set to the number of fds in `fd_list` (or cleared if `fd_list` is `NULL`).

This method is only available on UNIX.

When designing D-Bus APIs that are intended to be interoperable, please note that non-GDBus implementations of D-Bus can usually only access file descriptors if they are referenced by a value of type `G_VARIANT_TYPE_HANDLE` in the body of the message.

#### Parameters

message | A GDBusMessage. |
fd_list | A GUnixFDList or `NULL`. | [nullable]

Since: 2.26

### g_dbus_message_get_num_unix_fds ()

    guint32
    g_dbus_message_get_num_unix_fds (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_NUM_UNIX_FDS` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

Since: 2.26

### g_dbus_message_set_num_unix_fds ()

    void
    g_dbus_message_set_num_unix_fds (GDBusMessage *message,
                                     guint32 value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_NUM_UNIX_FDS` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. |

Since: 2.26

### g_dbus_message_get_header_fields ()

    guchar *
    g_dbus_message_get_header_fields (GDBusMessage *message);

Gets an array of all header fields on `message` that are set.

#### Parameters

message | A GDBusMessage. |

#### Returns

An array of header fields terminated by `G_DBUS_MESSAGE_HEADER_FIELD_INVALID`. Each element is a guchar. Free with `g_free()`.

[array zero-terminated=1]

Since: 2.26

### g_dbus_message_get_header ()

    GVariant *
    g_dbus_message_get_header (GDBusMessage *message,
                               GDBusMessageHeaderField header_field);

Gets a header field on `message` .

The caller is responsible for checking the type of the returned GVariant matches what is expected.

#### Parameters

message | A GDBusMessage. |
header_field | A 8-bit unsigned integer (typically a value from the GDBusMessageHeaderField enumeration) |

#### Returns

A GVariant with the value if the header was found, `NULL` otherwise. Do not free, it is owned by `message` .

[transfer none][nullable]

Since: 2.26

### g_dbus_message_set_header ()

    void
    g_dbus_message_set_header (GDBusMessage *message,
                               GDBusMessageHeaderField header_field,
                               GVariant *value);

Sets a header field on `message` .

If `value` is floating, `message` assumes ownership of `value` .

#### Parameters

message | A GDBusMessage. |
header_field | A 8-bit unsigned integer (typically a value from the GDBusMessageHeaderField enumeration) |
value | A GVariant to set the header field or `NULL` to clear the header field. | [nullable]

Since: 2.26

### g_dbus_message_get_destination ()

    const gchar *
    g_dbus_message_get_destination (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_DESTINATION` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_destination ()

    void
    g_dbus_message_set_destination (GDBusMessage *message,
                                    const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_DESTINATION` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_error_name ()

    const gchar *
    g_dbus_message_get_error_name (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_ERROR_NAME` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_error_name ()

    void
    g_dbus_message_set_error_name (GDBusMessage *message,
                                   const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_ERROR_NAME` header field.

#### Parameters

message | A GDBusMessage. | [nullable]
value | The value to set. |

Since: 2.26

### g_dbus_message_get_interface ()

    const gchar *
    g_dbus_message_get_interface (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_INTERFACE` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_interface ()

    void
    g_dbus_message_set_interface (GDBusMessage *message,
                                  const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_INTERFACE` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_member ()

    const gchar *
    g_dbus_message_get_member (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_MEMBER` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_member ()

    void
    g_dbus_message_set_member (GDBusMessage *message,
                               const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_MEMBER` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_path ()

    const gchar *
    g_dbus_message_get_path (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_PATH` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_path ()

    void
    g_dbus_message_set_path (GDBusMessage *message,
                             const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_PATH` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_reply_serial ()

    guint32
    g_dbus_message_get_reply_serial (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_REPLY_SERIAL` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

Since: 2.26

### g_dbus_message_set_reply_serial ()

    void
    g_dbus_message_set_reply_serial (GDBusMessage *message,
                                     guint32 value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_REPLY_SERIAL` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. |

Since: 2.26

### g_dbus_message_get_sender ()

    const gchar *
    g_dbus_message_get_sender (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_SENDER` header field.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[nullable]

Since: 2.26

### g_dbus_message_set_sender ()

    void
    g_dbus_message_set_sender (GDBusMessage *message,
                               const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_SENDER` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_signature ()

    const gchar *
    g_dbus_message_get_signature (GDBusMessage *message);

Convenience getter for the `G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE` header field.

This will always be non-`NULL`, but may be an empty string.

#### Parameters

message | A GDBusMessage. |

#### Returns

The value.

[not nullable]

Since: 2.26

### g_dbus_message_set_signature ()

    void
    g_dbus_message_set_signature (GDBusMessage *message,
                                  const gchar *value);

Convenience setter for the `G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE` header field.

#### Parameters

message | A GDBusMessage. |
value | The value to set. | [nullable]

Since: 2.26

### g_dbus_message_get_arg0 ()

    const gchar *
    g_dbus_message_get_arg0 (GDBusMessage *message);

Convenience to get the first item in the body of `message` .

#### Parameters

message | A GDBusMessage. |

#### Returns

The string item or `NULL` if the first item in the body of `message` is not a string.

[nullable]

Since: 2.26

### g_dbus_message_to_blob ()

    guchar *
    g_dbus_message_to_blob (GDBusMessage *message,
                            gsize *out_size,
                            GDBusCapabilityFlags capabilities,
                            GError **error);

Serializes `message` to a blob. The byte order returned by `g_dbus_message_get_byte_order()` will be used.

#### Parameters

message | A GDBusMessage. |
out_size | Return location for size of generated blob. |
capabilities | A GDBusCapabilityFlags describing what protocol features are supported. |
error | Return location for error. |

#### Returns

A pointer to a valid binary D-Bus message of `out_size` bytes generated by `message` or `NULL` if `error` is set. Free with `g_free()`.

[array length=out_size][transfer full]

Since: 2.26

### g_dbus_message_bytes_needed ()

    gssize
    g_dbus_message_bytes_needed (guchar *blob,
                                 gsize blob_len,
                                 GError **error);

Utility function to calculate how many bytes are needed to completely deserialize the D-Bus message stored at `blob` .

#### Parameters

blob | A blob representing a binary D-Bus message. | [array length=blob_len][element-type guint8]
blob_len | The length of `blob` (must be at least 16). |
error | Return location for error or `NULL`. |

#### Returns

Number of bytes needed or -1 if `error` is set (e.g. if `blob` contains invalid data or not enough data is available to determine the size).

Since: 2.26

### g_dbus_message_new_from_blob ()

    GDBusMessage *
    g_dbus_message_new_from_blob (guchar *blob,
                                  gsize blob_len,
                                  GDBusCapabilityFlags capabilities,
                                  GError **error);

Creates a new GDBusMessage from the data stored at `blob` . The byte order that the message was in can be retrieved using `g_dbus_message_get_byte_order()`.

If the `blob` cannot be parsed, contains invalid fields, or contains invalid headers, `G_IO_ERROR_INVALID_ARGUMENT` will be returned.

#### Parameters

blob | A blob representing a binary D-Bus message. | [array length=blob_len][element-type guint8]
blob_len | The length of `blob` . |
capabilities | A GDBusCapabilityFlags describing what protocol features are supported. |
error | Return location for error or `NULL`. |

#### Returns

A new GDBusMessage or `NULL` if `error` is set. Free with `g_object_unref()`.

Since: 2.26

### g_dbus_message_to_gerror ()

    gboolean
    g_dbus_message_to_gerror (GDBusMessage *message,
                              GError **error);

If `message` is not of type `G_DBUS_MESSAGE_TYPE_ERROR` does nothing and returns `FALSE`.

Otherwise this method encodes the error in `message` as a GError using `g_dbus_error_set_dbus_error()` using the information in the `G_DBUS_MESSAGE_HEADER_FIELD_ERROR_NAME` header field of `message` as well as the first string item in `message` 's body.

#### Parameters

message | A GDBusMessage. |
error | The GError to set. |

#### Returns

`TRUE` if `error` was set, `FALSE` otherwise.

Since: 2.26

## Types and Values

### GDBusMessage

    typedef struct _GDBusMessage GDBusMessage;

The GDBusMessage structure contains only private data and should only be accessed using the provided API.

Since: 2.26

### enum GDBusMessageType

Message types used in GDBusMessage.

#### Members

G_DBUS_MESSAGE_TYPE_INVALID | Message is of invalid type. |
G_DBUS_MESSAGE_TYPE_METHOD_CALL | Method call. |
G_DBUS_MESSAGE_TYPE_METHOD_RETURN | Method reply. |
G_DBUS_MESSAGE_TYPE_ERROR | Error reply. |
G_DBUS_MESSAGE_TYPE_SIGNAL | Signal emission. |

Since: 2.26

### enum GDBusMessageFlags

Message flags used in GDBusMessage.

#### Members

G_DBUS_MESSAGE_FLAGS_NONE | No flags set. |
G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED | A reply is not expected. |
G_DBUS_MESSAGE_FLAGS_NO_AUTO_START | The bus must not launch an owner for the destination name in response to this message. |
G_DBUS_MESSAGE_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION | If set on a method call, this flag means that the caller is prepared to wait for interactive authorization. Since 2.46. |

Since: 2.26

### enum GDBusMessageHeaderField

Header fields used in GDBusMessage.

#### Members

G_DBUS_MESSAGE_HEADER_FIELD_INVALID | Not a valid header field. |
G_DBUS_MESSAGE_HEADER_FIELD_PATH | The object path. |
G_DBUS_MESSAGE_HEADER_FIELD_INTERFACE | The interface name. |
G_DBUS_MESSAGE_HEADER_FIELD_MEMBER | The method or signal name. |
G_DBUS_MESSAGE_HEADER_FIELD_ERROR_NAME | The name of the error that occurred. |
G_DBUS_MESSAGE_HEADER_FIELD_REPLY_SERIAL | The serial number the message is a reply to. |
G_DBUS_MESSAGE_HEADER_FIELD_DESTINATION | The name the message is intended for. |
G_DBUS_MESSAGE_HEADER_FIELD_SENDER | Unique name of the sender of the message (filled in by the bus). |
G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE | The signature of the message body. |
G_DBUS_MESSAGE_HEADER_FIELD_NUM_UNIX_FDS | The number of UNIX file descriptors that accompany the message. |

Since: 2.26

### enum GDBusMessageByteOrder

Enumeration used to describe the byte order of a D-Bus message.

#### Members

G_DBUS_MESSAGE_BYTE_ORDER_BIG_ENDIAN | The byte order is big endian. |
G_DBUS_MESSAGE_BYTE_ORDER_LITTLE_ENDIAN | The byte order is little endian. |

Since: 2.26

## Property Details

### The `“locked”` property

      “locked”                   gboolean

Whether the message is locked.

Owner: GDBusMessage

Flags: Read

Default value: FALSE