The
qtgrpcgen
tool can be used to generate Qt GRPC service classes from a protobuf schema. The tool is provided by the CMake
Qt6::GrpcTools
package. It works as an extension to Google's
protoc
工具。
find_package(Qt6 COMPONENTS GrpcTools REQUIRED)
Qt 提供的 CMake 函数易于使用
qtgrpcgen
tool. When using CMake as a build tool, it's better to utilize the
Qt CMake API
. For build systems other than CMake, you can adjust the commands outlined in the
Running qtgrpcgen manually
.
注意： There is no explicit support for building gRPC ™ and Protobuf applications using the Qt GRPC module with qmake .
The following CMake commands integrate a gRPC service into a Qt project.
| Generates Qt-based C++ services using a protobuf schema |
通常
qtgrpcgen
would be invoked through CMake using the
qt_add_grpc
macro, as shown in the following example:
cmake_minimum_required(VERSION 3.16...3.22)
project(MyProject)
find_package(Qt6 REQUIRED COMPONENTS Protobuf Grpc)
qt_standard_project_setup()
qt_add_executable(MyApp main.cpp)
qt_add_protobuf(MyApp
PROTO_FILES
path/to/messages.proto
)
qt_add_grpc(MyApp CLIENT
PROTO_FILES
path/to/service.proto
)
target_link_libraries(MyApp PRIVATE Qt6::Protobuf Qt6::Grpc)
The example above calls the
qt_add_grpc()
CMake function to start Qt GRPC code generation for
service
sections within the provided protobuf schema.
注意：
If the protobuf schema also contains
message
definitions, the
qt_add_protobuf()
CMake function should also be called to start Qt Protobuf code generation.
Since we reuse the executable target, all generated files will be appended to the target, and the include directories will be updated accordingly.
qtgrpcgen
manually
protoc --plugin=protoc-gen-qtgrpc=<path/to/bin/>qtgrpcgen \
--qtgrpc_out="[<options>:]<output_dir>" \
[--qtgrpc_opt="<options>"] \
[-I/extra/proto/include/path] \
<protofile>.proto
The
options
argument is a semicolon-separated list of
选项
. It can be passed by adding
options
到
--qtgrpc_out
argument, separated by a colon, or through a separate argument,
--qtgrpc_opt
. You also can pass the corresponding keys as the
QT_GRPC_OPTIONS
environment variable. Keys must be presented as a semicolon-separated list:
export QT_GRPC_OPTIONS="COPY_COMMENTS;GENERATE_PACKAGE_SUBFOLDERS"
The generator supports options that can be provided to tune generation. Options have direct aliases in the qt_add_grpc function. The following options are supported:
COPY_COMMENTS
copies comments from the
.proto
files into the generated code.
GENERATE_PACKAGE_SUBFOLDERS
uses the package name specifier from the
.proto
files to create the folder structure for the generated files. For example, if the package is defined as:
package io.qt.test
, the generated files will be placed in
OUTPUT_DIRECTORY/io/qt/test/
.
EXPORT_MACRO
defines the base name for the export macro used in the generated code. The final macro name is constructed as
QPB_<EXPORT_MACRO>_EXPORT
. If this option is not set, no export macro is generated.
Since Qt 6.8, the following format is supported:
EXPORT_MACRO=macro_name[:macro_output_file[:<true|false>]]
. This format allows you to specify the name of the header file containing the export macro and explicitly control whether it is generated.
注意： 若 <macro_output_file> is not provided, the option defaults to the previous syntax.
QML
enables the generation of a QML client for the
gRPC
service.