環境
系統：win10 x64
QGIS版本：V3.12.3
VS版本：VS2015
安裝osgeo4w
1、osgeo4w地址
32位：http://download.osgeo.org/osgeo4w/osgeo4w-setup-x86.exe
64位：http://download.osgeo.org/osgeo4w/osgeo4w-setup-x86_64.exe
2、選擇 Advanced Install，點擊 NEXT。
3、選擇 Install from Internet，點擊 NEXT。
4、安裝路徑選擇。這裏選擇 C:\OSGEO4W （默認）。
5、 下載安裝包保存路徑。建議新建QGIS文件保存，路徑自定義。
6、網絡連接方式，選擇 Direct Connection，點擊 NEXT。
7、下載地址選擇，這裏選擇 http://www.nobit.de，點擊 NEXT。這裏可以隨便選，下載那個快選哪個。注意：下載速度時快時慢，一般早晨最快。（我的位置在福州）
8、選擇安裝包頁面，查找 qgis，彈出下列目錄。點開 Libs 節點，選擇 下列 安裝包。（已用紅框圈出）
9、這個對話框比較隱蔽，大家很容易忽視。Unmet Dependencies Found（發現未滿足的依賴關係）。
安裝程序檢測安裝依賴關係，增加了許多基礎安裝包，如下表所示。
avce00 (2.0.0-1)
The AVCE00 commandline utilities for Arc/Info E00 conversion
Required by: grass, msys-grass
boost (1.56.0-2)
The Boost library.
Required by: libkml
cairo (1.12.14-1)
Cairo library
Required by: grass
curl (7.67.0-1)
The CURL HTTP/FTP library and commandline utility.
Required by: gdal, netcdf, gdal111dll, gdal18dll
curl-ca-bundle (20191119-1)
CURL CA certificates
Required by: curl
exiv2 (0.26-1)
Image metadata library
Required by: qgis, qgis-ltr
expat (2.0.1-1)
The Expat XML Parser library
Required by: gdal, ogdi, libkml, gpsbabel, exiv2, gdal111dll, gdal18dll
fftw (3.2-1)
Fast Fourier transformation library
Required by: grass, msys-grass
freetype-mingw (2.3.7-1)
FreeType library (MinGW built).
Required by: msys-grass
freexl (1.0.2-1)
The FreeXL library for accessing Excel (.xls) spreadsheet.
Required by: gdal, spatialite, gdal111dll
gdal (3.0.4-2)
The GDAL/OGR library and commandline tools
Required by: qgis-common, grass, python3-gdal, gpsbabel, msys-grass, liblas, qgis-ltr-common
gdal111dll (1.11.3-1)
The GDAL/OGR 1.11 DLL (backward compability package)
Required by: grass6
gdal18dll (1.8.1-0)
The GDAL/OGR 1.8 DLL (backward compability package)
Required by: liblas
geos (3.8.1-1)
The GEOS geometry library
Required by: qgis-common, gdal, spatialite, liblwgeom, gdal111dll, qgis-ltr-common, gdal18dll
gpsbabel (1.4.4-1)
GPS file conversion plus transfer to/from GPS units
Required by: qgis, grass, qgis-ltr, msys-grass
grass (7.8.3-1)
GRASS GIS
Required by: qgis-grass-plugin7, qgis-ltr-grass-plugin7
grass6 (6.4.4-1)
GRASS GIS - old stable release
Required by: qgis-grass-plugin
gs (9.07-3)
Ghostscript
Required by: grass, msys-grass
gsl-libs (1.12-1)
GNU Scientific Library (GSL)
Required by: qgis-common, qgis-ltr-common
hdf4 (4.2.14-1)
The HDF4 library for reading and writing HDF4 format
Required by: gdal, gdal111dll, gdal18dll
hdf5 (1.10.4-1)
The HDF5 library for reading and writing HDF5 format
Required by: netcdf, gdal111dll, gdal18dll
iconv (1.9.1-1)
Codepage translation Library
Required by: qgis-common, spatialite, grass, freexl, msys-grass, gdal111dll, cairo, qgis-ltr-common
iconv-vc14 (1.15-1)
Codepage translation Library
Required by: gdal
icu-libs (56.1-3)
ICU (library)
Required by: qtwebkit-qt5-libs
laszip (2.2.0-1)
The LASzip compression library
Required by: liblas
libcairo (1.10.2-1)
Cairo library and dependencies
Required by: msys-grass
libgeotiff (1.4.2-1)
The Libgeotiff library, commandline tools and supporting tables.
Required by: gdal111dll, liblas, gdal18dll
libintl (0.14.4-2)
libintl
Required by: grass6, msys-grass
libjpeg (6b-5)
A library for manipulating JPEG image format files (runtime)
Required by: gdal111dll, libtiff, gdal18dll
libjpeg12 (6b-3)
A library for manipulating 12bit JPEG image format files
Required by: libtiff
libkml (1.3.0-1)
LibKML
Required by: gdal
liblas (1.7.0-1)
The libLAS commandline utilities
Required by: grass
liblwgeom (3.0.0-2)
liblwgeom
Required by: spatialite
libmysql (6.1.9-1)
MySQL Client Library.
Required by: gdal, gdal111dll, gdal18dll
libpng (1.2.34-1)
the official PNG reference library
Required by: grass, msys-grass
libpng-vc14 (1.6.29-1)
the official PNG reference library
Required by: gdal, openjpeg
libpq (11.5-1)
The libpq library for accessing PostgreSQL + psql commandline client
Required by: qgis-common, gdal, gdal111dll, qgis-ltr-common, gdal18dll
libspatialindex (1.9.0-1)
The libspatialindex library
Required by: qgis-common, qgis-ltr-common
libtiff (4.0.8-1)
A library for manipulating TIFF format image files (runtime)
Required by: grass, openjpeg, msys-grass, gdal111dll, liblas, libgeotiff, gdal18dll
libxml2 (2.9.1-1)
An XML read/write library
Required by: spatialite, cairo
libzip-libs (1.2.0-2)
libzip (runtime library)
Required by: qgis-common, qgis-ltr-common
msvc2015 (1.0.0-1)
msvc2015
Required by: spatialite
msvcrt (1.0.3-1)
Microsoft Visual C/C++ Runtimes
Required by: qgis-common, qgis-grass-plugin, qgis-grass-plugin7, opencl, grass, msvcrt2015, shell, openjpeg, libkml, msys, msys-grass, setup, boost, laszip
msvcrt2008 (1.0-1)
Microsoft Visual C/C++ 2008 Runtimes
Required by: msvcrt, xerces-c-vc9, python-core
msvcrt2010 (1.0-1)
Microsoft Visual C/C++ 2010 Runtimes
Required by: msvcrt
msvcrt2013 (1.0-1)
Microsoft Visual C/C++ 2013 Runtimes
Required by: grass
msvcrt2015 (1.0-1)
Microsoft Visual C/C++ 2015 Runtimes
Required by: qgis-ltr-grass-plugin7, qt5-libs, libpq, proj, geos, gdal, libspatialindex, libzip-libs, grass, openssl, sqlite3, libpng-vc14, curl, libmysql, xerces-c, hdf4, ogdi, iconv-vc14, xz, zstd, python3-core, liblwgeom, msvc2015, exiv2, libtiff, qgis-ltr-common, hdf5, szip
msys (1.0.18-7)
Minimal SYStem
Required by: grass6
msys-grass (1-8)
MSYS - GRASS GIS dependencies
Required by: grass6
netcdf (4.7.3-1)
The NetCDF library and commands for reading and writing NetCDF format
Required by: gdal, gdal111dll, gdal18dll
ogdi (4.1.0-1)
OGDI data access library (mainly for VPF reading)
Required by: gdal, gdal111dll, gdal18dll
opencl (2.0.10-5)
KhronosGroup OpenCL runtime
Required by: qgis-common, qgis-ltr-common
openjpeg (2.3.0-1)
OpenJPEG
Required by: gdal, gdal111dll
openssl (1.1.1d-2)
OpenSSL Cryptography (Runtime)
Required by: qt5-libs, libpq, curl, python3-core
openssl10 (1.0.2j-1)
OpenSSL 1.0 Cryptography (Runtime)
Required by: libzip-libs, openssl
pdcurses (3.3-1)
PDCurses
Required by: grass, msys-grass
proj (6.3.2-1)
The PROJ library and commands for coordinate system transformations.
Required by: qgis-common, gdal, spatialite, grass, liblwgeom, python3-pyproj, msys-grass, gdal111dll, liblas, qgis-ltr-common, gdal18dll
proj-datumgrid (1.8-1)
Assorted PROJ datum grid shift files
Required by: proj, liblas
proj-hpgn (1.0-1)
PROJ.4 HPGN (HARN) grid shift files
Required by: proj, liblas
pyopengl (3.0.1-1)
The Python OpenGL廬 Binding
Required by: msys-grass
pyqt5 (5.11.3-2)
Python bindings for Qt5.
Required by: qgis, qgis-ltr, python3-qscintilla
python (2.7.4-2)
Python meta package, includes core interpreter & runtime, help, tcl/tk & idle, tools and test suite
Required by: python-wx, pyopengl, python-win32
python-core (2.7.14-1)
Python core interpreter and runtime
Required by: python-numpy, python, python-pillow, python-help, python-tcltk, python-tools, python-olefile, python-test
python-help (2.7.14-1)
Python documentation in a Windows compiled help file
Required by: python
python-numpy (2.7-1.7.0-1)
NumPy is the fundamental package for array computing with Python.
Required by: msys-grass
python-olefile (0.44-1)
Python package to parse, read and write Microsoft OLE2 files (Structured Storage or Compound Document, Microsoft Office) - Improved version of the OleFileIO module from PIL, the Python Image Library.
Required by: python-pillow
python-pil (1.1.7-2)
Python Imaging Library (PIL; transitional for pillow)
Required by: msys-grass
python-pillow (5.3.0-1)
Python Imaging Library (Fork)
Required by: python-pil
python-tcltk (2.7.14-1)
Python Tkinter and IDLE
Required by: python
python-test (2.7.14-1)
Python self tests
Required by: python-testsuite
python-testsuite (2.7.14-1)
Python Lib/test: bsddb, ctypes, distutils, email, json, lib-tk, lib2to3, sqlite3, test, unittest (transitional package)
Required by: python
python-tools (2.7.14-1)
Python Tools
Required by: python
python-win32 (2.16-1)
Python for Windows extension
Required by: python-wx
python-wx (2.8.12.1-1)
wxPython - Python bindings for wxWidgets
Required by: msys-grass
python3-certifi (2019.11.28-1)
Python package for providing Mozilla's CA Bundle.
Required by: python3-requests
python3-chardet (3.0.4-2)
Universal encoding detector for Python 2 and 3
Required by: python3-requests
python3-core (3.7.0-4)
Python3 core interpreter and runtime
Required by: sip-qt5, qgis, qgis-ltr, pyqt5, python3-gdal, python3-qscintilla, python3-jinja2, python3-markupsafe, python3-pygments, python3-python-dateutil, python3-pytz, python3-future, python3-requests, python3-pyproj, python3-pyyaml, python3-plotly, python3-owslib, python3-httplib2, python3-nose2, python3-mock, python3-matplotlib, python3-wx, python3-numpy, python3-pillow, python3-pip, python3-ply, python3-pyopengl, python3-six, python3-pywin32, python3-psycopg2-binary, python3-idna, python3-chardet, python3-certifi, python3-urllib3, python3-retrying, python3-decorator, python3-nbformat, python3-coverage, python3-pbr, python3-cycler, python3-pyparsing, python3-kiwisolver, python3-ipython-genutils, python3-jsonschema, python3-jupyter-core, python3-traitlets, python3-setuptools
python3-coverage (4.5.1-1)
Code coverage measurement for Python
Required by: python3-nose2
python3-cycler (0.10.0-2)
Composable style cycles
Required by: python3-matplotlib
python3-decorator (4.4.1-1)
Decorators for Humans
Required by: python3-plotly, python3-traitlets
python3-future (0.16.0-2)
Clean single-source support for Python 3 and 2
Required by: qgis, qgis-ltr
python3-gdal (3.0.4-2)
The GDAL/OGR Python3 Bindings and Scripts
Required by: qgis, grass, qgis-ltr
python3-httplib2 (0.11.3-1)
A comprehensive HTTP client library.
Required by: qgis, qgis-ltr
python3-idna (2.8-1)
Internationalized Domain Names in Applications (IDNA)
Required by: python3-requests
python3-ipython-genutils (0.2.0-2)
Vestigial utilities from IPython
Required by: python3-nbformat, python3-traitlets
python3-jinja2 (2.11.1-1)
A small but fast and easy to use stand-alone template engine written in pure python.
Required by: qgis, qgis-ltr
python3-jsonschema (2.6.0-2)
An implementation of JSON Schema validation for Python
Required by: python3-nbformat
python3-jupyter-core (4.6.2-1)
Jupyter core package. A base package on which Jupyter projects rely.
Required by: python3-nbformat
python3-kiwisolver (1.1.0-1)
A fast implementation of the Cassowary constraint solver
Required by: python3-matplotlib
python3-markupsafe (1.1.1-1)
Safely add untrusted strings to HTML/XML markup.
Required by: qgis, qgis-ltr, python3-jinja2
python3-matplotlib (3.1.3-1)
Python plotting package
Required by: grass
python3-mock (2.0.0-2)
Rolling backport of unittest.mock for all Pythons
Required by: qgis, qgis-ltr
python3-nbformat (5.0.4-1)
The Jupyter Notebook format
Required by: python3-plotly
python3-nose2 (0.8.0-1)
nose2 is the next generation of nicer testing for Python
Required by: qgis, qgis-ltr
python3-numpy (1.18.3-1)
NumPy is the fundamental package for array computing with Python.
Required by: grass, python3-gdal, python3-matplotlib
python3-owslib (0.17.0-1)
OGC Web Service utility library
Required by: qgis, qgis-ltr
python3-pbr (4.3.0-1)
Python Build Reasonableness
Required by: python3-mock
python3-pillow (5.3.0-1)
Python Imaging Library (Fork)
Required by: grass
python3-pip (20.0.2-1)
The PyPA recommended tool for installing Python packages.
Required by: grass
python3-plotly (3.3.0-1)
Python plotting library for collaborative, interactive, publication-quality graphs.
Required by: qgis, qgis-ltr
python3-ply (3.11-2)
Python Lex & Yacc
Required by: grass
python3-psycopg2 (2.8.4-1)
psycopg2 - Python-PostgreSQL Database Adapter (transitional)
Required by: qgis, grass, qgis-ltr
python3-psycopg2-binary (2.8.4-1)
psycopg2 - Python-PostgreSQL Database Adapter
Required by: python3-psycopg2
python3-pygments (2.5.2-1)
Pygments is a syntax highlighting package written in Python.
Required by: qgis, qgis-ltr
python3-pyopengl (3.1.0-1)
Standard OpenGL bindings for Python
Required by: grass
python3-pyparsing (2.4.6-1)
Python parsing module
Required by: python3-matplotlib
python3-pyproj (2.5.0-1)
Python interface to PROJ (cartographic projections and coordinate transformations library)
Required by: qgis, qgis-ltr, python3-owslib
python3-python-dateutil (2.8.1-1)
Extensions to the standard Python datetime module
Required by: qgis, qgis-ltr, python3-owslib, python3-matplotlib
python3-pytz (2019.3-1)
World timezone definitions, modern and historical
Required by: qgis, qgis-ltr, python3-plotly, python3-owslib
python3-pywin32 (227-1)
Python for Window Extensions
Required by: grass, python3-jupyter-core
python3-pyyaml (5.3-1)
YAML parser and emitter for Python
Required by: qgis, qgis-ltr
python3-qscintilla (2.10.8-1)
Python3 bindings for Qt5 QScintilla
Required by: qgis, qgis-ltr
python3-requests (2.22.0-1)
Python HTTP for Humans.
Required by: qgis, qgis-ltr, python3-plotly, python3-owslib
python3-retrying (1.3.3-1)
Retrying
Required by: python3-plotly
python3-setuptools (45.2.0-1)
Easily download, build, install, upgrade, and uninstall Python packages
Required by: python3-kiwisolver
python3-six (1.14.0-1)
Python 2 and 3 compatibility utilities
Required by: grass, python3-python-dateutil, python3-plotly, python3-nose2, python3-mock, python3-wx, python3-retrying, python3-cycler, python3-traitlets
python3-traitlets (4.3.3-1)
Traitlets Python config system
Required by: python3-nbformat, python3-jupyter-core
python3-urllib3 (1.25.8-1)
HTTP library with thread-safe connection pooling, file post, and more.
Required by: python3-requests
python3-wx (4.0.7-1)
wxPython - Python3 bindings for wxWidgets
Required by: grass
qca-qt5-libs (2.1.3-1)
Qt5 Cryptographic Architecture runtime libraries
Required by: qgis-common, qgis-ltr-common
qgis (3.12.3-1)
QGIS Desktop
Required by: qgis-grass-plugin, qgis-grass-plugin7
qgis-ltr (3.10.6-1)
QGIS Desktop (long term release)
Required by: qgis-ltr-grass-plugin7
qgis-ltr-common (3.10.6-1)
QGIS (common; long term release)
Required by: qgis-ltr
qgis-ltr-grass-plugin-common (3.10.6-1)
GRASS plugin for QGIS (common; long term release)
Required by: qgis-ltr-grass-plugin7
qscintilla-qt5 (2.10.8-1)
Qt5 source code editing component.
Required by: qgis-common, python3-qscintilla, qgis-ltr-common
qt5-libs (5.11.2-2)
Qt5 runtime libraries
Required by: qgis-common, qwt-libs-qt5, qca-qt5-libs, qtkeychain-qt5-libs, qtwebkit-qt5-libs, qscintilla-qt5, icu-libs, pyqt5, qt5-qml, qt5-tools, qgis-ltr-common, qtwebengine-qt5-libs
qt5-qml (5.11.2-1)
Qt5 QML
Required by: qgis, qgis-ltr
qt5-tools (5.11.2-1)
Qt5 designer & linguist (Development)
Required by: qgis, qgis-ltr
qtkeychain-qt5-libs (0.9-1)
Platform-independent Qt API for storing passwords securely.
Required by: qgis-common, qgis-ltr-common
qtwebengine-qt5-libs (5.10.1-1)
WebEngine for Qt5
Required by: pyqt5
qtwebkit-qt5-libs (5.212-1)
WebKit for Qt5
Required by: qgis-common, pyqt5, qgis-ltr-common
qwt-libs-qt5 (6.1.3-5)
Qt5 widgets library for technical applications (runtime)
Required by: qgis-common, qgis-ltr-common
rbatch (149-4)
Windows batchfiles for use with R
Required by: grass
setup (1.0.7-16)
OSGeo4W Installer/Updater
Required by: shell
shell (1.0.2-4)
OSGeo4W Command Shell
Required by: gsl-libs, zlib, qwt-libs-qt5, iconv, qscintilla-qt5, expat, libxml2, openssl10, gpsbabel, python3-qscintilla, qt5-tools, libintl, tcltk, gdal111dll, liblas, avce00, pdcurses, fftw, libpng, cairo, setup, freetype-mingw, python-wx, pyopengl, libcairo, libjpeg, libgeotiff, gdal18dll, libjpeg12, python, python-win32
sip-qt5 (4.19.14-1)
Python3/C++ bindings generator (Development)
Required by: qgis-common, pyqt5, qgis-ltr-common
spatialite (4.3.0a-6)
The SpatiaLite library for adding spatial capabilities to SQLite3 DBMS.
Required by: qgis-common, gdal, gdal111dll, qgis-ltr-common
sqlite3 (3.29.0-1)
The SQLite3 library for accessing SQLite3 database files.
Required by: qt5-libs, gdal, spatialite, python3-core, gdal111dll, gdal18dll, python-core
szip (2.1.1-1)
SZIP compression library
Required by: hdf4, hdf5
tcltk (8.5.6-1)
Tcl/Tk
Required by: grass6
xerces-c (3.2.0-1)
The Xerces-C 3 library for parsing XML files (runtime)
Required by: gdal
xerces-c-vc9 (3.1.1-2)
The Xerces-C 3 VC9 library for parsing XML files
Required by: gdal111dll, gdal18dll
xz (5.2.3-1)
XZ-format compression library
Required by: gdal, libtiff
zlib (1.2.3-1)
The zlib compression and decompression library (runtime)
Required by: qgis-common, qt5-libs, grass, ogdi, openjpeg, libkml, gpsbabel, exiv2, msys-grass, libtiff, cairo, qgis-ltr-common
zstd (1.4.4-1)
Zstandard Long Range Match Finder (runtime)
Required by: gdal, grass, zstd-bin
zstd-bin (1.4.4-1)
Zstandard Long Range Match Finder (binary)
Required by: grass
10、一溜許可證頁面，需要點擊 同意，一路 NEXT。（圖就不都貼出來了）
11、這個頁面 是 安裝進度。（這個下載速度有點慢哦，建議 換下載站點或者起個大早。）
12、qgis安裝完畢。
13、通過osgeo4w軟件，除了安裝 qgis，還需要安裝以下依賴庫：
expat
fcgi
gdal
grass
gsl-devel
iconv
libspatialindex-devel
pyqt5
python3-devel
python3-qscintilla
python3-nose2
python3-future
python3-pyyaml
python3-mock
qca-qt5-devel
qca-qt5-libs
qscintilla-qt5
qt5-devel
qt5-libs-debug
qtwebkit-qt5-devel
qtwebkit-qt5-libs-debug
qwt-devel-qt5
sip-qt5
spatialite
qjson
注意點：
a、操作步驟與安裝 qgis 類似。
b、遵從“寧可多下，絕不少下”的原則。
c、僅下載Library的內容。
安裝cgywin
下載地址：
32位：http://cygwin.com/setup-x86.exe
64位：http://cygwin.com/setup-x86_64.exe
安裝步驟，可以參考：【Cygwin】解決Cygwin安裝時download mirror sites無效問題
cygwin主要是安裝”flex”和”bison”兩個工具。
安裝cmake
下載地址：https://cmake.org/files/v3.7/
各個平臺安裝都有，這裏選擇一個win-x86的。安裝步驟就不贅述了，標準的windows安裝包。
未完待續