① 为什么使用gcc hello.c -fpie -pie -shared -o hello 编译出来
pie 选项用于编译可执行程序，而非lib
② 关于JFreeChart的几点问题
1.jfreechart-1.0.11-demo.jar只是实例，里面都是class文件，我当初是全部反编译之后再看这些例子的，例子很多；
2.真正需要添加的jar包是jfreechart-1.0.10.jar和jcommon-1.0.13.jar,抱歉我用的是10的,所以名称与你的11不一样
3.饼图例子
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartFrame;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PiePlot3D;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.ui.RectangleInsets;
public class FirstTest{
public static void main(String[] args){
// 第一步创建数据集
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("类别1", 125.3);
dataset.setValue("类别2", 52.7);
dataset.setValue("类别3", 10.6);
dataset.setValue("类别4", 85.96);
dataset.setValue("类别5", 43.2);
// 第二步创建一个JFreeChart对象
JFreeChart chart1 = ChartFactory.createPieChart(
"第一个饼图",
dataset, true, // 是否有图注
true, // 是否有提示
false // 是否有URLS
);
// 第三步让它显示
ChartFrame frame = new ChartFrame("test", chart1);
frame.setBounds(500, 200, 200, 200);
frame.pack();
frame.setVisible(true);
PiePlot3D plot =new PiePlot3D(dataset);
plot.setDepthFactor(0.10);
plot.setShadowPaint(null);
plot.setInsets(new RectangleInsets(100, 150, 100, 150));
// 设置饼图的起始角度
plot.setStartAngle(45);
plot.setForegroundAlpha(0.8f);
plot.setBackgroundAlpha(0.9f);
JFreeChart chart = new JFreeChart("hffirst", JFreeChart.DEFAULT_TITLE_FONT, plot, true);
chart.setBackgroundPaint(java.awt.Color.white);
ChartFrame frame1 = new ChartFrame("test1", chart);
frame1.setBounds(0, 0, 300, 300);
frame1.pack();
frame1.setVisible(true);
}
}
这个实际上会生成两个饼图，一个是二维的，一个三维的，有注释，可以参考
再说一下，demo包里面的东西真的很多，你可以反编译看源代码
③ 华为p30pro是安卓系统吗
华为P30手机采用EMUI 9.1.0（基于Android 9）操作系统，搭载麒麟980+8核处理器，多应用同时运行无压力，游戏运行更流畅。
④ 如何查看Apache的configure编译参数
`configure’ configures this package to adapt to many kinds of systems.
`configure’ 配置这个包来适合多数系统.
Usage: ./configure [OPTION]… [VAR=VALUE]…
语法: ./configure [选项]… [变量=值]…
To assign environment variables (e.g., CC, CFLAGS…), specify them as VAR=VALUE. See below for descriptions of some of the useful variables.
配置环境变量(例如,CC,CFLAGS),格式为VAR=VALUE. 看下面对这些可用变量的说明.
Defaults for the options are specified in brackets.
选项的默认值括在方括号之中.
Configuration:
配置:
-h, –help display this help and exit 显示这个帮助并退出
–help=short display options specific to this package 显示这个包的详细选项
–help=recursive display the short help of all the included packages 显示所有包括的包的帮助信息
-V, –version display version information and exit 显示版本信息并退出
-q, –quiet, –silent do not print `checking…’ messages 不打印’检查’信息
–cache-file=FILE cache test results in FILE [disabled] 存储测试信息到文件中 [disabled]
-C, –config-cache alias for `–cache-file=config.cache’ `–cache-file=config.cache’的别名
-n, –no-create do not create output files 不生成输出文件
–srcdir=DIR find the sources in DIR [configure dir or `..'] 在DIR查找代码
Installation directories:
安装目录:
–prefix=PREFIX install architecture-independent files in PREFIX 安装路径
[/usr/local/apache2]
–exec-prefix=EPREFIX install architecture-dependent files in EPREFIX 执行文件安装路径
[PREFIX]
By default, `make install’ will install all the files in `/usr/local/apache2/bin’, `/usr/local/apache2/lib’ etc. You can specify an installation prefix other than `/usr/local/apache2′ using `–prefix’,for instance `–prefix=$HOME’.
默认情况下,’make install’安装所有的文件在 `/usr/local/apache2/bin’, `/usr/local/apache2/lib’ 等等.你可以指定一个安装前缀 ‘–prefix’选项来改变安装位置，例如 `–prefix=$HOME’.
For better control, use the options below.
更详细的配置,使用下面的选项.
Fine tuning of the installation directories:
调整安装目录的选项:
–bindir=DIR user executables [EPREFIX/bin]
–sbindir=DIR system admin executables [EPREFIX/sbin]
–libexecdir=DIR program executables [EPREFIX/libexec]
–sysconfdir=DIR read-only single-machine data [PREFIX/etc]
–sharedstatedir=DIR modifiable architecture-independent data [PREFIX/com]
–localstatedir=DIR modifiable single-machine data [PREFIX/var]
–libdir=DIR object code libraries [EPREFIX/lib]
–includedir=DIR C header files [PREFIX/include]
–oldincludedir=DIR C header files for non-gcc [/usr/include]
–datarootdir=DIR read-only arch.-independent data root [PREFIX/share]
–datadir=DIR read-only architecture-independent data [DATAROOTDIR]
–infodir=DIR info documentation [DATAROOTDIR/info]
–localedir=DIR locale-dependent data [DATAROOTDIR/locale]
–mandir=DIR man documentation [DATAROOTDIR/man]
–docdir=DIR documentation root [DATAROOTDIR/doc/PACKAGE]
–htmldir=DIR html documentation [DOCDIR]
–dvidir=DIR dvi documentation [DOCDIR]
–pdfdir=DIR pdf documentation [DOCDIR]
–psdir=DIR ps documentation [DOCDIR]
System types:
系统类型:
–build=BUILD configure for building on BUILD [guessed]
–host=HOST cross-compile to build programs to run on HOST [BUILD]
–target=TARGET configure for building compilers for TARGET [HOST]
Optional Features:
可选的功能:
–disable-FEATURE do not include FEATURE (same as –enable-FEATURE=no)
–enable-FEATURE[=ARG] include FEATURE [ARG=yes]
–enable-layout=LAYOUT
–enable-v4-mapped Allow IPv6 sockets to handle IPv4 connections
–enable-exception-hook Enable fatal exception hook
–enable-maintainer-mode
Turn on debugging and compile time warnings
–enable-pie Build httpd as a Position Independent Executable
–enable-moles=MODULE-LIST
Space-separated list of moles to enable | “all” |
“most”
–enable-mods-shared=MODULE-LIST
Space-separated list of shared moles to enable |
“all” | “most”
–disable-authn-file file-based authentication control
–enable-authn-dbm DBM-based authentication control
–enable-authn-anon anonymous user authentication control
–enable-authn-dbd SQL-based authentication control
–disable-authn-default authentication backstopper
–enable-authn-alias auth provider alias
–disable-authz-host host-based authorization control
–disable-authz-groupfile
‘require group’ authorization control
–disable-authz-user ‘require user’ authorization control
–enable-authz-dbm DBM-based authorization control
–enable-authz-owner ‘require file-owner’ authorization control
–enable-authnz-ldap LDAP based authentication
–disable-authz-default authorization control backstopper
–disable-auth-basic basic authentication
–enable-auth-digest RFC2617 Digest authentication
–enable-isapi isapi extension support
–enable-file-cache File cache
–enable-cache dynamic file caching
–enable-disk-cache disk caching mole
–enable-mem-cache memory caching mole
–enable-dbd Apache DBD Framework
–enable-bucketeer buckets manipulation filter
–enable-mpio I/O mp filter
–enable-echo ECHO server
–enable-example example and demo mole
–enable-case-filter example uppercase conversion filter
–enable-case-filter-in example uppercase conversion input filter
–enable-ext-filter external filter mole
–disable-include Server Side Includes
–disable-filter Smart Filtering
–disable-charset-lite character set translation
–enable-charset-lite character set translation
–enable-deflate Deflate transfer encoding support
–enable-ldap LDAP caching and connection pooling services
–disable-log-config logging configuration
–enable-log-forensic forensic logging
–enable-logio input and output logging
–disable-env clearing/setting of ENV vars
–enable-mime-magic automagically determining MIME type
–enable-cern-meta CERN-type meta files
–enable-expires Expires header control
–enable-headers HTTP header control
–enable-ident RFC 1413 identity check
–enable-usertrack user-session tracking
–enable-unique-id per-request unique ids
–disable-setenvif basing ENV vars on headers
–enable-version determining httpd version in config files
–enable-proxy Apache proxy mole
–enable-proxy-connect Apache proxy CONNECT mole
–enable-proxy-ftp Apache proxy FTP mole
–enable-proxy-http Apache proxy HTTP mole
–enable-proxy-ajp Apache proxy AJP mole
–enable-proxy-balancer Apache proxy BALANCER mole
–enable-ssl SSL/TLS support (mod_ssl)
–enable-distcache Select distcache support in mod_ssl
–enable-optional-hook-export
example optional hook exporter
–enable-optional-hook-import
example optional hook importer
–enable-optional-fn-import
example optional function importer
–enable-optional-fn-export
example optional function exporter
–enable-static-support Build a statically linked version of the support
binaries
–enable-static-htpasswd
Build a statically linked version of htpasswd
–enable-static-htdigest
Build a statically linked version of htdigest
–enable-static-rotatelogs
Build a statically linked version of rotatelogs
–enable-static-logresolve
Build a statically linked version of logresolve
–enable-static-htdbm Build a statically linked version of htdbm
–enable-static-ab Build a statically linked version of ab
–enable-static-checkgid
Build a statically linked version of checkgid
–enable-static-htcacheclean
Build a statically linked version of htcacheclean
–enable-static-httxt2dbm
Build a statically linked version of httxt2dbm
–enable-http HTTP protocol handling
–disable-mime mapping of file-extension to MIME
–enable-dav WebDAV protocol handling
–disable-status process/thread monitoring
–disable-autoindex directory listing
–disable-asis as-is filetypes
–enable-info server information
–enable-suexec set uid and gid for spawned processes
–disable-cgid CGI scripts
–enable-cgi CGI scripts
–disable-cgi CGI scripts
–enable-cgid CGI scripts
–enable-dav-fs DAV provider for the filesystem
–enable-dav-lock DAV provider for generic locking
–enable-vhost-alias mass virtual hosting mole
–disable-negotiation content negotiation
–disable-dir directory request handling
–enable-imagemap server-side imagemaps
–disable-actions Action triggering on requests
–enable-speling correct common URL misspellings
–disable-userdir mapping of requests to user-specific directories
–disable-alias mapping of requests to different filesystem parts
–enable-rewrite rule based URL manipulation
–enable-so DSO capability
Some influential environment variables:
一些有影响的环境变量:
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a
nonstandard directory <lib dir>
CPPFLAGS C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CPP C preprocessor
⑤ 这个C语言的图形程序为什么编译时会提示所调用的函数没有定义呢
是在链接的时候提示的错误吧？
解决方法看这里：http://tieba..com/p/910010397
2楼就是你需要做的设置。
主要就是因为你没有链接图形库。
⑥ 怎么样在udk下面编写应用程序，包括编译
你写的脚本UC文件要明确保存在development/src/...文件下，然后要建一个文件夹，打个比方，文件夹命名为UDNGame.然后再这个文件夹里边再建一个文件夹，必须命名为classes，然后再classes文件夹里边，放入你写入的uc脚本文件。一定记住，要有一个GameInfo类型的文件，主要是说明这个包里所用的脚本包含哪些。
然后进入UDK 在菜单栏里边找View -- World Properties -- Game Type -- Game Type for PIE 把游戏类型改成你的UDNGame就可以了
⑦ 在Linux下进行mpi程序的编译时，出现错误提示关于链接的
缺少了库文件。
在链接选项中增加mpi相对应的库文件，或者在代码中增加
#pragma comment (lib, "yourmpi.lib")
就可以了。
⑧ 荣耀V20与荣耀20有什么区别
两款手机对比参数如下：
1.屏幕：荣耀20屏幕尺寸6.26英寸，分辨率：FHD+ 2340×1080像素。前置镜头潜隐于屏幕下方，每次点亮屏幕，带来满屏视野，沉浸全视界。荣耀 V20屏幕尺寸6.4英寸，分辨率：FHD+ 2310×1080像素，屏占比为91.82%，高清大屏，魅眼全视屏，沉浸全视界，令你沉浸于精彩纷呈的显示画面中。屏幕色彩同为1670万色。
2.拍照：荣耀20后置摄像头：4800万像素（f/1.8光圈 AF）+1600万像素（f/2.2光圈 FF）+200万像素（f/2.4光圈 FF）+200万像素（f/2.4光圈 FF），支持自动对焦（相位对焦/反差对焦）。日夜拍都清晰，时刻精彩。前置单摄：3200万像素，f/2.0光圈，支持固定焦距。荣耀 V20后置摄像头：4800万像素（f/1.8光圈）+TOF立体深感镜头，支持自动对焦，前置摄像头：2500万像素，f/2.0光圈，支持固定焦距，4800万像素摄像头搭配AI超清算法，照片细节放大后依然清晰。
3.性能：二者都采用HUAWEI Kirin 980 (麒麟980)八核处理器，可以轻松驾驭重载大型游戏，带来满帧畅爽的卓越游戏体验和续航体验。
4.电池：荣耀20电池容量：3750mAh（典型值），标配充电器支持 5V/4.5A或5V/2A输出，支持5V/4.5A超级快充，兼容10V/2A快充，高密度大电池，强劲续航。荣耀 V20电池容量：4000mAh（典型值），标配充电器支持4.5V/5A或5V/4.5A或5V/2A输出，充电时间快，续航时间长。两款手机理论充电时间约1.5小时。
您可以登录华为商城官网了解更多参数，进行选择。