在Qt

Question

我正在尝试使用Qt绘制一个基本方块，我的问题是颜色与我预期的不同。我想在红色边框的贪婪背景上的蓝色方块。相反，我得到了你在图片上看到的东西。应该怎么做？

#include <QPixmap>
#include <QPainter>
#include <QRect>
#include <QLabel>

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QPixmap pix(200,100);
    QPainter painter(&pix);

    painter.setBackground(QBrush("#1ac500")); //green
    painter.setPen(QColor("#bd3758")); //red
    painter.setBrush(QBrush("#377dbd"));//blue
    QRect rect(10,10,50,50);

    painter.drawRect(rect);
    painter.end();
    ui->label->setPixmap(pix);
}

我也试过了，但效果相同

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPixmap pix(200,100);
QPainter painter(&pix);
painter.setBackground(QBrush("#1ac500")); //green
painter.setPen(Qt::red); //red
QRect rect(10,10,50,50);
painter.fillRect(rect,Qt::red);

painter.drawRect(rect);
painter.end();
ui->label->setPixmap(pix);
}

我的.ui文件

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="windowModality">
   <enum>Qt::NonModal</enum>
  </property>
  <property name="enabled">
   <bool>false</bool>
  </property>
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>1920</width>
    <height>1080</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>50</y>
      <width>1820</width>
      <height>980</height>
     </rect>
    </property>
    <property name="text">
     <string>TextLabel</string>
    </property>
    <property name="alignment">
     <set>Qt::AlignLeading|Qt::AlignLeft|Qt::AlignTop</set>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>1920</width>
     <height>25</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="actionGenerate_Map"/>
    <addaction name="actionLoad_Map"/>
   </widget>
   <widget class="QMenu" name="menuEdit">
    <property name="title">
     <string>Edit</string>
    </property>
    <addaction name="actionPreferences"/>
   </widget>
   <widget class="QMenu" name="menuHelp">
    <property name="title">
     <string>Help</string>
    </property>
    <addaction name="actionAbout"/>
    <addaction name="actionAuthor"/>
   </widget>
   <addaction name="menuFile"/>
   <addaction name="menuEdit"/>
   <addaction name="menuHelp"/>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
  <action name="actionGenerate_Map">
   <property name="text">
    <string>Generate Map</string>
   </property>
  </action>
  <action name="actionPreferences">
   <property name="text">
    <string>Preferences</string>
   </property>
  </action>
  <action name="actionAbout">
   <property name="text">
    <string>About</string>
   </property>
  </action>
  <action name="actionAuthor">
   <property name="text">
    <string>Author</string>
   </property>
  </action>
  <action name="actionLoad_Map">
   <property name="text">
    <string>Load Map</string>
   </property>
  </action>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>