当我使用 QGridLayout 显示我的小部件时，只显示了小部件，而没有显示透明的图像部分。现在我切换到使用 QGraphicsScene 和 QGraphicsView，现在我的图像在过去是透明的地方都有灰色背景。
void Piece::paintEvent(QPaintEvent *)
{
string image = ":/images/" + color + piece + ".png";
pixmap.load(image.c_str());
//pixmap.setMask(pixmap.createMaskFromColor(QColor(240, 240, 240)));
QPainter paint(this);
paint.drawPixmap(0, 0, pixmap);
}
这就是图像在我的小部件上的显示方式。当我使用代码时，
layout->addWidget(0,0,1,1);
背景是透明的。但是当我使用时，
scene->addWidget(piece);
小部件具有灰色背景。我怎样才能使它透明？如有必要，可以在这里找到完整的代码（可能没有必要）：https ://github.com/gsingh93/Chess
编辑：我根本无法解决这个问题......我尝试使用 setAutoFillBackground(false); 但这没有用。所以我最后的希望是将我的整个班级从 QWidget 转换为 QGrahhicsItem。那没有用，图像的背景仍然是灰色而不是透明。如果您无法弄清楚此代码有什么问题，有人可以发布或链接我到如何使用 QGraphicsScene 显示具有透明背景的图像的示例吗？这是原始代码，然后是QGraphicsItem代码，然后是我的main函数。
#include "headers/piece.h"
#include <QPainter>
#include <QMouseEvent>
#include <QBitmap>
#include <QCursor>
using namespace std;
Piece::Piece(string color, string piece, QWidget *parent) :
QWidget(parent)
{
this->piece = piece;
this->color = color;
this->setMaximumHeight(36);
this->setMaximumWidth(36);
x = 0;
y = 0;
setMouseTracking(false);
}
void Piece::paintEvent(QPaintEvent *)
{
string image = ":/images/" + color + piece + ".png";
pixmap.load(image.c_str());
//pixmap.setMask(pixmap.createMaskFromColor(QColor(240, 240, 240)));
QPainter paint(this);
paint.drawPixmap(0, 0, pixmap);
}
void Piece::setPosition(int file, int rank)
{
pixmap.load(":/images/whitepawn.png");
QImage image = pixmap.toImage();
x = (file-1)*50 + 18;// - image.width()/2;
y = (rank-1)*50 + 18;// - image.height()/2;
move(x, y);
}
void Piece::mouseMoveEvent(QMouseEvent *event)
{
if(event->buttons() == Qt::LeftButton)
{
x = event->globalX()-18;
y = event->globalY()-18;
move(x,y);
}
}
.
#include "piece2.h"
#include <QPainter>
#include <QMouseEvent>
#include <QBitmap>
#include <QCursor>
#include <QGraphicsSceneMouseEvent>
using namespace std;
Piece2::Piece2(string color, string piece, QObject *parent) :
QGraphicsItem()
{
this->piece = piece;
this->color = color;
//this->setMaximumHeight(36);
//this->setMaximumWidth(36);
x = 0;
y = 0;
//setMouseTracking(false);
}
void Piece2::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
string image = ":/images/" + color + piece + ".png";
pixmap.load(image.c_str());
//pixmap.setMask(pixmap.createMaskFromColor(QColor(240, 240, 240)));
//QPainter paint(this);
painter->drawPixmap(0, 0, pixmap);
}
void Piece2::setPosition(int file, int rank)
{
pixmap.load(":/images/whitepawn.png");
QImage image = pixmap.toImage();
x = (file-1)*50 + 18;// - image.width()/2;
y = (rank-1)*50 + 18;// - image.height()/2;
setPos(x, y);
}
void Piece2::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
if(event->buttons() == Qt::LeftButton)
{
// x = event->globalX()-18;
// y = event->globalY()-18;
setPos(x,y);
}
}
.
#include <QtGui>
#include <QGraphicsScene>
#include <QGraphicsView>
#include "headers/board.h"
#include "headers/pawn.h"
#include "headers/knight.h"
#include "headers/bishop.h"
#include "headers/rook.h"
#include "headers/king.h"
#include "headers/queen.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QGraphicsScene *scene = new QGraphicsScene();
QGraphicsView *view = new QGraphicsView();
Board board;
scene->addWidget(&board);
scene->addWidget(board.pawn2);
board.pawn2->setPosition(1,1);
//view->viewport()->setPalette(QColor(Qt::transparent));
//view->viewport()->setAutoFillBackground(false);
view->setScene(scene);
//view->setBackgroundRole(QPalette::NoRole);
view->show();
return app.exec();
}