| ceiwei |
2017-02-06 14:16 |
以下Qt程序显示出来的结果为何坐标是负值？
[attachment=16404]
关键代码是：
painter.drawText(20,1*50,tr("%1").arg((1*50)));
painter.drawText(20,2*50,tr("%1").arg((2*50)))
按道理i增加了，应该是在更高的位置显示出来，而这里的位置更低;所有代码是：
#include "pieview.h"
#include <QPainter>
PieView::PieView(QWidget *parent) :
QAbstractItemView(parent)
{
}
void PieView::paintEvent(QPaintEvent *)
{
QPainter painter(viewport());
painter.setPen(Qt::black);
int x0=40;
int y0=250;
//y坐标轴
painter.drawLine(x0,y0,40,30);
painter.drawLine(38,32,40,30);
painter.drawLine(40,30,42,32);
painter.drawText(20,30,tr("销售数量"));
painter.drawText(20,1*50,tr("%1").arg((1*50)));
painter.drawText(20,2*50,tr("%1").arg((2*50)));
//x 坐标轴
painter.drawLine(x0,y0,540,250);
painter.drawLine(538,248,540,250);
painter.drawLine(540,250,538,252);
painter.drawText(545,250,tr("品牌"));
int pos=x0+20;
int row;
for(row=0;row<model()->rowCount(rootIndex());row++)
{
QModelIndex index=model()->index(row,0,rootIndex());
QString dep=model()->data(index).toString();
painter.drawText(pos,y0+20,dep);
pos+=50;
}
int posN=x0+20;
for(row=0;row<model()->rowCount(rootIndex());row++)
{
QModelIndex index=model()->index(row,1,rootIndex());
int sell=model()->data(index).toDouble();
int width=10;
QModelIndex colorIndex = model()->index(row,0,rootIndex());
QColor color = QColor(model()->data(colorIndex,Qt::DecorationRole).toString());
if(selections->isSelected(index))
painter.setBrush(QBrush(color,Qt::Dense3Pattern));
else
painter.setBrush(QBrush(color));
painter.drawRect(QRect(posN,y0-sell*10,width,sell*10));
QRegion regionM(posN,y0-sell*10,width,sell*10);
RegionList<<regionM;
posN+=50;
}
}
void PieView::setSelectionModel(QItemSelectionModel *selectionModel)
{
selections = selectionModel;
}
QRegion PieView::itemRegion(QModelIndex index)
{
QRegion region;
if (index.column() == 1) // 销售数量
region = RegionList[index.row()];
return region;
}
QModelIndex PieView::indexAt(const QPoint &point) const
{
QPoint newPoint(point.x(),point.y());
QRegion region;
foreach(region,RegionList) // 销售数量 列
{
if (region.contains(newPoint))
{
int row = RegionList.indexOf(region);
QModelIndex index = model()->index(row,1,rootIndex());
return index;
}
}
return QModelIndex();
}
QRect PieView::visualRect(const QModelIndex &index) const{}
void PieView::scrollTo(const QModelIndex &index, ScrollHint hint){}
QModelIndex PieView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifiers modifiers){}
int PieView::horizontalOffset()const{}
int PieView::verticalOffset()const{}
bool PieView::isIndexHidden(const QModelIndex &index) const{}
void PieView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command){}
QRegion PieView::visualRegionForSelection(const QItemSelection &selection) const{}
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