Qt中QString的sprintf（）函数里参数类型是什么？？？
我想把QTableWidget里数据保存成.txt文本，但是我按下面这样写，虽然可以输出，但是文本有点乱，因为Smart_Table->item(i,0);里的内容长短不一，
所以我要用 str.sprintf("%s %-30s %-7s %-6s %-7s %-7s %-30s",
(Smart_Table->item(i,0)->text()),
(Smart_Table->item(i,1)->text()),
(Smart_Table->item(i,2)->text()),
(Smart_Table->item(i,3)->text()),
(Smart_Table->item(i,4)->text()),
(Smart_Table->item(i,5)->text()),
(Smart_Table->item(i,6)->text())
);
这种写法，可是这么写会报错，这是为什么？？？下面是我的代码，我想用屏蔽的那种写法。
谢谢！！！
for (int i = 1; i < 30; i++)
{
if (Smart_Table->item(i,0)->text()!= "")
{
QString str;
//str.sprintf("%s %-30s %-7s %-6s %-7s %-7s %-30s",
//(Smart_Table->item(i,0)->text()),
//(Smart_Table->item(i,1)->text()),
//(Smart_Table->item(i,2)->text()),
//(Smart_Table->item(i,3)->text()),
//(Smart_Table->item(i,4)->text()),
//(Smart_Table->item(i,5)->text()),
//(Smart_Table->item(i,6)->text())
//);
QTableWidgetItem *item00 = Smart_Table->item(i,0);
QTableWidgetItem *item01 = Smart_Table->item(i,1);
QTableWidgetItem *item02 = Smart_Table->item(i,2);
QTableWidgetItem *item03 = Smart_Table->item(i,3);
QTableWidgetItem *item04 = Smart_Table->item(i,4);
QTableWidgetItem *item05 = Smart_Table->item(i,5);
QTableWidgetItem *item06 = Smart_Table->item(i,6);
out<<item00->text()<< "\t"<<item01->text()<< "\t"
<<item02->text()<< "\t"<<item03->text()<< "\t"
<<item04->text()<< "\t"<<item05->text()<< "\t"
<<item06->text()<< "\t"<<endl;
// out<<str<<endl;
