Question

我正在尝试使用Qt中的QStandardItemModel制作模型。我是通过以下两种方式完成的。在第二种方法中，我只是扩展了循环，我得到redefinition of 'item'错误，而第一种方法工作正常。

方法1

QStandardItemModel * model = new QStandardItemModel( 3, 1 );
QStringList modelStepsTags = {"item-1","item-2","item-3"};
for( int r=0; r<3; r=r+1 )
{
    QStandardItem *item = new QStandardItem( modelStepsTags.at(r) );
    model->setItem(r, 0, item);
}

方法2

QStandardItemModel * model = new QStandardItemModel( 3, 1 );
QStringList modelStepsTags = {"item-1","item-2","item-3"};
QStandardItem *item = new QStandardItem( modelStepsTags.at(0) );
model->setItem(0, 0, item);
QStandardItem *item = new QStandardItem( modelStepsTags.at(1) );
model->setItem(1, 0, item);
QStandardItem *item = new QStandardItem( modelStepsTags.at(2) );
model->setItem(2, 0, item);

Answer 1

项目定义了三次。

QStandardItemModel * model = new QStandardItemModel( 3, 1 );
QStringList modelStepsTags = {"item-1","item-2","item-3"};
QStandardItem *item = new QStandardItem( modelStepsTags.at(0) ); // here
model->setItem(0, 0, item);
QStandardItem *item = new QStandardItem( modelStepsTags.at(1) ); // here
model->setItem(1, 0, item);
QStandardItem *item = new QStandardItem( modelStepsTags.at(2) ); // and here
model->setItem(2, 0, item);

您可以重复使用第一个定义

QStandardItemModel * model = new QStandardItemModel( 3, 1 );
QStringList modelStepsTags = {"item-1","item-2","item-3"};
QStandardItem *item = new QStandardItem( modelStepsTags.at(0) );
model->setItem(0, 0, item);
item = new QStandardItem( modelStepsTags.at(1) ); // reuse
model->setItem(1, 0, item);
item = new QStandardItem( modelStepsTags.at(2) ); // reuse
model->setItem(2, 0, item);

或完全丢弃变量，因为它是多余的

QStandardItemModel * model = new QStandardItemModel( 3, 1 );
QStringList modelStepsTags = {"item-1","item-2","item-3"};
model->setItem(0, 0, new QStandardItem( modelStepsTags.at(0) ));
model->setItem(1, 0, new QStandardItem( modelStepsTags.at(1) ));
model->setItem(2, 0, new QStandardItem( modelStepsTags.at(2) ));

QStandardItem重定义错误

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