QTreeWidget的列所需的最小宽度可以使用QFontMetrics类计算得到。具体步骤如下:
- 获取当前QTreeWidget使用的字体,例如:
QFont font = tree_widget.font();
- 使用获取到的字体创建一个QFontMetrics对象,例如:
QFontMetrics font_metrics(font);
- 遍历所有子项,对于每个子项调用text()函数获取其在指定列上显示的文本内容,并通过QFontMetrics对象计算出该文本所需的最小宽度。比如,对于第二列来说,可以这样计算:
int col = 1; // 第二列
int min_width = 0;
for (int i = 0; i < tree_widget.topLevelItemCount(); ++i) {
QTreeWidgetItem *item = tree_widget.topLevelItem(i);
QString text = item->text(col);
int width = font_metrics.horizontalAdvance(text);
if (width > min_width) {
min_width = width;
}
}
- 对于每一列都重复上述步骤,并将计算出来的最小宽度存储起来。
完整代码示例:
#include <QApplication>
#include <QTreeWidget>
#include <QFontMetrics>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QTreeWidget tree_widget;
tree_widget.setHeaderLabels(QStringList() << "Name" << "Value");
QTreeWidgetItem *root_item = new QTreeWidgetItem(&tree_widget);
root_item->setText(0, "Root");
for (int i = 0; i < 10; ++i) {
QTreeWidgetItem *child_item = new QTreeWidgetItem(root_item);
child_item->setText(0, QString("Child %1").arg(i+1));
child_item->setText(1, QString("%1").arg(i+1));
}
tree_widget.expandItem(root_item);
QFont font = tree_widget.font();
QFontMetrics font_metrics(font);
QVector<int> col_min_widths(tree_widget.columnCount(), 0);
for (int col = 0; col < tree_widget.columnCount(); ++col) {
int min_width = 0;
for (int i = 0; i < tree_widget.topLevelItemCount(); ++i) {
QTreeWidgetItem *item = tree_widget.topLevelItem(i);
QString text = item->text(col);
int width = font_metrics.horizontalAdvance(text);
if (width > min_width) {
min_width = width;
}
}
col_min_widths[col] = min_width + 20; // 加上一些额外宽度,防止内容过于拥挤
}
// 设置每列的最小宽度
for (int col = 0; col < tree_widget.columnCount(); ++col) {
tree_widget.header()->resizeSection(col, col_min_widths[col]);
}
tree_widget.show();
return a.exec();
}