正确复制QTableView中的选择（模型索引问题） [英] Copying a selection in a QTableView properly (model index issues)
问题描述
我有一个 QTableView 显示从文件解析的数据。我打开文件，根据文件中每行的分隔符将其解析为不同的列，然后将其输出到视图。我使用了 QStandardItemModel 。
I have a QTableView that displays parsed data from a file. I open the file, parse it into different columns based on its delimiter for each line in the file, and then output it to the view. I am using a QStandardItemModel for this.
设置模型的相关代码：
QStandardItemModel* model = new QStandardItemModel(this);
int lineIndex = 0;
QStringList headers;
headers << "Col1" << "Col2";
model->setHorizontalHeaderLabels(headers);
file.seek(0);
QTextStream inData(&file);
while (!inData.atEnd()){
QString line = inData.readLine();
QStringList lineToken = line.split(":"/*, QString::SkipEmptyParts*/);
for (int j = 0; j < lineToken.size(); j++) {
QString value = lineToken.at(j);
QStandardItem* item = new QStandardItem(value);
model->setItem(lineIndex, j, item);
}
lineIndex++;
}
ui->tableView->setModel(model);
ui->tableView->horizontalHeader()->setSectionsMovable(true);
注意，我有它，所以我可以拖动列标题来重新排序表中的列。
Note that I have it so that I can drag the column headers around to reorder the columns in the table. This will be important later.
我也设置了视图，以便我可以选择整行（或单个单元格），按Ctrl + C，选择内容复制到剪贴板。我为选定的项/行制作了一个单独的模型：
I also have the view set up so that I can select an entire row (or individual cells), hit Ctrl+C, and have the contents of the selection copy to the clipboard. I made a separate model for the selected items/rows:
QApplication::clipboard()->clear();
QItemSelectionModel* selection = ui->tableView->selectionModel();
QModelIndexList indexes = selection->selectedIndexes();
QString clipboardString;
QModelIndexList selectedIndexes = ui->tableView->selectionModel()->selectedIndexes();
然后我有一些代码来处理如果选择跨越多行会发生什么。我为此设置了 QModelIndex 。实现这一点很简单。我使用for循环遍历所选单元格的索引。如果下一个索引（列）与当前的索引在同一行，我将该数据添加到变量，我将最终写入剪贴板并附加一个选项卡（ \t ）（因为我想要复制的单元格由选项卡分隔，所以我可以轻松地复制到剪贴板并粘贴到Excel如果我想要的）。如果下一个索引（列）在一个DIFFERENT行，那么我附加一个换行符（ \\\）。这里是代码：
I then have some code to handle what happens if the selection spans multiple rows. I set up a QModelIndex for this. The implementation for this is simple. I use a for loop to iterate through the indices of the selected cells. If the next index (column) is on the same row as the current one, I add that data to the variable I will eventually write to the clipboard and append a tab (\t) to it (since I want the copied cells to be delimited by tabs so I can easily copy to the clipboard and paste into Excel if I want). If the next index (column) is on a DIFFERENT row, then I append a line break (\n). Here is the code:
for (int i = 0; i < selectedIndexes.count(); ++i)
{
QModelIndex current = selectedIndexes[i];
QString displayText = current.data(Qt::DisplayRole).toString();
// If there exists another column beyond this one.
if (i + 1 < selectedIndexes.count()) {
QModelIndex next = selectedIndexes[i+1];
// If the column is on different row, the clipboard should take note.
qDebug() << "next.row()" << next.row();
qDebug() << "current.row()" << current.row();
if (next.row() != current.row()){
displayText.append("\n");
} else {
// Otherwise append a column separator.
displayText.append("\t");
}
}
clipboardString.append(displayText);
}
QApplication::clipboard()->setText(clipboardString);
这里是我遇到的问题。如果我重新排列我的视图中的列，索引检查断开。我的未经修改的视图如下所示：
Here's where I have a problem. If I rearrange the columns in my view, the index check breaks. My untouched view looks like this:
+------+------+
| Col1 | Col2 |
+------+------+
| A | B |
| W | X |
+------+------+
选择表中的任意值，我可以按Ctrl + C并按预期粘贴。没问题。在选择整个表格后进行复制和粘贴将产生以下输出：
If I select any of the values in the table, I can Ctrl+C and paste as expected. No problem. A copy and paste after selecting this entire table would result in this output:
A B
W X
但是，如果我将 Col1 拖到 Col2 是有效地将它们切换为如下所示：
However, if I drag Col1 over to where Col2 is, effectively switching them to look like this:
+------+------+
| Col2 | Col1 |
+------+------+
| B | A |
| X | W |
+------+------+
。然后选择整个东西并粘贴它，我得到这个输出：
...and select the entire thing and paste it, I get this output:
B
X
A
W
这显然不是我想要的， （ \\\）。
This is obviously not what I want and it seems to be adding a line break (\n) after every selected cell.
我的 qDebug（）第一个未修改表格的输出是：
My qDebug() outputs for the first, unmodified table are:
next.row() 0
current.row() 0
next.row() 1
current.row() 0
next.row() 1
current.row() 1
对于第二个重新排列的表，我的 qDebug（）输出是：
My qDebug() outputs for the second, rearranged table are:
next.row() 1
current.row() 0
next.row() 0
current.row() 1
next.row() 1
current.row() 0
我在这里做什么？为什么重要的是视图中的列重新排列？
What am I doing wrong here? Why would it matter that the columns in the view are rearranged?
推荐答案
以下似乎有效...
std::map<int/* row */, std::map<int/* col */, QString> > stuff;
int minCol = std::numeric_limits<int>::max();
int maxCol = std::numeric_limits<int>::min();
for (int i = 0; i < selectedIndexes.count(); ++i) {
QModelIndex current = selectedIndexes[i];
int col = horizontalHeader()->visualIndex(current.column());
stuff[current.row()][col] = current.data(Qt::DisplayRole).toString();
minCol = std::min(minCol, current.column());
maxCol = std::max(maxCol, current.column());
}
QString displayText;
for (const auto &byRow: stuff) {
for (int col = minCol; col <= maxCol; ++col) {
auto i = byRow.second.find(col);
if (i != byRow.second.end())
displayText += i->second;
displayText += col == maxCol ? "\n" : "\t";
}
}
请注意如何使用...映射索引列
Note how the index columns are mapped using...
int col = horizontalHeader()->visualIndex(current.column());
无论如何，看看这是否更接近你需要的东西。
Anyway, see if that's any closer to what you need.
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