Mixing
Why does my code only allow me to drag and drop the uppermost duplicate item in a listview box
I have some code (shown below) for a pc running c# within a Windows Forms Application using Microsoft Visual Studio.
I'm trying to implement user reordering of the text contents of a listview window using DragDrop and MouseDown instructions.
The problem I'm having is when I'm trying to re-order an item which has an exact duplicate (or duplicates) within the same listview window, whichever one I click to drag to move to a new position within the same list, the one that's moved is always the topmost one.
So, for instance, I could have one duplicate at the very bottom and one at the very top of the list and if I click and drag the bottom one and drop near the top, it's always the top duplicate that's moved rather than the one I actually dragged at the bottom. So the top one always seems to take priority.
private void Playlist_MouseDown(object sender, MouseEventArgs e)
{
int item_index_pickup = Playlist.IndexFromPoint(e.X, e.Y);
if (item_index_pickup >= 0 && item_index_pickup <
Playlist.Items.Count)
{
Playlist.DoDragDrop(Playlist.SelectedItem,
DragDropEffects.Move);
playlist_reorder = true;
}
}
private void Playlist_DragDrop(object sender, DragEventArgs e)
{
int item_index_drop = Playlist.IndexFromPoint(
Playlist.PointToClient(new Point(e.X, e.Y)));
Playlist.Items.Remove(Playlist.SelectedItem);
if (item_index_drop >= 0 && item_index_drop <
Playlist.Items.Count)
// Check whether item is inserted or added to end of list
{
Playlist.Items.Insert(item_index_drop,
e.Data.GetData(DataFormats.Text));
Playlist.ClearSelected();
}
else // Add item to the end of the list
{
string chosen_file = (string)e.Data.GetData
(DataFormats.StringFormat);
Playlist.Items.Add(chosen_file);
Playlist.ClearSelected();
}
}
Thanks for your insight and experience.
Martin
c# winforms listview
asked Nov 21 '18 at 2:09
MartinMartin
93
add a comment |
I have some code (shown below) for a pc running c# within a Windows Forms Application using Microsoft Visual Studio.
I'm trying to implement user reordering of the text contents of a listview window using DragDrop and MouseDown instructions.
The problem I'm having is when I'm trying to re-order an item which has an exact duplicate (or duplicates) within the same listview window, whichever one I click to drag to move to a new position within the same list, the one that's moved is always the topmost one.
So, for instance, I could have one duplicate at the very bottom and one at the very top of the list and if I click and drag the bottom one and drop near the top, it's always the top duplicate that's moved rather than the one I actually dragged at the bottom. So the top one always seems to take priority.
private void Playlist_MouseDown(object sender, MouseEventArgs e)
{
int item_index_pickup = Playlist.IndexFromPoint(e.X, e.Y);
if (item_index_pickup >= 0 && item_index_pickup <
Playlist.Items.Count)
{
Playlist.DoDragDrop(Playlist.SelectedItem,
DragDropEffects.Move);
playlist_reorder = true;
}
}
private void Playlist_DragDrop(object sender, DragEventArgs e)
{
int item_index_drop = Playlist.IndexFromPoint(
Playlist.PointToClient(new Point(e.X, e.Y)));
Playlist.Items.Remove(Playlist.SelectedItem);
if (item_index_drop >= 0 && item_index_drop <
Playlist.Items.Count)
// Check whether item is inserted or added to end of list
{
Playlist.Items.Insert(item_index_drop,
e.Data.GetData(DataFormats.Text));
Playlist.ClearSelected();
}
else // Add item to the end of the list
{
string chosen_file = (string)e.Data.GetData
(DataFormats.StringFormat);
Playlist.Items.Add(chosen_file);
Playlist.ClearSelected();
}
}
Thanks for your insight and experience.
Martin
c# winforms listview
asked Nov 21 '18 at 2:09
MartinMartin
93
It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37
add a comment |
I have some code (shown below) for a pc running c# within a Windows Forms Application using Microsoft Visual Studio.
I'm trying to implement user reordering of the text contents of a listview window using DragDrop and MouseDown instructions.
The problem I'm having is when I'm trying to re-order an item which has an exact duplicate (or duplicates) within the same listview window, whichever one I click to drag to move to a new position within the same list, the one that's moved is always the topmost one.
So, for instance, I could have one duplicate at the very bottom and one at the very top of the list and if I click and drag the bottom one and drop near the top, it's always the top duplicate that's moved rather than the one I actually dragged at the bottom. So the top one always seems to take priority.
private void Playlist_MouseDown(object sender, MouseEventArgs e)
{
int item_index_pickup = Playlist.IndexFromPoint(e.X, e.Y);
if (item_index_pickup >= 0 && item_index_pickup <
Playlist.Items.Count)
{
Playlist.DoDragDrop(Playlist.SelectedItem,
DragDropEffects.Move);
playlist_reorder = true;
}
}
private void Playlist_DragDrop(object sender, DragEventArgs e)
{
int item_index_drop = Playlist.IndexFromPoint(
Playlist.PointToClient(new Point(e.X, e.Y)));
Playlist.Items.Remove(Playlist.SelectedItem);
if (item_index_drop >= 0 && item_index_drop <
Playlist.Items.Count)
// Check whether item is inserted or added to end of list
{
Playlist.Items.Insert(item_index_drop,
e.Data.GetData(DataFormats.Text));
Playlist.ClearSelected();
}
else // Add item to the end of the list
{
string chosen_file = (string)e.Data.GetData
(DataFormats.StringFormat);
Playlist.Items.Add(chosen_file);
Playlist.ClearSelected();
}
}
Thanks for your insight and experience.
Martin
c# winforms listview
asked Nov 21 '18 at 2:09
MartinMartin
93
I have some code (shown below) for a pc running c# within a Windows Forms Application using Microsoft Visual Studio.
I'm trying to implement user reordering of the text contents of a listview window using DragDrop and MouseDown instructions.
The problem I'm having is when I'm trying to re-order an item which has an exact duplicate (or duplicates) within the same listview window, whichever one I click to drag to move to a new position within the same list, the one that's moved is always the topmost one.
So, for instance, I could have one duplicate at the very bottom and one at the very top of the list and if I click and drag the bottom one and drop near the top, it's always the top duplicate that's moved rather than the one I actually dragged at the bottom. So the top one always seems to take priority.
private void Playlist_MouseDown(object sender, MouseEventArgs e)
{
int item_index_pickup = Playlist.IndexFromPoint(e.X, e.Y);
if (item_index_pickup >= 0 && item_index_pickup <
Playlist.Items.Count)
{
Playlist.DoDragDrop(Playlist.SelectedItem,
DragDropEffects.Move);
playlist_reorder = true;
}
}
private void Playlist_DragDrop(object sender, DragEventArgs e)
{
int item_index_drop = Playlist.IndexFromPoint(
Playlist.PointToClient(new Point(e.X, e.Y)));
Playlist.Items.Remove(Playlist.SelectedItem);
if (item_index_drop >= 0 && item_index_drop <
Playlist.Items.Count)
// Check whether item is inserted or added to end of list
{
Playlist.Items.Insert(item_index_drop,
e.Data.GetData(DataFormats.Text));
Playlist.ClearSelected();
}
else // Add item to the end of the list
{
string chosen_file = (string)e.Data.GetData
(DataFormats.StringFormat);
Playlist.Items.Add(chosen_file);
Playlist.ClearSelected();
}
}
Thanks for your insight and experience.
Martin
c# winforms listview
c# winforms listview
asked Nov 21 '18 at 2:09
MartinMartin
93
asked Nov 21 '18 at 2:09
MartinMartin
93
edited Nov 22 '18 at 18:14
Martin
asked Nov 21 '18 at 2:09
MartinMartin
93
asked Nov 21 '18 at 2:09
MartinMartin
93
asked Nov 21 '18 at 2:09
MartinMartin
93
93
It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37
add a comment |
It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37
It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37
add a comment |
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It would be awesome if you could provide a Minimal, Complete, and Verifiable example
– JohnB
Nov 21 '18 at 2:11
Show us your code.
– TerribleDog
Nov 21 '18 at 2:12
This is much more broad than you think - Microsoft seems to have a ListView in every platform/technology they support. Since you didnt indicate the technology (tags), we cant help.
– None of the Above
Nov 21 '18 at 4:13
It is not obvious to me how you could tell that the right one got "moved", given that they are duplicates. The code does have a basic bug, it doesn't move the selected item, it copies it. If a real move is intended then you have to Remove/At() the selected item and re-insert it at the target index.
– Hans Passant
Nov 23 '18 at 9:41
The way I can tell which got moved when I reorder is that I’m never able to move the bottom most one of the two (or more) duplicate items upwards - so whichever of the duplicate items I drag upwards (which may be separated in the list), the uppermost of the duplicate items is always moved. The uppermost of the duplicates is moved around freely regardless of which one I try to drag around. There is a remove line in the code above: Playlist.Items.Remove(Playlist.SelectedItem);
– Martin
Nov 24 '18 at 18:37