UI Layout broken in later previews.

[CodedBeard]

• .NET Core Version: 3.0 preview 9
• Have you experienced this same bug with .NET Framework?: No

Problem description:
We are porting a .Net framework winforms app to core. Up until preview 6, all of the ui was working exactly the same to .net framework, but since preview 6 we've started encountering various things that no longer behave as before. The first example is on the start form for the application, where the menu panel is no longer centered correctly.

Expected behavior: .NET Framework and Core 3.0 previews 1-5 look like this

Actual behavior: Preview 6-9 do this

Minimal repro:
uibug.zip

[kirsan31]

We have 2 problems here.

1. Centering issue. Appear only if WindowState = System.Windows.Forms.FormWindowState.Maximized;
2. Controls size issue. All controls is bigger on core. For example, main form grow from 864x740 to 1101х958.
   

Upd.

The problem in this line of code in Form1.Designer.cs (using depreciated AutoScaleBaseSize):
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
And different DPI policies between .net and core.

But I think we still need an answer is this expected behavior or not.

[RussKie]

2. Controls size issue. All controls is bigger on core. For example, main form grow from 864x740 to 1101х958.

This is by design due to the change of the DefaultFont (#656).
More information is here dotnet/docs#14143

[RussKie]

As pointed the issue disappears if this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); line is commented out in the form's designer.

@dreddy-work any thoughts?

[RussKie]

If you look at the code there are few things to note:

https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/Form.cs#L521-L547

1. we strongly recommend to upgrade to AutoScaleDimensions property
2. if AutoScaleBaseSize isn't explicitly set, it gets calculated based on the form's font: https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/Form.cs#L543
3. GetAutoScaleSize is marked as obsolete and instead recommends AutoScaleDimensions instead: https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/Form.cs#L3879-L3881

So it looks like a designer issue that can be resolved by removing the offending line. I'm not quite sure what other fix we can offer.
@dotnet/dotnet-winforms any thoughts?

@DustinCampbell how does the new designer handle this property?

@OliaG this is something you may wish to document as well.

[DustinCampbell]

The new designer would do the same thing, though it could be changed to something else if there's a need.

[RussKie]

Given that the codepath appears to be using obsolete API, should the new designer remove AutoScaleBaseSize property and replace it with AutoScaleDimensions?
Users will still need to remove AutoScaleBaseSize but at least if they opened a form in the designer and then save it, the designer would fix it for them.

[CodedBeard]

Thanks for pointing out where this issue was occurring, I spent many hours trying to figure out which bit was causing it before logging this. Replacing all the calls with AutoScaleDimensions does seem to have resolved most of the UI issues. You mention these API's are obsolete, however that doesn't appear to be surfaced in the VS warnings list like i would have expected. Should it be?

There is one other major UI issue we have noticed since going past preview 5. We have a DataGrid that applies a table style which resizes the columns based on the content. Once going past preview 5, any forms with this DataGridTableStyle hang upon first load and cause the form to flicker, however if you then close the form and reopen it again the form loads and works correctly.

This is the code for the DataGridTableStyle:

public DataGridTableStyle DataGridApplyAutomaticWidths(DataGrid DataGrid, int NumberOfRowsToScan, int MaxPixelWidth)
        {
            // Create graphics object for measuring widths.
            var Graphics = DataGrid.CreateGraphics();
            // Define new table style.
            var TableStyle = new DataGridTableStyle();
            try
            {
                DataTable DataTable;
                DataTable = ((DataTable)DataGrid.DataSource).DataSet.Tables[0];
                // Can only scan rows if they exist.
                NumberOfRowsToScan = Math.Min(NumberOfRowsToScan, DataTable.Rows.Count);
                // Clear any existing table styles.
                DataGrid.TableStyles.Clear();
                // Use mapping name that is defined in the data source.
                TableStyle.MappingName = DataTable.TableName;
                // Now create the column styles within the table style.

                // Dim ColumnStyle As DataGridTextBoxColumn
                MultiLineColumn ColumnStyle;
                int Width;
                foreach (DataColumn Column in DataTable.Columns)
                {
                    // ColumnStyle = New DataGridTextBoxColumn
                    ColumnStyle = new MultiLineColumn();
                    {
                        var withBlock = ColumnStyle;
                        withBlock.TextBox.Enabled = true;
                        withBlock.HeaderText = Column.ColumnName;

                        // Column Name Conversion
                        switch (Column.ColumnName)
                        {
                            case "CallDate":
                                {
                                    withBlock.HeaderText = "Call Date";
                                    break;
                                }

                            case "CallTime":
                                {
                                    withBlock.HeaderText = "Call Time";
                                    break;
                                }

                            case "BiffpackPerson":
                                {
                                    withBlock.HeaderText = "Biffpack User";
                                    break;
                                }

                            case "CustomerName":
                                {
                                    withBlock.HeaderText = "Customer Name";
                                    break;
                                }

                            case "CallLogCategory":
                                {
                                    withBlock.HeaderText = "Category";
                                    break;
                                }
                        }

                        withBlock.MappingName = Column.ColumnName;
                        // Set width to header text width.
                        Width = (int)Graphics.MeasureString(withBlock.HeaderText, DataGrid.Font, MaxPixelWidth).Width;
                    }
                    // Change width, if data width is wider than header text width.
                    // Check the width of the data in the first X rows.
                    int iRow;
                    DataRow DataRow;
                    for (iRow = 0; iRow <= NumberOfRowsToScan - 1; iRow++)
                    {
                        DataRow = DataTable.Rows[iRow];
                        if (!IsDBNull(DataRow[Column.ColumnName]))
                            Width = (int)Math.Max(Width, Graphics.MeasureString(DataRow[Column.ColumnName].ToString(), DataGrid.Font, MaxPixelWidth).Width);
                    }
                    ColumnStyle.Width = Width + 4;
                    // Add the new column style to the table style.
                    TableStyle.GridColumnStyles.Add(ColumnStyle);
                }
                // Add the new table style to the data grid.
                DataGrid.TableStyles.Add(TableStyle);
                // Resize Last Column
                var intNumCols = ((DataTable)DataGrid.DataSource).Columns.Count;
                var intTargetWidth = DataGrid.ClientSize.Width - SystemInformation.VerticalScrollBarWidth - 4;
                var intRunningWidthUsed = DataGrid.TableStyles[DataTable.TableName].RowHeaderWidth;
                for (var ii = 1; ii <= intNumCols - 1; ii++)
                    intRunningWidthUsed += DataGrid.TableStyles[DataTable.TableName].GridColumnStyles[ii - 1].Width;
                if ((intRunningWidthUsed < intTargetWidth))
                    DataGrid.TableStyles[DataTable.TableName].GridColumnStyles[intNumCols - 1].Width = intTargetWidth - intRunningWidthUsed;
            }
            finally
            {
                Graphics.Dispose();
            }
            return TableStyle;
        }

Is there anything you can spot that has changed since preview 5, that could cause such an issue? As it doesn't seem to be being caused by the AutoScaleBaseSize unlike the rest.

Also is there a list anywhere that we can see all the things that have changed regarding UI for core 3? Almost all of the winforms apps we have that need converting are very old (most never went past .net 1) so having all the things to check in one place would be much appreciated.

[RussKie]

There is one other major UI issue we have noticed since going past preview 5. We have a DataGrid that applies a table style which resizes the columns based on the content. Once going past preview 5, any forms with this DataGridTableStyle hang upon first load and cause the form to flicker, however if you then close the form and reopen it again the form loads and works correctly.

Please raise a new issue providing as much information as possible and a repro app, and we'll have a look at it.

[RussKie]

Also is there a list anywhere that we can see all the things that have changed regarding UI for core 3?

I don't think there is a document avialable that lists all changes.
You can browse issues fixed/changes accepted in each milestone:

• Preview 4
• Preview 5
• Preview 6
• Preview 7
• Preview 8
• Preview 9

For the most part Windows Forms on .NET Core 3.0 is about providing an API parity with the .NET Framework (4.7.2/4.8) and porting missing bits and pieces. It is possible that few APIs are still missing, but based on the data we have collected those API weren't widely used.
Another significant area of focus for us was increasing an automated test coverage to reduce the load on our testing team.

Also it is worth noting that a number of changes have been made down in the stack (i.e. in the CoreFx and CoreCLR) which we have little-to-no visibility of, and thus things can break unbeknown to us (e.g. #242).
I know it is of little comfort to our users, but it is what it is.

And lastly, if you think something is broken in our code (not totally impossible) and it is blocking you, you can pull this repo down, run .\build-local.ps1, refernce the built assets and step through the code to see what isn't working as expected.
Contributions are quite welcome 😉

[CodedBeard]

Thanks @RussKie.

I'll open another issue if I can't find what’s causing the grid problem, but its a lot harder to make a clean repro for, so will have a bit more of a dig first. Just thought I’d check it wasn't anything obviously wrong in that code along the same lines.

For the most part Windows Forms on .NET Core 3.0 is about providing an API parity with the .NET Framework (4.7.2/4.8) and porting missing bits and pieces.

Yep completely understand. I've been really impressed with just how little has gone wrong considering this app hasn't been updated in almost 15 years. Awesome job by the team!

And lastly, if you think something is broken in our code (not totally impossible) and it is blocking you, you can pull this repo down, run .\build-local.ps1, refernce the built assets and step through the code to see what isn't working as expected.

Point taken. Despite having been using core since the dnx days, I still forget that that’s an option :)

[merriemcgaw]

@CodedBeard if you've got what you need with this issue, I'm going to go ahead and close it.

[RussKie]

It is worth noting that AutoScaleDimensions can yield unexpected results as well - #1948 (comment).