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Suppose your VB6 has this:
| Code Block | ||
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SysInfo control on a Form ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >1301 Begin SysInfoLib.SysInfo SysInfo1 1302 Left = 13920 1303 Top = 0 1304 _ExtentX = 1005 1305 _ExtentY = 1005 1306 _Version = 393216 1307 End ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Logic to use SysInfo control to get ScrollBarSizwe ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 8014 Private Function XSizePartsUpDown() ... >8020 .Width = SysInfo1.ScrollBarSize ... 8024 End With 8025 End Function |
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We wish to change a control instance property declared in a COM interface description file (IDF) to a static readonly property declared in a .NET framework class.
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Here is the property in the COM IDF
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
proj\idf\FromIdl\SYSINFO.OCX.xml
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
17 <class id="ISysInfo" parent="IDispatch">
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> 26 <property id="ScrollBarSize" type="Single" status="Out"/>
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32 </class>
And, here is the replacement property in WinForms:
//
// Summary:
// Gets the default width, in pixels, of the vertical scroll bar.
//
// Returns:
// The default width, in pixels, of the vertical scroll bar.
public static int VerticalScrollBarWidth { get; }
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The recommended way to migrate a COM API is to use a RefactorLibrary file. A RefactorLibrary is a set of migration rules that direct how the translator interprets and rewrites code relating to a COM API. Here is the stub RefactorLibrary file to get us started:
| Code Block | ||
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<RefactorLibrary> <Refactor id="[SYSINFO.OCX]"> ... rules will go here ... </Refactor> </RefactorLibrary> |
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References to SysInfo.ocx cause gmStudio to load the SysInfo.ocx.xml interface description. If there is a MigFile registered, then gmStudio will also load the RefactorLibrary and modify the SysInfo API description information. Here is an excerpt from the translation log:
| Code Block | ||
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Loading reference:[SYSINFO.OCX] ...\proj\idf\FromIdl\SYSINFO.OCX.xml Loading reference:[SYSINFO.OCX.WinForms.Refactor] ...\proj\usr\SYSINFO.OCX.WinForms.Refactor.xml |
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proj\usr\SYSINFO.OCX.WinForms.Refactor.xml
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<Refactor id="[SYSINFO.OCX]">
Rule 1) <Migrate location="DoNotDeclace" libType="Internal" />
Rule 2) <Migrate id="SysInfo" role="define" migName="SysInfo" />
Rule 3) <Migrate id="ISysInfo.ScrollBarSize" type="Integer" refType="Method" migPattern="System.Windows.Forms.SystemInformation.VerticalScrollBarWidth" nPram="1"/>
Rule 4) <migClass id="NetControl.SysInfo" migName="Remove.SysInfo" parent="SysInfo">
<!-- Suppress designer code -->
</migClass>
</Refactor>
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Rule 3) This tells the tool to migrate references to property ScrollBarSize as System.Windows.Forms.SystemInformation.VerticalScrollBarWidth:
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NOT THAT: .Width = SysInfo1.ScrollBarSize BUT THIS: .Width = System.Windows.Forms.SystemInformation.VerticalScrollBarWidth |
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