Changes between Initial Version and Version 1 of Using

Timestamp:

05/05/10 11:09:13 (15 years ago)

Author:

hopscc

Comment:

--

Using

@@ +1 @@
+= Using = 
+
+Allows  IDisposable object acquisition and defines a scope outside of which the the object will be 
+disposed in the correct manner.[[BR]]
+This provides a convenient structure that encapsulates the 
+correct use and release of an IDisposable object.
+
+The idiom is that an IDisposable object  is acquired/constructed in the '''using''' 
+statement expression, assigned to a local variable and used within the block. [[BR]]
+When the block terminates (for '''any''' reason, fall through, exception or return)
+the using statement calls the .dispose  method on the object in the correct way,[[BR]] 
+and also causes the object itself to go out of scope as soon as .dispose is called. [[BR]]
+Within the using block, the object is read-only and cannot be modified or reassigned.
+
+== Grammar ==
+{{{
+using <name> = <expression> 
+    BLOCK
+}}}
+
+== Platform ==
+
+The above description is couched in terms of .Net 
+(IDisposable interface, objects supporting a .dispose method for resource release/cleanup).
+
+The effect is translated to a similarly releasable interface on other platforms.
+  * Java: 
+
+== Examples ==
+
+{{{
+using font1 = new Font("Arial", 10.0f) 
+    charset = font1.GdiCharSet
+    # do domething with charset
+# font1 disposed of (and out of scope) here
+}}}
+
+
+{{{
+using f = File.createText(scriptName)
+    f.writeLine('#!/bin/sh')
+    f.writeLine('echo "Running a shell script made from cobra-[CobraCore.version]" "$@"')
+}}}
+
+{{{
+using resultsWriter = File.appendText(resultsFileName)
+    print to resultsWriter, 'Results of Run [date]'
+    .printTotals(resultsWriter to !)
+}}}
+
+== Notes ==
+
+You can achieve a similar result by putting the object inside a try
+block and then calling .dispose in a finally block
+{{{
+  font1 = new Font("Arial", 10.0f)
+  try
+    charset = font1.GdiCharSet
+    # do domething with charset
+  finally
+    if font1, (font1 to IDisposable).dispose
+}}}
+
+== See Also ==
+see [http://msdn.microsoft.com/en-us/library/yh598w02.aspx using statement (C# reference)]
+