Update dispose-pattern.md (#6114)

* Add C# code highlighting
* Fix whitespace

Author: yauhenipakala

docs/standard/design-guidelines/dispose-pattern.md

@@ -53,22 +53,22 @@ All programs acquire one or more system resources, such as memory, system handle
 
  The following example shows a simple implementation of the basic pattern:  
 
-```  
+```csharp
 public class DisposableResourceHolder : IDisposable {  
 
     private SafeHandle resource; // handle to a resource  
   
-    public DisposableResourceHolder(){  
+    public DisposableResourceHolder() {  
         this.resource = ... // allocates the resource  
     }  
 
-    public void Dispose(){  
+    public void Dispose() {  
         Dispose(true);  
         GC.SuppressFinalize(this);  
     }  
 
-    protected virtual void Dispose(bool disposing){  
-        if (disposing){  
+    protected virtual void Dispose(bool disposing) {  
+        if (disposing) {  
             if (resource!= null) resource.Dispose();  
         }  
     }  
@@ -83,9 +83,9 @@ public class DisposableResourceHolder : IDisposable {
 
  All resource cleanup should occur in this method. The method is called from both the finalizer and the `IDisposable.Dispose` method. The parameter will be false if being invoked from inside a finalizer. It should be used to ensure any code running during finalization is not accessing other finalizable objects. Details of implementing finalizers are described in the next section.  
 
-```  
-protected virtual void Dispose(bool disposing){  
-    if (disposing){  
+```csharp
+protected virtual void Dispose(bool disposing) {  
+    if (disposing) {  
         if (resource!= null) resource.Dispose();  
     }  
 }  
@@ -95,7 +95,7 @@ protected virtual void Dispose(bool disposing){
 
  The call to `SuppressFinalize` should only occur if `Dispose(true)` executes successfully.  
 
-```  
+```csharp
 public void Dispose(){  
     Dispose(true);  
     GC.SuppressFinalize(this);  
@@ -106,17 +106,17 @@ public void Dispose(){
 
  The `Dispose(bool)` method is the one that should be overridden by subclasses.  
 
-```  
+```csharp
 // bad design  
 public class DisposableResourceHolder : IDisposable {  
-    public virtual void Dispose(){ ... }  
-    protected virtual void Dispose(bool disposing){ ... }  
+    public virtual void Dispose() { ... }  
+    protected virtual void Dispose(bool disposing) { ... }  
 }  
 
 // good design  
 public class DisposableResourceHolder : IDisposable {  
-    public void Dispose(){ ... }  
-    protected virtual void Dispose(bool disposing){ ... }  
+    public void Dispose() { ... }  
+    protected virtual void Dispose(bool disposing) { ... }  
 }  
 ```  
 
@@ -126,13 +126,13 @@ public class DisposableResourceHolder : IDisposable {
 
  **✓ DO** allow the `Dispose(bool)` method to be called more than once. The method might choose to do nothing after the first call.  
 
-```  
+```csharp
 public class DisposableResourceHolder : IDisposable {  
 
     bool disposed = false;  
 
-    protected virtual void Dispose(bool disposing){  
-        if(disposed) return;  
+    protected virtual void Dispose(bool disposing) {  
+        if (disposed) return;  
         // cleanup  
         ...  
         disposed = true;  
@@ -148,18 +148,18 @@ public class DisposableResourceHolder : IDisposable {
 
  **✓ DO** throw an <xref:System.ObjectDisposedException> from any member that cannot be used after the object has been disposed of.  
 
-```  
+```csharp
 public class DisposableResourceHolder : IDisposable {  
     bool disposed = false;  
     SafeHandle resource; // handle to a resource  
   
-    public void DoSomething(){  
-           if(disposed) throw new ObjectDisposedException(...);  
+    public void DoSomething() {  
+        if (disposed) throw new ObjectDisposedException(...);  
         // now call some native methods using the resource   
-            ...  
+        ...  
     }  
-    protected virtual void Dispose(bool disposing){  
-        if(disposed) return;  
+    protected virtual void Dispose(bool disposing) {  
+        if (disposed) return;  
         // cleanup  
         ...  
         disposed = true;  
@@ -171,12 +171,12 @@ public class DisposableResourceHolder : IDisposable {
 
  When doing so, it is important that you make the `Close` implementation identical to `Dispose` and consider implementing the `IDisposable.Dispose` method explicitly.  
 
-```  
+```csharp
 public class Stream : IDisposable {  
-    IDisposable.Dispose(){  
+    IDisposable.Dispose() {  
         Close();  
     }  
-    public void Close(){  
+    public void Close() {  
         Dispose(true);  
         GC.SuppressFinalize(this);  
     }  
@@ -195,29 +195,29 @@ public class Stream : IDisposable {
 
  The following code shows an example of a finalizable type:  
 
-```  
+```csharp
 public class ComplexResourceHolder : IDisposable {  
 
     private IntPtr buffer; // unmanaged memory buffer  
     private SafeHandle resource; // disposable handle to a resource  
   
-    public ComplexResourceHolder(){  
+    public ComplexResourceHolder() {  
         this.buffer = ... // allocates memory  
         this.resource = ... // allocates the resource  
     }  
 
-    protected virtual void Dispose(bool disposing){  
+    protected virtual void Dispose(bool disposing) {  
             ReleaseBuffer(buffer); // release unmanaged memory  
-        if (disposing){ // release other disposable objects  
+        if (disposing) { // release other disposable objects  
             if (resource!= null) resource.Dispose();  
         }  
     }  
 
-    ~ ComplexResourceHolder(){  
+    ~ComplexResourceHolder() {
         Dispose(false);  
     }  
 
-    public void Dispose(){  
+    public void Dispose() {
         Dispose(true);  
         GC.SuppressFinalize(this);  
     }  
@@ -236,14 +236,14 @@ public class ComplexResourceHolder : IDisposable {
 
  When implementing the finalizer, simply call `Dispose(false)` and place all resource cleanup logic inside the `Dispose(bool disposing)` method.  
 
-```  
+```csharp
 public class ComplexResourceHolder : IDisposable {  
 
-    ~ ComplexResourceHolder(){  
+    ~ComplexResourceHolder() {
         Dispose(false);  
     }  
 
-    protected virtual void Dispose(bool disposing){  
+    protected virtual void Dispose(bool disposing) {
         ...  
     }  
 }