Sorry your browser is not supported!

Private mutDBP As New Threading.Mutex(False, "DBP")
Private mutVB As New Threading.Mutex(True, "VB")

    Private Sub TmrMutex_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrMutex.Tick

        If mutDBP.WaitOne(0, False) = True Then
            tmrMutex.Stop()
            MsgBox("Connection to Child Application lost")
            ' *** Put some user-friendly handling here if applicable
            End
        End If

    End Sub

try
{
	if(mutDBP.WaitOne(1, false)) // Will throw an error if it is abandoned
	{
		throw new Exception(""); // If we get the mutex throw an error
	}
}
catch (Exception e)
{
	// DBP App is closed
	MessageBox.Show("Connection to Child Application lost");
        // *** Put some user-friendly handling here if applicable
        System.Exit(0);
}

.method private hidebysig instance void Form1_Load(object sender, class [mscorlib]System.EventArgs e) cil managed
{
    .maxstack 1
    .locals init (
        [0] class OnErrorCTest.Form1 form,
        [1] class [mscorlib]System.Exception err)
    L_0000: nop 
    L_0001: nop 
    L_0002: ldnull 
    L_0003: stloc.0 
    L_0004: ldloc.0 
    L_0005: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Control::get_Text()
    L_000a: call void [mscorlib]System.Console::WriteLine(string)
    L_000f: nop 
    L_0010: nop 
    L_0011: leave.s L_0018
    L_0013: stloc.1 
    L_0014: nop 
    L_0015: nop 
    L_0016: leave.s L_0018
    L_0018: nop 
    L_0019: ret 
    .try L_0001 to L_0013 catch [mscorlib]System.Exception handler L_0013 to L_0018
}

.method private instance void Form1_Load(object sender, class [mscorlib]System.EventArgs e) cil managed
{
    .maxstack 3
    .locals init (
        [0] class OnErrorTest.Form1 form,
        [1] int32 VB$ActiveHandler,
        [2] int32 VB$ResumeTarget,
        [3] int32 VB$CurrentStatement)
    L_0000: nop 
    L_0001: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::ClearProjectError()
    L_0006: ldc.i4.s -2
    L_0008: stloc.1 
    L_0009: ldc.i4.2 
    L_000a: stloc.3 
    L_000b: ldloc.0 
    L_000c: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Form::get_Text()
    L_0011: call void [mscorlib]System.Console::WriteLine(string)
    L_0016: nop 
    L_0017: leave.s L_007d
    L_0019: ldloc.2 
    L_001a: br.s L_001f
    L_001c: ldloc.2 
    L_001d: ldc.i4.1 
    L_001e: add 
    L_001f: ldc.i4.0 
    L_0020: stloc.2 
    L_0021: switch (L_0036, L_0001, L_0009, L_0017)
    L_0036: leave.s L_0072
    L_0038: ldloc.3 
    L_0039: stloc.2 
    L_003a: ldloc.1 
    L_003b: ldc.i4.s -2
    L_003d: bgt.s L_0042
    L_003f: ldc.i4.1 
    L_0040: br.s L_0043
    L_0042: ldloc.1 
    L_0043: switch (L_0050, L_001c)
    L_0050: leave.s L_0072
    L_0052: isinst [mscorlib]System.Exception
    L_0057: ldnull 
    L_0058: cgt.un 
    L_005a: ldloc.1 
    L_005b: ldc.i4.0 
    L_005c: cgt.un 
    L_005e: and 
    L_005f: ldloc.2 
    L_0060: ldc.i4.0 
    L_0061: ceq 
    L_0063: and 
    L_0064: endfilter 
    L_0066: castclass [mscorlib]System.Exception
    L_006b: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::SetProjectError(class [mscorlib]System.Exception)
    L_0070: leave.s L_0038
    L_0072: ldc.i4 -2146828237
    L_0077: call class [mscorlib]System.Exception [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::CreateProjectError(int32)
    L_007c: throw 
    L_007d: nop 
    L_007e: ldloc.2 
    L_007f: brfalse.s L_0086
    L_0081: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::ClearProjectError()
    L_0086: ret 
    .try L_0001 to L_0052 filter L_0052 handler L_0066 to L_0072
}