In the following this simple code, for example:

Dim f () as a double
Dim h () as a double

Private Sub Command1_Click () ', 'this is a computational process
Redim f (2, 2)
Redim h (2, 2)
"' comes from an excel f
H=f
End sub

Private Sub Command2_Click ()
If h is an empty array then
Msgbox "error: did not calculate, please recalculate"
The else
H into another form
End the if
End sub

Excuse me each great god , who know how to realize the function of Command2, main problem of determining an empty array,

CodePudding user response:

 
Private Sub Command1_Click () 
Dim (f) As String 
If CheckNull (f) Then MsgBox "empty" Else MsgBox "not empty" 
ReDim f (1) 
If CheckNull (f) Then MsgBox "empty" Else MsgBox "not empty" 
ReDim f (1, 1) 
If CheckNull (f) Then MsgBox "empty" Else MsgBox "not empty" 
Erase f 
If CheckNull (f) Then MsgBox "empty" Else MsgBox "not empty" 
End Sub 
'check empty array 
Private Function CheckNull (aryIn As the Variant) As Boolean 
On Error GoTo errhandle 
Dim As Long a 
A=LBound (aryIn) 
CheckNull=False 
The Exit Function 
Errhandle: 
CheckNull=True 
End the Function 

CodePudding user response:

 
Private Declare Function VarPtr Lib "msvbvm60. DLL" (ByRef Ptr () As Any) As Long 
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any Source, As Any, ByVal Length As Long) 
The Public Function IsEmptyArray (Arr () As Double) As Boolean 
Dim the Result As Long 
CopyMemory Result, ByVal VarPtr (Arr), 4 
IsEmptyArray=CBool (Result=0) 
End the Function 

CodePudding user response:

To determine whether a dynamic array initialization
Dim MyArray on () As String, NumberOfElements As Long

If (Not MyArray on)=1 Then
NumberOfElements=0 'The array is uninitialised
The Else
NumberOfElements=UBound (MyArray on) + 1
End the If

CodePudding user response:

With the API:
'API to determine the array is empty or not initialized
Private Declare Function SafeArrayGetDim Lib "oleaut32. DLL" (ByRef saArray () As Any) As Long
The value of 0 indicates an uninitialized

CodePudding user response:

The

reference 3 floor zzyong00 response:

to determine whether a dynamic array initialization
Dim MyArray on () As String, NumberOfElements As Long

If (Not MyArray on)=1 Then
NumberOfElements=0 'The array is uninitialised
The Else
NumberOfElements=UBound (MyArray on) + 1
End the If

Before learning. Have been using the API. This seems very good... From discovering the new continent..

CodePudding user response:

 Private Sub Command2_Click () 
Dim I, j, k, num As Integer 'I, j, k is the intermediate variable, num is to determine the size of the matrix (a few specific *) 
Num=UBound (a) * UBound (a, 2) 
For I=0 To UBound (a) - 1 'starting from 1 d 
For j=0 To UBound (a, 2) - 1 '2 dimension To judge 
If a (I, j)="" Then k=k + 1 'record the number of empty 
Next 
Next 
If k=num Then is' judgment matrix is null 
Msgbox "error: did not calculate, please recalculate" : the exit sub 
The else 
'

h into another form
End sub
[/code]

CodePudding user response:

refer to 6th floor qq_42927700 response:

 Private Sub Command2_Click () 
Dim I, j, k, num As Integer 'I, j, k is the intermediate variable, num is to determine the size of the matrix (a few specific *) 
Num=UBound (a) * UBound (a, 2) 
For I=0 To UBound (a) - 1 'starting from 1 d 
For j=0 To UBound (a, 2) - 1 '2 dimension To judge 
If a (I, j)="" Then k=k + 1 'record the number of empty 
Next 
Next 
If k=num Then is' judgment matrix is null 
Msgbox "error: did not calculate, please recalculate" : the exit sub 
The else 
'

h into another form
End sub
[/code]

You dig a grave,
When the array is empty UBound return value may be 1, may be an error,
This code or you have any question,

CodePudding user response:

In setting a judgment with the location of the array,

CodePudding user response:

refer to the eighth floor zhanghaaaa response:

set in an array with the location of a judgment,

You still read a few years to say again...