Do...Loop 语句
Repeats the statements between the Do and the Loop statement while the condition is True or until the condition becomes True.
Do {While | Until} condition = True
' Do While: The statement block is repeated as long as the condition is true
' Do Until: The statement block is repeated as long as the condition is false
statements
[Exit Do]
statements
Loop
Do
statements
[Exit Do]
statements
' Loop While: The statement block repeats as long as the condition is true
' Loop Until: The statement block repeats until the condition is true
Loop {While | Until} condition = True
The Do...Loop statement executes a loop as long as, or until, a certain condition is True. The condition for exiting the loop must be entered following either the Do or the Loop statement. The above examples are valid combinations.
condition: A comparison, numeric or Basic expression, that evaluates to either True or False.
statements: Statements that you want to repeat while or until a condition is True.
「Exit Do」语句可用于无条件地结束循环。您可以在「Do...Loop」语句中的任意位置加入此语句。此外，也可以使用「If...Then」结构定义一个退出条件:
Do...
statements
If condition = True Then Exit Do
statements
Loop...
Sub ExampleDoLoop
Dim sFile As String
Dim sPath As String
sPath = "c:\"
sFile = Dir$( sPath ,22)
If sFile <> "" Then
Do
MsgBox sFile
sFile = Dir$
Loop Until sFile = ""
End If
End Sub