B4A只能在Globals和Process_Globals中定义

Sub
定义一个过程，包括参数和返回值(可选)
语法:
Sub name [(list of parameters)] [As return-type]
参数包括参数名和类型.
数组参数的维度不能包含在内.
例如:
Sub MySub (FirstName As String, LastName As String, Age As Int, OtherValues() As
Double) As Boolean
...
End Sub
在这个例子中OtherValues 是一个一维数组
返回类型如果是数组的话，需要括号
TAB As String
制表符.
Tan (Radians As Double) As Double
TanD (Degrees As Double) As Double
ToastMessageShow (Message As String, LongDuration As Boolean)
显示一个简短的消息并自动消失
Message - 需要显示的文本消息.
LongDuration - 如果设置为true,显示时间将会稍微长一点
True As Boolean
Try
Any exception thrown inside a try block will be caught in the catch block.
任何异常都需要在一个try模块中被抛出，并在catch模块中捕获
调用LastException 可以获取捕获的异常
语法:
Try
...
Catch
...
End Try
Type
定义一个结构体.
只能在Globals和Process_Globals中定义
语法:
Type type-name (field1, field2, ...)
Fields 包括名称和变量类型.
例如:
Type MyType (Name As String, Items(10) As Int)
Dim a, b As MyType
a.Items(2) = "very interesting item"
Until
循环执行，直到条件为真
语法:
Do Until condition