请问各位，TextBox控件的SelStart, SelLength属性的意思分别是什么啊？
我查手册，查不到这个两个属性的意思！
请知道的朋友帮忙解释一下好吗？谢谢！

这个是MSDN里的：

SelLength, SelStart, SelText
The SelLength property returns or sets the number of characters selected.

The SelStart property returns or sets the starting point of text selected; indicates the position of the insertion point if no text is selected.

The SelText property returns or sets the string containing the currently selected text; consists of a zero-length string ("") if no characters are selected.

Note These properties are not available at design time.

Syntax
object.SelLength [= number]

object.SelStart [= index]

object.SelText [= value]

The parts of the SelLength, SelStart, and SelText property syntaxes are described in the following table.

Part Description
object An object expression that evaluates to an object.
number A numeric expression specifying the number of characters selected. For SelLength and SelStart, the valid range of settings is 0 to text length — the total number of characters in the edit area of a ComboBox or TextBox control.
index A numeric expression specifying the starting point of the selected text, as described in Settings.
value A string expression containing the selected text.

Remarks
Use these properties for tasks such as setting the insertion point, establishing an insertion range, selecting substrings in a control, or clearing text. Used in conjunction with the Clipboard object, these properties are useful for copy, cut, and paste operations.

When working with these properties, remember that:

Setting SelLength less than 0 causes a run-time error.
Setting SelStart greater than the text length sets the property to the existing text length; changing SelStart changes the selection to an insertion point and sets SelLength to 0.
Setting SelText to a new value sets SelLength to 0 and replaces the selected text with the new string.

给你段中文的：
SelLength 返回或设置 Slider 控件中选择出的范围长度。

SelStart 返回或设置 Slider 控件中选择出的范围起点。
语法

object.SelLength [= value]

object.SelStart [= value]

SelLength 和 SelStart 属性的语法包含下面部分：

部分 描述
object 对象表达式，其值是 Slider 控件。
value Min 和 Max 属性中的数值。

说明

SelLength 和 SelStart 属性一起使用，可以在 Slider 控件上选择某一范围内的连续数值。于是，Slider 控件还具有进一步的优势，它可以在直观上模拟可能的取值范围。

SelLength 属性不能小于 0，SelLength 与 SelStart 之和不能大于 Max 属性。

注意:对中文支持不好。

谢谢楼上的朋友！昨晚停电，所以没法上来看！充心感谢!