vb.net OpenFileDialog.ShowDialog 多种实例代码和注释

以下是几个VB.NET中 OpenFileDialog.ShowDialog 方法的实例代码和注释：

1. 基本用法：

Dim openFileDialog1 As New OpenFileDialog()

openFileDialog1.Filter = "Text Files|*.txt"
openFileDialog1.Title = "Select a Text File"

If openFileDialog1.ShowDialog() = DialogResult.OK Then
    ' 用户选择了一个文件
End If

2. 打开文件夹：

Dim folderBrowserDialog1 As New FolderBrowserDialog()

If folderBrowserDialog1.ShowDialog() = DialogResult.OK Then
    ' 用户选择了一个文件夹
End If

3. 多选文件：

Dim openFileDialog1 As New OpenFileDialog()

openFileDialog1.Multiselect = True
openFileDialog1.Filter = "Text Files|*.txt"
openFileDialog1.Title = "Select Text Files"

If openFileDialog1.ShowDialog() = DialogResult.OK Then
    ' 用户选择了一个或多个文件
    For Each file As String In openFileDialog1.FileNames
        ' 处理每个文件
    Next
End If

4. 指定初始目录：

Dim openFileDialog1 As New OpenFileDialog()

openFileDialog1.InitialDirectory = "C:\Users\Public\Documents"
openFileDialog1.Filter = "Text Files|*.txt"
openFileDialog1.Title = "Select a Text File"

If openFileDialog1.ShowDialog() = DialogResult.OK Then
    ' 用户选择了一个文件
End If

5. 自定义按钮文本：

Dim openFileDialog1 As New OpenFileDialog()

openFileDialog1.Filter = "Text Files|*.txt"
openFileDialog1.Title = "Select a Text File"
openFileDialog1.CustomPlaces.Add("C:\Users\Public\Documents")

' 自定义按钮文本
openFileDialog1.CustomPlaces.Add(New FileDialogCustomPlace("My Documents", "::{450D8FBA-AD25-11D0-98A8-0800361B1103}"))

If openFileDialog1.ShowDialog() = DialogResult.OK Then
    ' 用户选择了一个文件
End If

上述代码中的注释可以帮助您更好地理解 OpenFileDialog.ShowDialog 方法的使用。