实现效果:

知识运用:
DirectoryInfo类的Create方法
string对象的EndsWith方法
实现代码:
private void button1_Click(object sender, EventArgs e)
{
FolderBrowserDialog FBDialog = new FolderBrowserDialog();
if (FBDialog.ShowDialog() == DialogResult.OK)
{
string strPath=FBDialog.SelectedPath;
if (strPath.EndsWith("\"))
textBox1.Text = strPath;
else
textBox1.Text = strPath + "\";
}
}
private void button2_Click(object sender, EventArgs e)
{
DirectoryInfo Dinfo = new DirectoryInfo(textBox1.Text+textBox2.Text);
Dinfo.Create();
}