[填空题] 在窗体上画1个命令按钮和1个文本框,其名称分别为Command1和Text1,然后编写如下代码:Dim SaveAll As StringPrivate Sub Command1 Click()Text1.Text=Left(UCase(SaveAll),4)End SubPrivate Sub Text1_KeyPress(KeyAscii As Integer)SaveAll=SaveAll+Chr(KeyAscii)End Sub程序运行后,在文本框中输入abcdefg,单击命令按钮,则文本框中显示的内容是()。