vb.net简单计算错误

vb.net简单计算错误，代码如下：

Public Class Form1
  Dim qiu As Integer = 0, jin As Integer = 0, ming As Integer
  Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
  TextBox1.Text = qiu
  TextBox2.Text = jin
  End Sub

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  ming = qiu + jin
  End Sub

  Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
  ming = qiu - jin

  End Sub

  Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
  ming = qiu * jin

  End Sub

  Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
  ming = qiu / jin

  End Sub

  Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
  Label1.Text = ming
  End Sub
End Class

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注意类型，textbox里来的是字符型 ，要计算就要转换一下。
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Ctype(TextBox1.Text.Trim,Integer)
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qiu 和jin都是0，其他地方也没有赋值，做除法运算的话肯定会出错

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探讨

qiu 和jin都是0，其他地方也没有赋值，做除法运算的话肯定会出错

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Dim qiu As Integer = 0, jin As Integer = 0
TextBox1.Text = qiu
TextBox2.Text = jin


0+0=?
0-0=?
0*0=?
0/0=?

全是0，你想=？
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qiu ,jin 变量没看到在计算前赋值，怎么可能有结果呢，如果没看错，Button5应该是等于按钮吧，在这个地方赋值没有任何作用，这个程序更本没有任何实际操作吗，你可以把qiu = CInt(TextBox1.Text)
jin = CInt(TextBox2.Text) 这两句代码在每个Button的click事件都加下，如果文本框中的数据不会导致异常，肯定有效果，不过就这个程序本身来说，只能说你还有很多要学

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