为什么当我处理表单并再次返回时 openFileDialog 没有响应？答案

【问题标题】：Why openFileDialog doesn't responding when i dispose the form and back to it again?为什么当我处理表单并再次返回时 openFileDialog 没有响应？
【发布时间】：2020-03-25 04:52:52
【问题描述】：

我在一个表单中有两个 openFileDialog 工具，当我浏览 openFileDialog1 并选择一张图片时，没关系，但是当我处理此表单并返回它并单击以浏览另一张图片，它没有响应，项目停止，没有错误！！！

    Private Sub Browse_Click(sender As Object, e As EventArgs) Handles Browse.Click
        OpenFileDialog1.FileName = ""
        OpenFileDialog1.Filter = "Image Files (*.jpg, *.bmp, *.gif, *.png)|*.jpg; *.bmp; *.gif; *.png"
        If OpenFileDialog1.FileName = "" Then
            If OpenFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
                txtFileName.Text = OpenFileDialog1.FileName
                txtFileName.SelectionStart = txtFileName.Text.Length 'to show the last portion of text
                If Trim(txtFileName.Text) <> "" Then picSave.Image = Image.FromFile(txtFileName.Text)
            End If
        Else
            Exit Sub
        End If
    End Sub

    Private Sub Btnclose_Click(sender As Object, e As EventArgs) Handles Btnclose.Click
        Me.Dispose()
    End Sub

【问题讨论】：

Me.Close()。这有什么意义：If OpenFileDialog1.FileName = "" Then ... 当您在检查之前设置 OpenFileDialog1.FileName = "" 时？顺便说一句，您可以在需要时创建一个 OpenFileDialog 对象：using ofd as new OpenFiledialog (...) end using

标签： vb.net

【解决方案1】：

在项目属性中，确保您已将关闭模式设置为“当最后一个表单关闭时”。这不是默认设置。

在表格 1 中

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    OpenFileDialog1.Filter = "Image Files (*.jpg, *.bmp, *.gif, *.png)|*.jpg; *.bmp; *.gif; *.png"
    If OpenFileDialog1.ShowDialog() = DialogResult.OK Then
        TextBox1.Text = OpenFileDialog1.FileName
        PictureBox1.Image = Image.FromFile(TextBox1.Text)
    End If
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Form2.Show()
    Close()
End Sub

然后在Form2中

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Form1.Show()
    Close()
End Sub

当我返回 Form1 时，OpenFileDialog 行为正常。

【讨论】：