添加、删除标签以及窗体间参数的传递

 

这是在实现Arcgis Engine的书签的添加以及读取时接触到的：点击添加标签后，弹出给标签命名的窗体，输入名称后将该名字添加到另一个标签列表的窗体。在主对话框分别实现存储和读取的接口。

主窗体的实现的代码如下：

Private Sub 添加书签ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 存为书签ToolStripMenuItem.Click
        Dim pMapBookmarks As IMapBookmarks
        pMapBookmarks = AxMapControl1.ActiveView.FocusMap
        Dim pAOIBookmark As IAOIBookmark
        pAOIBookmark = New AOIBookmark
        pAOIBookmark.Location = AxMapControl1.ActiveView.Extent


        Dim Bookmark As New Bookmark
        'Dim pBMname As String
        ' Bookmark.MdiParent = Me
        Bookmark.ShowDialog()
        'My.Forms.Bookmark.Bookmark_Load(sender, e)

        If pBookmarkName IsNot Nothing Then
            pAOIBookmark.Name = pBookmarkName

            pMapBookmarks.AddBookmark(pAOIBookmark)

        End If

    End Sub

    Private Sub 打开书签ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 打开书签ToolStripMenuItem.Click
        Dim pMapBookmarks As IMapBookmarks
        pMapBookmarks = CType(AxMapControl1.ActiveView.FocusMap, IMapBookmarks)
        Dim pEnumSpatialBM As IEnumSpatialBookmark
        pEnumSpatialBM = pMapBookmarks.Bookmarks


        BookmarkList.ShowDialog()
        Dim pOpenBMname As String
        pOpenBMname = OpenBMname

        Dim pSpatialBM As ISpatialBookmark
        pSpatialBM = pEnumSpatialBM.Next
        While (pSpatialBM IsNot Nothing)

            If pSpatialBM.Name = pOpenBMname Then
                pSpatialBM.ZoomTo(AxMapControl1.ActiveView.FocusMap)
                AxMapControl1.ActiveView.Refresh()
                Return
            End If
            pSpatialBM = pEnumSpatialBM.Next
        End While
      

    End Sub
End Class

添加书签窗体的代码如下：

Public BookmarkList As New BookmarkList
    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        pBookmarkName = TextBox1.Text
    End Sub

    Public Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'My.Forms.MainForm.BMname = TextBox1.Text
        pBookmarkName = TextBox1.Text
        My.Forms.MainForm.BookmarkList.additem(pBookmarkName)
        Me.Hide()
    End Sub

书签窗体代码

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer
        i = ComboBox1.Items.Count
        My.Forms.MainForm.OpenBMname = ComboBox1.Text
        Me.Hide()
    End Sub

        Public Sub additem(ByVal BookmarkName As String)
        ComboBox1.Items.Add(BookmarkName)
    End Sub

其中pBookmarkName是在新建的模块中定义的公共变量。

在书签的过程中，主要实现不同窗体间参数的传递。传递方法是：（假如form2 textbox的值向form1的字符串变量m传递）

方法一：

定义模块变量str

form2窗体：

str=textbox.text

form1窗体：

m=str

方法二：

在form1中定义公共变量：

public str as string

Private sub ButtonOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonOK.Click

str=textbox.text

End sub

在form2中

直接调用a=My.Forms.Form2.str

还有一个问题是:显示标签对话框时，用Form2.ShowDialog()而不是Form2.Show()。用后者会运行程序时，运行到Form2.show（），并没有完全弹出Form2,程序也没有调到Form2中，而是继续往下。改成ShowDialog是可以解决问题，可是不知道为什么……哪位知道指点一下哦~