Private WithEvents _WebClient As New System.Net.WebClient
...
'--------------------------------------------------------------------------------
'「ダウンロード開始」ボタンクリック
'--------------------------------------------------------------------------------
Private Sub btnDownload_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnDownload.Click
''入力項目チェック
If (txtDownloadUrl.Text.Length = 0) Then
MessageBox.Show("ダウンロードURLを入力してください。", "エラー", _
MessageBoxButtons.OK, MessageBoxIcon.Error)
txtDownloadUrl.Focus()
Exit Sub
End If
If (txtSaveFilePath.Text.Length = 0) Then
MessageBox.Show("保存先を入力してください。", "エラー", _
MessageBoxButtons.OK, MessageBoxIcon.Error)
txtSaveFilePath.Focus()
Exit Sub
End If
''ファイル有無チェック
If (My.Computer.FileSystem.FileExists(txtSaveFilePath.Text) = True) Then
If MessageBox.Show("ファイルが既に存在します。上書きしますか？", "確認", _
MessageBoxButtons.OKCancel, MessageBoxIcon.Question) = _
Windows.Forms.DialogResult.Cancel Then
Exit Sub
End If
End If
''ダウンロード開始
Dim uni As New Uri(txtDownloadUrl.Text)
Try
_WebClient.DownloadFileAsync(uni, txtSaveFilePath.Text)
txtDownloadUrl.ReadOnly = True
txtSaveFilePath.ReadOnly = True
btnDownload.Enabled = False
btnCancel.Enabled = True
Catch ex As Exception
MessageBox.Show(ex.Message, "エラー", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
...
'--------------------------------------------------------------------------------
'ダウンロード進捗状況変更イベント
'--------------------------------------------------------------------------------
Private Sub _WebClient_DownloadProgressChanged(ByVal sender As Object, _
ByVal e As System.Net.DownloadProgressChangedEventArgs) _
Handles _WebClient.DownloadProgressChanged
pgbarDownload.Value = e.ProgressPercentage
lblGetBytes.Text = e.BytesReceived.ToString & " / " & e.TotalBytesToReceive.ToString
End Sub
...
'--------------------------------------------------------------------------------
'ダウンロード完了イベント
'--------------------------------------------------------------------------------
Private Sub _WebClient_DownloadFileCompleted(ByVal sender As Object, _
ByVal e As System.ComponentModel.AsyncCompletedEventArgs) _
Handles _WebClient.DownloadFileCompleted
If (e.Cancelled = True) Then
lblGetBytes.Text = "ダウンロードは中止されました"
ElseIf (e.Error Is Nothing) Then
lblGetBytes.Text = "ダウンロードが完了しました"
Else
lblGetBytes.Text = e.Error.Message
End If
pgbarDownload.Value = 0
txtDownloadUrl.ReadOnly = False
txtSaveFilePath.ReadOnly = False
btnDownload.Enabled = True
btnCancel.Enabled = False
End Sub
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