OpenFileDialog.OpenFile 方法
定义
重要
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打开用户选定的具有只读权限的文件。 该文件由 FileName 属性指定。
public:
System::IO::Stream ^ OpenFile();
public System.IO.Stream OpenFile ();
member this.OpenFile : unit -> System.IO.Stream
Public Function OpenFile () As Stream
返回
指定用户所选定的只读文件的 Stream。
例外
文件名为 null
。
示例
下面的代码示例演示如何使用 OpenFile 方法。
private:
void button1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
Stream^ myStream;
OpenFileDialog^ openFileDialog1 = gcnew OpenFileDialog;
openFileDialog1->InitialDirectory = "c:\\";
openFileDialog1->Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
openFileDialog1->FilterIndex = 2;
openFileDialog1->RestoreDirectory = true;
if ( openFileDialog1->ShowDialog() == System::Windows::Forms::DialogResult::OK )
{
if ( (myStream = openFileDialog1->OpenFile()) != nullptr )
{
// Insert code to read the stream here.
myStream->Close();
}
}
}
var fileContent = string.Empty;
var filePath = string.Empty;
using (OpenFileDialog openFileDialog = new OpenFileDialog())
{
openFileDialog.InitialDirectory = "c:\\";
openFileDialog.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
openFileDialog.FilterIndex = 2;
openFileDialog.RestoreDirectory = true;
if (openFileDialog.ShowDialog() == DialogResult.OK)
{
//Get the path of specified file
filePath = openFileDialog.FileName;
//Read the contents of the file into a stream
var fileStream = openFileDialog.OpenFile();
using (StreamReader reader = new StreamReader(fileStream))
{
fileContent = reader.ReadToEnd();
}
}
}
MessageBox.Show(fileContent, "File Content at path: " + filePath, MessageBoxButtons.OK);
Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim myStream As Stream = Nothing
Dim openFileDialog1 As New OpenFileDialog()
openFileDialog1.InitialDirectory = "c:\"
openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
openFileDialog1.FilterIndex = 2
openFileDialog1.RestoreDirectory = True
If openFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
Try
myStream = openFileDialog1.OpenFile()
If (myStream IsNot Nothing) Then
' Insert code to read the stream here.
End If
Catch Ex As Exception
MessageBox.Show("Cannot read file from disk. Original error: " & Ex.Message)
Finally
' Check this again, since we need to make sure we didn't throw an exception on open.
If (myStream IsNot Nothing) Then
myStream.Close()
End If
End Try
End If
End Sub
注解
该方法 OpenFile 用于提供一个工具,用于快速从对话框中打开文件。 该文件以只读模式打开,以实现安全目的。 若要以读/写模式打开文件,必须使用其他方法,例如 FileStream。