c#打开txt文件并导入到textbox中

OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Title = " 请选择您要导入的模板文件：";
            openFileDialog.Filter = "TextDocument(*.txt)|*.txt|TextDocument(*.ini)|*.ini";
            openFileDialog.ShowDialog();
            if (openFileDialog.FileName != "")//判断文件名是否为空
            {
                StreamReader streamReader = new StreamReader(openFileDialog.FileName, Encoding.Default);
                this.txtextBox.Text = streamReader.ReadToEnd();
            }