继续打开OpenFileDialog,直到选择有效文件

Question

我有打开OpenFileDialog的代码,我正在检查文件的大小以确保它不超过特定限制.但是,如果用户选择了一个大尺寸文件,我需要警告他并引导他返回对话框以选择其他文件或单击取消.

这就是我尝试过的:

        OpenFileDialog dialog = new OpenFileDialog();
        dialog.Filter = "Jpeg files, PDF files, Word files|*.jpg;*.pdf;*.doc;*.docx";
        while (dialog.ShowDialog() != DialogResult.Cancel)
        {
                var size = new FileInfo(dialog.FileName).Length;
                if (size > 250000)
                {
                    MessageBox.Show("File size exceeded");
                    continue;
                }
        }

编辑:我也尝试了以下代码,但每次调用ShowDialog时它都会打开对话框.因此,如果用户选择的文件大小为限制的3倍,则对话框将出现3次.

  OpenFileDialog dialog = new OpenFileDialog();
        dialog.Filter = "Jpeg files, PDF files, Word files|*.jpg;*.pdf;*.doc;*.docx";
        dialog.FileOk += delegate(object s, CancelEventArgs ev)
        {
            var size = new FileInfo(dialog.FileName).Length;
            if (size > 250000)
            {
                XtraMessageBox.Show("File size");
                dialog.ShowDialog();
            }
        };
        if (dialog.ShowDialog() == DialogResult.OK)
        {
            XtraMessageBox.Show("File Selected");
        }

Answer 1

你在中途,FileOk事件就是你想要使用的.您缺少的是将e.Cancel属性设置为true.这使对话框保持打开状态,避免您不得不一遍又一遍地显示它.像这样:

        OpenFileDialog dialog = new OpenFileDialog();
        dialog.Filter = "Jpeg files, PDF files, Word files|*.jpg;*.pdf;*.doc;*.docx";
        dialog.FileOk += delegate(object s, CancelEventArgs ev) {
            var size = new FileInfo(dialog.FileName).Length;
            if (size > 250000) {
                MessageBox.Show("Sorry, file is too large");
                ev.Cancel = true;             // <== here
            }
        };
        if (dialog.ShowDialog() == DialogResult.OK) {
            MessageBox.Show(dialog.FileName + " selected");
        }