Question

我创建了一个custimazibale提示

public static class Prompt
{
    public static string ShowDialog(int columnnumber, string columnname)
    {
        Form prompt = new Form();
        prompt.Width = 500;
        prompt.Height = 150;
        prompt.FormBorderStyle = FormBorderStyle.FixedDialog;
        prompt.Text = columnname;
        prompt.StartPosition = FormStartPosition.CenterScreen;
        Label textLabel = new Label() { Left = 50, Top = 20 };
        ComboBox comboBox = new ComboBox() { Left = 50, Top = 50, Width = 400 };
        comboBox.Items.AddRange(new string[] { "a","b","c" });
        comboBox.DropDownStyle = ComboBoxStyle.DropDownList;
        comboBox.SelectedItem = columnname;
        Button confirmation = new Button() { Text = "Ok", Left = 350, Width = 100, Top = 80 };
        confirmation.Click += (sender, e) => { prompt.Close(); };
        textLabel.Text = "Colonne " + (columnnumber + 1).ToString() + " : " + columnname;
        prompt.Controls.Add(comboBox);
        prompt.Controls.Add(confirmation);
        prompt.Controls.Add(textLabel);
        prompt.AcceptButton = confirmation;
        prompt.ShowDialog();
        prompt.AcceptButton = confirmation;

        return comboBox.Text;
    }
}

然后我在点击标题时以我的主窗体调用它

private void dataGridView1_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
     dt.Columns[e.ColumnIndex].ColumnName = Prompt.ShowDialog(e.ColumnIndex, dataGridView1.Columns[e.ColumnIndex].Name);
}

即使单击按钮关闭，问题仍然是我的文本更改。但是我希望它只在用户点击按钮＆＃34; OK＆＃34;。

时才能改变

Answer 1

如果不是null，您可以评估DialogResult并返回OK：

public static class Prompt
{
    public static string ShowDialog(int columnnumber, string columnname)
    {
        using (Form prompt = new Form())
        {
            // other code
            return prompt.DialogResult == DialogResult.OK ? comboBox.Text : null;
        }
    }
}

然后用你的另一种方法：

private void dataGridView1_ColumnHeaderMouseClick(object sender, EventArgs e)
{
    var result = Prompt.ShowDialog(e.ColumnIndex, 
                                   dataGridView1.Columns[e.ColumnIndex].Name);
    if (result != null)
        dt.Columns[e.ColumnIndex].ColumnName = result;
}

在prompt内，你应该相应地设置DialogResult：

confirmation.Click += (sender, e) =>
    {
        prompt.DialogResult = DialogResult.OK;
        prompt.Close();
    };

提示：除了result != null，您还可以使用!String.IsNullOrWhiteSpace(result)仅在输入内容时更新列名。

Answer 2

我会选择这样的事情：

using(Form prompt = new Form())
{
    //Initialize the components of your form

    DialogResult result = prompt.ShowDialog();
    if(result == DialogResult.OK)
    {
       //return whatever it is you want to return
    }
}

在表单中，您可以通过prompt.DialogResult = DialogResult.OK设置DialogResult以及更多选项（DialogResult.Cancel，DialogResult.Retry等）。

Answer 3

你可以在确认时设置一个bool，如果没有确认则使用它返回null，如下所示：

public static string ShowDialog(int columnnumber, string columnname)
{
    Form prompt = new Form();
    prompt.Width = 500;
    prompt.Height = 150;
    prompt.FormBorderStyle = FormBorderStyle.FixedDialog;
    prompt.Text = columnname;
    prompt.StartPosition = FormStartPosition.CenterScreen;
    Label textLabel = new Label()
    {
        Left = 50,
        Top = 20
    };
    ComboBox comboBox = new ComboBox()
    {
        Left = 50,
        Top = 50,
        Width = 400
    };
    comboBox.Items.AddRange(new string[] { "a", "b", "c" });
    comboBox.DropDownStyle = ComboBoxStyle.DropDownList;
    comboBox.SelectedItem = columnname;
    Button confirmation = new Button()
    {
        Text = "Ok",
        Left = 350,
        Width = 100,
        Top = 80
    };

    bool confirmed = false;

    confirmation.Click += (sender, e) =>
    {
        prompt.Close();
        confirmed = true;
    };
    textLabel.Text = "Colonne " + (columnnumber + 1).ToString() + " : " + columnname;
    prompt.Controls.Add(comboBox);
    prompt.Controls.Add(confirmation);
    prompt.Controls.Add(textLabel);
    prompt.AcceptButton = confirmation;
    prompt.ShowDialog();
    prompt.AcceptButton = confirmation;

    return confirmed ? comboBox.Text : null;
}

您的调用代码需要检查null的返回值，并且只有在返回的值不为null时才执行某些操作。

如何在单击“确定”时返回值

3 个答案: