Question

我有一个包含两个组合框（cmbSection，cmbGrade）和两个文本框（txtName，txtSectionSize）的表单我想从combobox和txtSectionSize获取文本并将其放在txtName中，这样我的代码就像这样锁定

 public partial class FRM_Item : Form
 {
    //public string State = "Add";
    BL.CLS_Item prd = new BL.CLS_Item();

    public FRM_Item()
    {
        InitializeComponent();

        cmbSection.DataSource = prd.Get_All_Items();
        cmbSection.DisplayMember = "Name_SectionType";
        cmbSection.ValueMember = "ID_SectionType";

        cmbGrade.DataSource = prd.Get_All_Grade();
        cmbGrade.DisplayMember = "Name_Grade";
        cmbGrade.ValueMember = "ID_Grade";
    }
private void cmbSection_SelectedIndexChanged(object sender, EventArgs e)
    {
        this.txtName.Text = cmbSection.Text + txtSectionSize.Text + "-" + cmbGrade.Text;
    }

    private void cmbGrade_SelectedIndexChanged(object sender, EventArgs e)
    {
        this.txtName.Text = cmbSection.Text + txtSectionSize.Text + "-" + cmbGrade.Text;

    }

    private void txtSectionSize_TextChanged(object sender, EventArgs e)
    {
        this.txtName.Text = cmbSection.Text + txtSectionSize.Text + "-" + cmbGrade.Text;
    }

当我打开表单时，我在txtName中获取System.Data.DataRowView但是当我从combobox中获取任何文本时，我在文本框中获得正确的值我通过将此代码移动到表单来解决此问题

        private void FRM_Item_Load(object sender, EventArgs e)
    {
        cmbSection.DataSource = prd.Get_All_Items();
        cmbSection.DisplayMember = "Name_SectionType";
        cmbSection.ValueMember = "ID_SectionType";

        cmbGrade.DataSource = prd.Get_All_Grade();
        cmbGrade.DisplayMember = "Name_Grade";
        cmbGrade.ValueMember = "ID_Grade";
    }

当我从另一种形式的按钮打开此表单时，我现在遇到的问题组合框始终是第一个值，而不是来自datagrid的值

private void btnEdit_Click(object sender, EventArgs e)
    {
        FRM_Item frm = new FRM_Item();
        frm.txtName.Text = this.dataGridView1.CurrentRow.Cells[1].Value.ToString();
        frm.cmbSection.Text = this.dataGridView1.CurrentRow.Cells[2].Value.ToString();
        frm.txtSectionSize.Text = this.dataGridView1.CurrentRow.Cells[3].Value.ToString();
        frm.cmbGrade.Text = this.dataGridView1.CurrentRow.Cells[4].Value.ToString();

        frm.ShowDialog();
    }

我如何解决这个问题

Answer 1

在分配组合框之前填充组合框。现在，它向后。

我建议将此代码移动到子窗体构造函数，或者在尝试在父窗体中分配属性之前调用可以调用的方法。

    cmbSection.DataSource = prd.Get_All_Items();
    cmbSection.DisplayMember = "Name_SectionType";
    cmbSection.ValueMember = "ID_SectionType";

    cmbGrade.DataSource = prd.Get_All_Grade();
    cmbGrade.DisplayMember = "Name_Grade";
    cmbGrade.ValueMember = "ID_Grade";

对于事件，如果你把代码放在构造函数中，你可以有一个boolean属性，如果你没有完成构造函数，或者没有在设计器中有事件，那么就不能运行事件代码在你填充组合框后的构造函数中。

当我从另一个表单打开它而不是datagrid的值时，组合框始终显示第一个值

1 个答案: