将数据从 DataGridView 中的列传递到另一种形式的组合框

Question

我希望 DataGridView 中第 2 列（所有行）的数据作为另一种形式的组合框的输入。我试过的下面的代码包含 2 个错误 comboBox1 在当前上下文中不存在 并且 非静态字段需要对象引用 。下面是我的代码。

表单 1（带有 DataGridView 和按钮）

// put as public string as the DataGridView rows will keep updating
public string data;
public Form1()
{
    InitializeComponent();
}

//button to go Form 2 which contains the combobox
private void Button1_Click(object sender, EventArgs e) 
{
    string data = string.Empty;
    int indexOfYourColumn = 2;

    foreach (DataGridViewRow row in dataGridView1.Rows)
    data = row.Cells[indexOfYourColumn].Value.ToString();

    comboBox1.Items.Add(data);

    this.Hide();
    FormsCollection.Form2.Show();
}

Form2（带组合框）

//put as public to obtain value from Form 1
public string data; 
public Form 2()
{
    InitializeComponent();
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    comboBox1.Text = Form1.data;

    //not to repeat the value entered if a particular value has been entered
    String s = data;
    if (!comboBox1.Items.Contains(s))
    {
        comboBox1.Items.Add(s);
    }
}

Answer 1

首先为表格 2 定义 public 参数

public String data;

然后在打开 Form 2 时在 Form 1 中设置数据值，如下所示：

Form2 form2 = new Form2();
form2.data = your_form1_data;
form2.Show();

现在您在 Form2 中有了数据值。

Answer 2

当您想要传递一组信息时，您需要使用适当的类型。例如 List<string> 不是简单的字符串。然后你创建或获取第二种形式的实例，只有在你拥有第二种形式的实例之后，你才能给它提供要显示的数据集合

private void Button1_Click(object sender, EventArgs e) 
{
    // These is where you store the elements to pass to the Form2 instance
    List<string> data = new List<string>();;

    int indexOfYourColumn = 2;

    // Build the collection from the selected column for each row
    foreach (DataGridViewRow row in dataGridView1.Rows)
        data.Add(row.Cells[indexOfYourColumn].Value.ToString());

    this.Hide();

    // pass your data to the public property of the Form2 instance
    Form2 f = FormsCollection.Form2;
    f.Data = data;
    f.Show();

}

如您所见，data 值通过 public 属性传递给第二个实例，并且在 [=20] 的集合访问器中=] 你改变了内部combobox1的内容

private List<string> _data;
public List<string> Data 
{
    get { return _data; }
    set 
    {
        _data = value;

        // This code uses the DataSource property of the combobox
        // combobox1.DataSource = null;
        // combobox1.DataSource = value;

        // This code works directly with the Items collection of the combo
        combobox1.Items.Clear();
        foreach(string s in _data)
            combobox1.Items.Add(s);
    }
}; 

public Form 2()
{
    InitializeComponent();
}
...

将数据从 DataGridView 中的列传递到另一种形式的组合框

Passing data from a column in a DataGridView to a combobox in another form

c#

combobox

datagridviewcolumn