如何在按钮单击时保存数据库中项目模板的下拉列表选择值？

Question

请找到图片。这是我的整个代码，我想在保存按钮单击时保存每一行。我能够从单元格0和单元格1获取值，但无法从单元格2中获取值，其中我有下拉列表选择的值。我得到默认值＆＃34;忽略＆＃34;而不是选定的项目。那么如何获得下拉列表的选定值？

private int currentImage = 0;
int[] images = { R.drawable.a1, R.drawable.b1, R.drawable.c1, R.drawable.d1, R.drawable.e1, R.drawable.f1 };
private int currentImage2 = 0;
int[] images2 = { R.drawable.a2, R.drawable.b2, R.drawable.c2, R.drawable.d2, R.drawable.e2, R.drawable.f2 };
private int currentImage3 = 0;
int[] images3 = { R.drawable.a3, R.drawable.b3, R.drawable.c3, R.drawable.d3, R.drawable.e3, R.drawable.f3 };
private int[] sounds = { R.raw.sound1, R.raw.sound2, R.raw.sound3, R.raw.sound4, R.raw.sound5, R.raw.sound6,  };
private int mysound = 0;
private int[] sounds2 = { R.raw.sound1a, R.raw.sound2a, R.raw.sound3a,R.raw.sound4a, R.raw.sound5a, R.raw.sound6a,  };
private int mysound2 = 0;
MediaPlayer mp;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_aplhascreen);

    MainImage = (ImageButton) findViewById(R.id.imageButton1);
    ImageLeft = (ImageButton) findViewById(R.id.imageButton2);
    ImageRight = (ImageButton) findViewById(R.id.imageButton3);
    nextButton = (ImageButton) findViewById(R.id.imageButton5);

    ImageLeft.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            mp = MediaPlayer.create(Alphascreen.this, sounds[0]);
            mp.start();
            mysound++;

            ImageRight.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                mp = MediaPlayer.create(Alphascreen.this, sounds2[0]);
                    mp.start();
                    mysound2++;

                }

            });

            nextButton.setOnClickListener(aButtonChangeImageListener);

        }

        View.OnClickListener aButtonChangeImageListener = new View.OnClickListener() {

            public void onClick(View v) {
                currentImage++;
                currentImage = currentImage % images.length;
                currentImage2++;
                currentImage2 = currentImage2 % images.length;
                currentImage3++;
                currentImage3 = currentImage3 % images.length;
               mysound++;
                mysound = mysound % sounds.length;
               mysound2++;
               mysound2 = mysound2 % sounds2.length;

                MainImage.setImageResource(images[currentImage]);
                ImageLeft.setImageResource(images2[currentImage2]);
                ImageRight.setImageResource(images3[currentImage3]);

            }
        };
    });
}}

<div>
    <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns = "False" 
           OnRowDataBound = "OnRowDataBound" Width="544px">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField HeaderText="Name" DataField="Name" />       
        <asp:TemplateField HeaderText = "Mapping" >
        <ItemTemplate>
            <asp:DropDownList ID="DropDownList1" runat="server" style="font-size: medium; font-family: Cambria" Width="300px">
            </asp:DropDownList>
        </ItemTemplate>
    </asp:TemplateField>
    </Columns>
    </asp:GridView>
    <br />
    <asp:Button ID="Button2" runat="server" Text="Save" 
           style="font-size: medium; font-family: Cambria" BorderStyle="Groove" 
           height="32px"  Width="116px" onclick="Save_Click" />
    </div>





 private void BindGrid()
{
    DataTable dt = new DataTable();
    connection();
    cmd = new SqlCommand("Select top 0 * from  F3_BC_Product_Mapping_Data", con);
    con.Open();
    adapter = new SqlDataAdapter(cmd);
    ds = new DataSet();        
    adapter.Fill(ds, "mytable");
    int j = 1;
    dt.Columns.AddRange(new DataColumn[2] { new DataColumn("Id", typeof(int)), new DataColumn("Name", typeof(string)) });
    foreach (DataColumn column in ds.Tables[0].Columns)
    {
        dt.Rows.Add(j,column.ColumnName);
        j++;
    } 
    GridView2.DataSource = dt;
    GridView2.DataBind();
    con.Close();

}

  protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        DropDownList ddlMap = (e.Row.FindControl("DropDownList1") as DropDownList);
        DataTable dt = new DataTable();
        dt = (DataTable)Session["data"];
        for (int i = 0; i < dt.Columns.Count; i++)
        {
            ddlMap.Items.Add(dt.Columns[i].Caption.ToString());
        }
        ddlMap.Items.Insert(0, new ListItem("Ignore"));
    }
}

Answer 1

如果您获得默认值，则必须查看绑定代码。我认为您在绑定之前没有使用if(!Page.IsPostBack)并在下拉列表中设置默认值。尝试更改OnRowDataBound，如下所示。

protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow && !Page.IsPostBack)
    {
        DropDownList ddlMap = (e.Row.FindControl("DropDownList1") as DropDownList);
        DataTable dt = new DataTable();
        dt = (DataTable)Session["data"];
        for (int i = 0; i < dt.Columns.Count; i++)
        {
            ddlMap.Items.Add(dt.Columns[i].Caption.ToString());
        }
        ddlMap.Items.Insert(0, new ListItem("Ignore"));
    }
}