c# - DataGridViewComboBoxCell 已填充但不会显示内容
问题描述
我正在尝试为我设置为 ComboBoxcolumn 的 datagridview 列之一动态设置自定义下拉列表。当我运行我的应用程序时,我看到我的单元格中有值。但是,我看到 UI 中没有弹出任何值。
private void CustomComboBoxColumns(string filter)
{
DataGridViewComboBoxColumn ComboBoxColumn = new DataGridViewComboBoxColumn();
DataTable dt;
ComboBoxColumn.HeaderText = "category";
ComboBoxColumn.DataPropertyName = "category";
ComboBoxColumn.ReadOnly = false;
ComboBoxColumn.MaxDropDownItems = 100;
ComboBoxColumn.AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells;
ComboBoxColumn.FlatStyle = FlatStyle.Flat;
ComboBoxColumn.ValueMember = "category";
ComboBoxColumn.DisplayMember = "category";
_iprDataGridView.Columns.Insert(16, ComboBoxColumn);
for (int i = 0; i < _iprDataGridView.Rows.Count; i++)
{
dt = GetDataForCategory(filter);
((DataGridViewComboBoxCell)_iprDataGridView.Rows[i].Cells[16]).DataSource = dt;
}
}
private DataTable GetDataForCategory(string filter)
{
DbConnection db = new DbConnection();
string connString = db.BuildConnectionString();
DataTable dt = new DataTable();
DataSet ds = new DataSet();
string query = "Select category from cd_category where category like '%" + filter + "%' order by category";
using (SqlConnection conn = new SqlConnection(connString))
{
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
SqlDataAdapter da = new SqlDataAdapter(query, conn);
da.Fill(ds, "category");
dt = ds.Tables["category"];
da.Dispose();
conn.Close();
}
return dt;
}
当我附加调试器并检查 ((DataGridViewComboBoxCell)_iprDataGridView.Rows[i].Cells[16]).DataSource = dt; 我的项目集合中有一些值,它只是不会显示它。
这是有关如何设置 datagridview 的更多代码。
_iprDataGridView.DataSource = _dbHelper.Select(queryBuild.ToString(), parameters, dbConnection);
if (_iprDataGridView.DataSource == null) return;
// In order to display and match the PIR table values, that are requried to be in
// a comboBox menu, we need to remove the columns that have been populated and then
// re-add them as comboBoxs
ConfigureDataGridView();
ConfigureComboBoxColumns();
ConfigureTextBoxColumns();
我在想在 ConfigureTextBoxColumns() 之后我将创建我的方法,该方法将遍历 datagridview 并创建一个新的类别 comboboxcolumn 并根据另一个列的值插入一个新的 comboboxcell。
这是如何为 datagridview 生成列的代码
private void ConfigureComboBoxColumns()
{
DataGridViewHelper dataGridViewHelper = new DataGridViewHelper();
// Columns being converted to comboboxcolumns must be removed, created, and re-inserted
dataGridViewHelper.RemoveColumns(ref _iprDataGridView,
Columns.severity.ToString(),
Columns.phase.ToString(),
Columns.app.ToString(),
Columns.project.ToString(),
Columns.acceptancePeriod.ToString(),
Columns.classConfirmed.ToString(),
Columns.oncall.ToString(),
Columns.warranty.ToString(),
Columns.release.ToString(),
Columns.category.ToString(),
Columns.ticketType.ToString());
DataGridViewComboBoxColumn comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.severity.ToString());
comboBoxColumn.ValueType = typeof(int);
string query = IPRDetailsConstants.SELECT_SEVERITY + IPRDetailsConstants.SEVERITY_COL;
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.severity.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.severity, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.phase.ToString());
query = IPRDetailsConstants.SELECT_PHASE + IPRDetailsConstants.PHASE_COL;
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.phase.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.phase, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.app.ToString());
query = IPRDetailsConstants.SELECT_APP + IPRDetailsConstants.APP_COL;
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.app.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.app, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.project.ToString());
bool activeProjectsOnly = bool.Parse(ConfigurationManager.AppSettings.Get("ActiveProjectsOnly"));
query = IPRDetailsConstants.SELECT_PROJECT + (activeProjectsOnly ? IPRDetailsConstants.PROJECT_COL_ACTIVE : IPRDetailsConstants.PROJECT_COL);
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.project.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.project, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.acceptancePeriod.ToString());
comboBoxColumn.HeaderText = Resources.IprDetails_ConfigureComboBoxColumns_ap;
comboBoxColumn.HeaderCell.ToolTipText = "acceptancePeriod";
dataGridViewHelper.SetComboBoxChoicesStatic(ref comboBoxColumn, Columns.acceptancePeriod.ToString(), Resources.Y, Resources.N, Resources.S, Resources.X);
_iprDataGridView.Columns.Insert((int)Columns.acceptancePeriod, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.classConfirmed.ToString());
comboBoxColumn.HeaderText = Resources.IprDetails_ConfigureComboBoxColumns_cc;
comboBoxColumn.HeaderCell.ToolTipText = "classConfirmed";
dataGridViewHelper.SetComboBoxChoicesStatic(ref comboBoxColumn, Columns.classConfirmed.ToString(), Resources.Y, Resources.N, Resources.X);
_iprDataGridView.Columns.Insert((int)Columns.classConfirmed, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.oncall.ToString());
comboBoxColumn.HeaderText = Resources.IprDetails_ConfigureComboBoxColumns_oc;
comboBoxColumn.HeaderCell.ToolTipText = "onCall";
dataGridViewHelper.SetComboBoxChoicesStatic(ref comboBoxColumn, Columns.oncall.ToString(), Resources.Y, Resources.N, Resources.X);
_iprDataGridView.Columns.Insert((int)Columns.oncall, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.warranty.ToString());
comboBoxColumn.HeaderText = Resources.IprDetails_ConfigureComboBoxColumns_w;
comboBoxColumn.HeaderCell.ToolTipText = "warranty";
dataGridViewHelper.SetComboBoxChoicesStatic(ref comboBoxColumn, Columns.warranty.ToString(), Resources.Y, Resources.N, Resources.X);
_iprDataGridView.Columns.Insert((int)Columns.warranty, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.ticketType.ToString());
comboBoxColumn.HeaderText = Resources.IprDetails_ConfigureComboBoxColumns_tt;
comboBoxColumn.HeaderCell.ToolTipText = "ticketType";
dataGridViewHelper.SetComboBoxChoicesStatic(ref comboBoxColumn, Columns.ticketType.ToString(), "I", "P", "R", "K", "Q");
_iprDataGridView.Columns.Insert((int)Columns.ticketType, comboBoxColumn);
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.release.ToString());
bool activeReleasesOnly = bool.Parse(ConfigurationManager.AppSettings.Get("ActiveReleasesOnly"));
query = IPRDetailsConstants.SELECT_RELEASE + (activeReleasesOnly ? IPRDetailsConstants.RELEASE_COL_ACTIVE : IPRDetailsConstants.RELEASE_COL);
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.release.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.release, comboBoxColumn);
/*
comboBoxColumn = dataGridViewHelper.CreateComboBoxColumn(Columns.category.ToString());
query = IPRDetailsConstants.SELECT_CATEGORY + IPRDetailsConstants.CATEGORY_COL;
dataGridViewHelper.SetComboBoxChoicesDataSource(ref comboBoxColumn, Columns.category.ToString(), query, dbConnection);
_iprDataGridView.Columns.Insert((int)Columns.category, comboBoxColumn);
*/
}
我注释掉了他们的专栏,以便插入我自己的类别。我正在更新这个不是我开发的应用程序。
解决方案
看起来您正在尝试将数据绑定到控件。设置源后,您必须绑定它。请参阅我所做的编辑。此链接提供更多信息和示例 https://support.microsoft.com/en-us/help/307860/asp-net-data-binding-overview
private void CustomComboBoxColumns(string filter)
{
DataGridViewComboBoxColumn ComboBoxColumn = new DataGridViewComboBoxColumn();
DataTable dt;
ComboBoxColumn.HeaderText = "category";
ComboBoxColumn.DataPropertyName = "category";
ComboBoxColumn.ReadOnly = false;
ComboBoxColumn.MaxDropDownItems = 100;
ComboBoxColumn.AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells;
ComboBoxColumn.FlatStyle = FlatStyle.Flat;
ComboBoxColumn.ValueMember = "category";
ComboBoxColumn.DisplayMember = "category";
_iprDataGridView.Columns.Insert(16, ComboBoxColumn);
for (int i = 0; i < _iprDataGridView.Rows.Count; i++)
{
dt = GetDataForCategory(filter);
((DataGridViewComboBoxCell)_iprDataGridView.Rows[i].Cells[16]).DataSource = dt;
((DataGridViewComboBoxCell)_iprDataGridView.Rows[i].Cells[16]).DataBind(); //this edit
}
}
我还强烈建议学习使用参数化查询来防止 sql 注入
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