选项卡的每个项目上的更改事件触发事件 [英] selection Change event fired event on each item of tab

问题描述

我有火的标签控制变化事件，但是当被选择的选项卡中的项事件再次发射.
这是代码的一部分:>

i had fire the tab control change event but when an item of tabs is selected that event fired again.
here the some part of code:>

private void tabControl1_SelectionChanged(object sender, SelectionChangedEventArgs  e)
{
    else if (tabItem3.IsSelected)
    {
        comboBox2.Items.Clear();
        OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\shafay\Documents\project001.accdb");
        OleDbDataAdapter da = new OleDbDataAdapter("select DeptName from Department ", con);
        DataTable dt = new DataTable();
        da.Fill(dt);
        for (int i = 0; i < dt.Rows.Count; i++)
        {

            comboBox2.Items.Add(dt.Rows[i]["DeptName"]);
        }
    }
}

推荐答案

在问题给出的代码中，不清楚在何处选择TabPage.但是，通过编程方式或通过UI选择TabPage 时，将触发SelectionChanged 事件.解决方法是，可以用以下形式将公共字段声明为布尔标志:

In the code given in the question, it is not clear where the TabPage is being selected. However, when a TabPage is selected either programmatically or through the UI, the SelectionChanged event will be fired. As a work around, a public field may be declared in the form as a boolean flag say

bool skipSelectionChangedEvent = false;

现在，在tabControl1_SelectionChanged事件处理程序中，如果布尔标志为true，则跳过代码的执行.

Now, in the tabControl1_SelectionChanged event handler, skip the execution of the code if the boolean flag is true.

if (skipSelectionChangedEvent) return;

并且在选择以编程方式设置的另一个TabPage之前

And before selecting another TabPage programmatically set

skipSelectionChangedEvent = true
//Select the Tab page
//Reset the boolean flag to false to enable the SelectionChanged event
skipSelectionChangedEvent = false

希望对您有所帮助.

I hope this may be helpful.

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