Winform ComboBox 绑定数据源 触发SelectedIndexChanged事件 处理办法

Posted 2020-11-27 superfeeling

最近寫Winform程式,發現Winform中的ComboBox和Web中的Dropdown相差很大,在ComboBox 绑定数据源 會触发SelectedIndexChanged事件,很困擾,查找了資料,處理方法大體分為三種

1.添加一个标记位，在绑定前设置为false，绑定完成后设置回true(個人覺得用起來的很奇怪)

void BindComboBox()
{
flag=false;
ComboxBox1.ValueMember="ValueColumn";
ComboxBox1.DisplayMember="DisplayColumn";
ComboxBox1.DataSource=DataTable1;
flag=true;
}

privatevoid ComboxBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if(flag)
{
//Do something
}
}

2.绑定前，将SelectedIndexChanged的委托去掉，等绑定完成后，再添加事件委托(覺得比較複雜)

void BindComboBox()
{ //去除委托
ComboBox1.SelectedIndexChanged -= new EventHandler(ComboBox1_SelectedIndexChanged);
ComboBox1.DataSource = null;
ComboBox1.ValueMember = "ValueColumn";
ComboBox1.DataSource = DataTable1;
//添加委托
ComboBox1.SelectedIndexChanged += new EventHandler(ComboBox1_SelectedIndexChanged);
ComboBox1.DisplayMember = "DisplayColumn";
}

3.判斷是否是選擇狀態(最後本人用的)

privatevoid ComboxBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if(ComboxBox1.ContainsFocus)
{
//Do something
}
}