拖放操作是一个我比较喜欢的用户体验,但实现起来稍显麻烦,这里我将它的常用方式简单的集合了一下,作为扩展方法,以便快速调用:
static
class
DrapDropExtend
{
public
static
void SimpleDrapDrop<T>(this
Control c, string dataformat, Action<T> hanlder) where T : class
{
c.AllowDrop = true;
c.DragEnter += (s, e) =>
{
if (e.Data.GetDataPresent(dataformat))
e.Effect = DragDropEffects.Copy;
else
e.Effect = DragDropEffects.None;
};
c.DragDrop += (s, e) =>
{
var data = e.Data.GetData(dataformat) as T;
hanlder(data);
};
}
public
static
void SimpleDrapDrop(this
Control c, Action<DragEventArgs> enterHanlder, Action<DragEventArgs> dropHanlder)
{
c.AllowDrop = true;
c.DragEnter += (s, e) => enterHanlder(e);
c.DragDrop += (s, e) => enterHanlder(e);
}
public
static
void SimpleDrapDrop(this
Control c, DragEventHandler enterHanlder, DragEventHandler dropHanlder)
{
c.AllowDrop = true;
c.DragEnter += enterHanlder;
c.DragDrop += dropHanlder;
}
}
该类使得实现拖放更加简单了,一个简单的示例如下:
public Form1()
{
InitializeComponent();
this.SimpleDrapDrop<string>(DataFormats.Text, x => this.Text = x);
}
这比通过IDE来实现要简洁得多。