<p>Tk没有任何命令来处理这个问题,Python也没有任何额外的Tk扩展来执行拖放应用程序,因此您需要一个扩展来执行这个操作。Tkdnd(位于<a href="http://sourceforge.net/projects/tkdnd">http://sourceforge.net/projects/tkdnd</a>的Tk扩展,而不是Tkdnd.py模块)对我有效。要从Python中使用它,需要一个包装器。快速搜索一个,似乎<a href="http://mail.python.org/pipermail/tkinter-discuss/2005-July/000476.html">http://mail.python.org/pipermail/tkinter-discuss/2005-July/000476.html</a>包含这样的代码。我又做了一个,因为我不喜欢另一个。我的包装器的问题是它高度未经测试,实际上我只使用了<code>bindtarget</code>函数,而且只使用了10秒左右。</p>
<p>使用下面的包装器,您可以创建一些小部件并声明它支持接收拖动的文件。下面是一个例子:</p>
<pre><code># The next two lines are not necessary if you installed TkDnd
# in a proper place.
import os
os.environ['TKDND_LIBRARY'] = DIRECTORYTOTHETKDNDBINARY
import Tkinter
from untested_tkdnd_wrapper import TkDND
root = Tkinter.Tk()
dnd = TkDND(root)
entry = Tkinter.Entry()
entry.pack()
def handle(event):
event.widget.insert(0, event.data)
dnd.bindtarget(entry, handle, 'text/uri-list')
root.mainloop()
</code></pre>
<p>这里是<code>untested_tkdnd_wrapper.py</code>的代码:</p>
<pre><code>import os
import Tkinter
def _load_tkdnd(master):
tkdndlib = os.environ.get('TKDND_LIBRARY')
if tkdndlib:
master.tk.eval('global auto_path; lappend auto_path {%s}' % tkdndlib)
master.tk.eval('package require tkdnd')
master._tkdnd_loaded = True
class TkDND(object):
def __init__(self, master):
if not getattr(master, '_tkdnd_loaded', False):
_load_tkdnd(master)
self.master = master
self.tk = master.tk
# Available pre-defined values for the 'dndtype' parameter:
# text/plain
# text/plain;charset=UTF-8
# text/uri-list
def bindtarget(self, window, callback, dndtype, event='<Drop>', priority=50):
cmd = self._prepare_tkdnd_func(callback)
return self.tk.call('dnd', 'bindtarget', window, dndtype, event,
cmd, priority)
def bindtarget_query(self, window, dndtype=None, event='<Drop>'):
return self.tk.call('dnd', 'bindtarget', window, dndtype, event)
def cleartarget(self, window):
self.tk.call('dnd', 'cleartarget', window)
def bindsource(self, window, callback, dndtype, priority=50):
cmd = self._prepare_tkdnd_func(callback)
self.tk.call('dnd', 'bindsource', window, dndtype, cmd, priority)
def bindsource_query(self, window, dndtype=None):
return self.tk.call('dnd', 'bindsource', window, dndtype)
def clearsource(self, window):
self.tk.call('dnd', 'clearsource', window)
def drag(self, window, actions=None, descriptions=None,
cursorwin=None, callback=None):
cmd = None
if cursorwin is not None:
if callback is not None:
cmd = self._prepare_tkdnd_func(callback)
self.tk.call('dnd', 'drag', window, actions, descriptions,
cursorwin, cmd)
_subst_format = ('%A', '%a', '%b', '%D', '%d', '%m', '%T',
'%W', '%X', '%Y', '%x', '%y')
_subst_format_str = " ".join(_subst_format)
def _prepare_tkdnd_func(self, callback):
funcid = self.master.register(callback, self._dndsubstitute)
cmd = ('%s %s' % (funcid, self._subst_format_str))
return cmd
def _dndsubstitute(self, *args):
if len(args) != len(self._subst_format):
return args
def try_int(x):
x = str(x)
try:
return int(x)
except ValueError:
return x
A, a, b, D, d, m, T, W, X, Y, x, y = args
event = Tkinter.Event()
event.action = A # Current action of the drag and drop operation.
event.action_list = a # Action list supported by the drag source.
event.mouse_button = b # Mouse button pressed during the drag and drop.
event.data = D # The data that has been dropped.
event.descr = d # The list of descriptions.
event.modifier = m # The list of modifier keyboard keys pressed.
event.dndtype = T
event.widget = self.master.nametowidget(W)
event.x_root = X # Mouse pointer x coord, relative to the root win.
event.y_root = Y
event.x = x # Mouse pointer x coord, relative to the widget.
event.y = y
event.action_list = str(event.action_list).split()
for name in ('mouse_button', 'x', 'y', 'x_root', 'y_root'):
setattr(event, name, try_int(getattr(event, name)))
return (event, )
</code></pre>
<p>与Tkdnd一起,您将发现一个<code>tkdnd.tcl</code>程序,它比它提供的C扩展更高一级。我没有包装这个高级代码,但是用Python复制它可能比使用这个低级包装器更有趣。</p>