python将资源管理器文件拖放到tkinter entry widg

Question

我对Python还不太熟悉。我正在尝试向TKinter条目小部件输入一个文件名（完整路径）。 由于文件名的路径可能很长，我希望能够直接拖放文件 从Windows资源管理器。在Perl中，我看到了以下内容：

use Tk::DropSite;
.
.
my $mw = new MainWindow;
$top = $mw->Toplevel;
$label_entry = $top->Entry(-width => '45',. -background => 'ivory2')->pack();
$label_entry->DropSite(-dropcommand => \&drop,-droptypes => 'Win32',);

在Python中使用TKinter有类似的功能吗？

Answer 1

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http://sourceforge.net/projects/tkdnd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http://mail.python.org/pipermail/tkinter-discuss/2005-July/000476.html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bindtarget函数，而且只使用了10秒左右。

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：

# 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()

这里是untested_tkdnd_wrapper.py的代码：

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, )

与Tkdnd一起，您将发现一个tkdnd.tcl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。