Question

我的应用有一个ViewController，包含多个文本字段和自定义UI元素，排列为带有“提交”和“重置”按钮的表单。

我想在用户点击提交按钮时重置所有文本字段和自定义UI元素，以便用户感觉再次打开相同的表单。

我尝试在点击“提交”按钮时调用ViewDidLoad（）和setNeedsDisplay（），但之前由用户填充的数据保持不变。

请帮助！

Answer 1

只需将所有文本字段的文本设置为空字符串（text值）即可。没有神奇的功能来清理视图中的所有内容。

唯一的另一个解决方案是再次实际显示ViewController，但这可能不是你想要的，因为它会导致开销，你可能会在屏幕上看到一些切换。

Answer 2

如果您以编程方式对文本字段和其他对象进行编码，则可以通过在预定义方法中添加所有UI代码来每次刷新viewController： - （void）viewWillAppear：（BOOL）animated {}并且您应该删除所有自我.view元素通过添加此代码。 [self.view.subviews makeObjectsPerformSelector：@selector（removeFromSuperview）];

viewWillAppear中的代码将如下所示。

Traceback (most recent call last):
  File "/Users/root/test/foo.py", line 2, in <module>
    import socketio
  File "/Users/root/test/venv/lib/python3.6/site-packages/socketio/__init__.py", line 8, in <module>
    from .zmq_manager import ZmqManager
  File "/Users/root/test/venv/lib/python3.6/site-packages/socketio/zmq_manager.py", line 5, in <module>
    import eventlet.green.zmq as zmq
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/__init__.py", line 10, in <module>
    from eventlet import convenience
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/convenience.py", line 6, in <module>
    from eventlet.green import socket
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/green/socket.py", line 21, in <module>
    from eventlet.support import greendns
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/support/greendns.py", line 390, in <module>
    resolver = ResolverProxy(hosts_resolver=HostsResolver())
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/support/greendns.py", line 171, in __init__
    self._load()
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/support/greendns.py", line 198, in _load
    lines = self._readlines()
  File "/Users/root/test/venv/lib/python3.6/site-packages/eventlet/support/greendns.py", line 184, in _readlines
    for line in fp:
  File "/Users/root/test/venv/bin/../lib/python3.6/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe9 in position 33: ordinal not in range(128)

如何在iOS中按下按钮重置ViewController

2 个答案: