我有一个文本字段,并将其绑定(bind)到一个 NSString
实例变量。
当我在文本字段中键入内容时,它不会更新变量。它会等到我按下 Enter 键。我不想每次都按 Enter 键。
我需要更改什么才能立即更改绑定(bind)值?
最佳答案
默认情况下,NSTextField
的值绑定(bind)不会持续更新。要解决此问题,您需要在选择文本字段后,选中“值”标题下的“绑定(bind)检查器”中的“连续更新值”框:
但是,大多数情况下,您真正想要做的是当用户完成编辑并按下按钮(“保存”或“确定”)时更新文本字段绑定(bind)的属性, 例如)。为此,您无需如上所述不断更新属性,只需结束编辑即可。 Daniel Jalkut provides an extremely useful implementation of just such a method :
@interface NSWindow (Editing)
- (void)endEditing;
@end
@implementation NSWindow (Editing)
- (void)endEditing
{
// Save the current first responder, respecting the fact
// that it might conceptually be the delegate of the
// field editor that is "first responder."
id oldFirstResponder = [oMainDocumentWindow firstResponder];
if ((oldFirstResponder != nil) &&
[oldFirstResponder isKindOfClass:[NSTextView class]] &&
[(NSTextView*)oldFirstResponder isFieldEditor])
{
// A field editor's delegate is the view we're editing
oldFirstResponder = [oldFirstResponder delegate];
if ([oldFirstResponder isKindOfClass:[NSResponder class]] == NO)
{
// Eh ... we'd better back off if
// this thing isn't a responder at all
oldFirstResponder = nil;
}
}
// Gracefully end all editing in our window (from Erik Buck).
// This will cause the user's changes to be committed.
if([oMainDocumentWindow makeFirstResponder:oMainDocumentWindow])
{
// All editing is now ended and delegate messages sent etc.
}
else
{
// For some reason the text object being edited will
// not resign first responder status so force an
/// end to editing anyway
[oMainDocumentWindow endEditingFor:nil];
}
// If we had a first responder before, restore it
if (oldFirstResponder != nil)
{
[oMainDocumentWindow makeFirstResponder:oldFirstResponder];
}
}
@end
因此,如果您有一个针对 View Controller 的方法 -save:
的“保存”按钮,您将调用
- (IBAction)save:(id)sender
{
[[[self view] window] endEditing];
//at this point, all properties bound to text fields have the same
//value as the contents of the text fields.
//save stuff...
}
关于objective-c - 更新从文本字段绑定(bind)的属性,无需按 Enter 键,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14049913/