我有一个文本字段,并将其绑定到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值?
默认情况下,a 的值绑定NSTextField
不持续更新。要解决此问题,您需要在选择文本字段后,选中“值”标题下的“绑定检查器”中的“连续更新值”框:
However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(例如“保存”或“确定”)时更新文本字段绑定的属性。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 提供了这种方法的极其有用的实现 http://www.red-sweater.com/blog/229/stay-responsive:
@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,如果您有一个针对视图控制器方法的“保存”按钮-save:
,你会打电话给
- (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...
}
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