NSComboBox，此功能实现的效果图如下图所示：
1. 首先调用NSComboBox的父类NSTextField的delegate方法，实现实时输入监测。其中比较关键的方法是-(void)controlTextDidChange:(NSNotification*)notification,这个方法可以实现输入内容的实时监测。
-(void)controlTextDidChange:(NSNotification*)notification
{
id object = [notification object];
[object setComplete:YES];//这个函数可以实现自动匹配功能
}
2. 可以看到，在NSComboBox控件的右边有一个标有下三角的按钮，这个按钮在鼠标点击后才弹出下拉菜单来，但是我们在输入的时候没有实现鼠标事件，所以下来菜单无法弹出，因此需要模拟鼠标事件-(void)mouseDown:(NSEvent*)theEvent，但是这个按钮是NSComboBoxCell中的私有变量，所以我们重新创建一个类，这个类继承NSComboBoxCell，这样我们就可以应用它的私有变量了。
继承NSComboBox类：
@interface ComboBoxCell : NSComboBoxCell
{
}
- (void)popUpList;
- (void)closePopUpWindow;
- (BOOL)isPopUpWindowVisible;
@end
@implementation ComboBoxCell
- (void)popUpList
{
if ([self isPopUpWindowVisible])
{
return;
}
else
{
[_buttonCell performClick:nil];//模拟鼠标事件
}
}
- (void)closePopUpWindow
{
if ([self isPopUpWindowVisible])
{
[_popUp close];
}
}
- (BOOL)isPopUpWindowVisible
{
return [_popUp isVisible];
}
@end
3. 实现NSComboBox类的Datasource方法：
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)aComboBox;
- (id)comboBox:(NSComboBox *)aComboBox objectValueForItemAtIndex:(NSInteger)index;
- (NSUInteger)comboBox:(NSComboBox *)aComboBox indexOfItemWithStringValue:(NSString *)string;
这是Datasource方法，我们需要重写此方法。下面是三个方法的实现，方法中的结构体可以根据用户的需要自定义。
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)aComboBox
{
NSInteger row = 0;
if (currentBoxIndex_ == -1)
{
return row;
}
DBBoxManager *currentBox = [[DBManager defaultDBManager] boxAtIndex:currentBoxIndex_];
if ([vendorControl_ isEqual:aComboBox])
{
row = [currentBox userDefineVenderInfos].count;
}
else if ([categoryControl_ isEqual:aComboBox])
{
row = [currentBox userDefineCategoryInfos].count;
}
else if ([paymentControl_ isEqual:aComboBox])
{
row = [currentBox userDefinePaymentInfos].count;
}
else if ([purposeControl_ isEqual:aComboBox])
{
row = [currentBox userDefinePurposeInfos].count;
}
else if ([categorySelectBtn_ isEqual:aComboBox])
{
row = [currentBox userDefineCategoryInfos].count;
}
else if([vendorSelectBtn_ isEqual:aComboBox])
{
row = [currentBox userDefineVenderInfos].count;
}
row = row + 1;
return row;
}
- (id)comboBox:(NSComboBox *)aComboBox objectValueForItemAtIndex:(NSInteger)index
{
NSString *content = nil;
if (currentBoxIndex_ == -1)
{
return content;
}
NSMutableArray *array = nil;
DBBoxManager *currentBox = [[DBManager defaultDBManager] boxAtIndex:currentBoxIndex_];
if ([vendorControl_ isEqual:aComboBox])
{
array = [currentBox userDefineVenderInfos];
}
else if ([categoryControl_ isEqual:aComboBox])
{
array = [currentBox userDefineCategoryInfos];
}
else if ([paymentControl_ isEqual:aComboBox])
{
array = [currentBox userDefinePaymentInfos];
}
else if ([purposeControl_ isEqual:aComboBox])
{
array = [currentBox userDefinePurposeInfos];
}
else if ([categorySelectBtn_ isEqual:aComboBox])
{
array = [currentBox userDefineCategoryInfos];
}
else if ([vendorSelectBtn_ isEqual:aComboBox])
{
array = [currentBox userDefineVenderInfos];
}
if (index == 0)
{
content = @"";
}
else
{
NSDictionary *dic = [array objectAtIndex:index - 1];
content = (NSString *)[dicobjectForKey:kUserDefinedBoxValue];
}
return content;
}
- (NSUInteger)comboBox:(NSComboBox *)aComboBox indexOfItemWithStringValue:(NSString *)string
{
DBBoxManager *currentBox = [[DBManager defaultDBManager] boxAtIndex:currentBoxIndex_];
NSMutableArray *comboxList = nil;
if ([aComboBox isEqual:vendorControl_])
{
comboxList = [currentBox userDefineVenderInfos];
}
else if([aComboBox isEqual:categoryControl_])
{
comboxList = [currentBox userDefineCategoryInfos];
}
else if([aComboBox isEqual:paymentControl_])
{
comboxList = [currentBox userDefinePaymentInfos];
}
else if([aComboBox isEqual:purposeControl_])
{
comboxList = [currentBox userDefinePurposeInfos];
}
NSMutableArray *newList = [[[NSMutableArray alloc] initWithCapacity:0] autorelease];
[newList addObject:@""];
for (int i = 0; i < [comboxList count]; i++)
{
NSString *name = [[comboxList objectAtIndex:i] objectForKey:kUserDefinedBoxValue];
[newList addObject:name];
}
return [newList indexOfObject:string];
}
做到这里，这个功能就基本实现了，本文中的代码来自正在开发的工程，读者只需替换响应的结构体，即可实现功能。
