iOS开发UISearchBar的使用及searchBar的成员属性解释

最近研究了一下UISearchBar，下面了解下它的属性吧

属性	作用
UIBarStyle barStyle	控件的样式
id<UISearchBarDelegate> delegate	设置控件的委托
NSString *text	控件上面的显示的文字
NSString *prompt	显示在顶部的单行文字，通常作为一个提示行
NSString *placeholder	半透明的提示文字，输入搜索内容消失
BOOL showsBookmarkButton	是否在控件的右端显示一个书的按钮(没有文字的时候)
BOOL showsCancelButton	是否显示cancel按钮
BOOL showsSearchResultsButton	是否在控件的右端显示搜索结果按钮(没有文字的时候)
BOOL searchResultsButtonSelected	搜索结果按钮是否被选中
UIColor *tintColor	bar的颜色(具有渐变效果)
BOOL translucent	指定控件是否会有透视效果
UITextAutocapitalizationType autocapitalizationType	设置在什么的情况下自动大写
UITextAutocorrectionType autocorrectionType	对于文本对象自动校正风格
UIKeyboardType keyboardType	键盘的样式
NSArray *scopeButtonTitles	搜索栏下部的选择栏，数组里面的内容是按钮的标题
NSInteger selectedScopeButtonIndex	搜索栏下部的选择栏按钮的个数
BOOL showsScopeBar	控制搜索栏下部的选择栏是否显示出来

代理列表：

编辑代理方法

– searchBar:textDidChange:

– searchBar:shouldChangeTextInRange:replacementText:

– searchBarShouldBeginEditing:

– searchBarTextDidBeginEditing:

– searchBarShouldEndEditing:

– searchBarTextDidEndEditing:

点击按钮

– searchBarBookmarkButtonClicked:

– searchBarCancelButtonClicked:

– searchBarSearchButtonClicked:

– searchBarResultsListButtonClicked:

范围代理

– searchBar:selectedScopeButtonIndexDidChange:

searchBar的范围控件showsScopeBar，官方学名叫Scope Buttons。

首先就要设置这个属性：

self.searchBar.showsScopeBar = YES;

然后要给他添加按钮。比如说，这样：self.searchBar.scopeButtonTitles = [NSArray arrayWithObjects:@"BOY",@"GIRL",@"ALL",nil];

还有一个很重要的事情就是我们要实现这个代理UISearchBarDelegate里的这个方法searchBar:selectedScopeButtonIndexDidChange:。告诉表格，你选择的范围是啥。

还有要是设置默认选择哪个按钮的话，要设置这个属性,像这样就是默认选中第1个啦。

self.searchBar.selectedScopeButtonIndex = 0;

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
NSLog(@"shouldReloadTableForSearchString: %@", searchString);
if ((controller.searchBar.selectedScopeButtonIndex != 0) || // 第一个search条件
(searchString && [searchString length])) {
[self maybeBeginSearch];
return NO;
} else {
self.currentResult = nil;
return YES;
}
}

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchScope:(NSInteger)searchOption
{
NSLog(@"shouldReloadTableforSearchScope: %d", searchOption);
if ((searchOption != 0) ||
(controller.searchBar.text && [controller.searchBar.text length])) {
[self maybeBeginSearch];
return NO;
} else {
self.currentResult = nil;
return YES;
}
}

- (void)searchDisplayController:(UISearchDisplayController *)controller didShowSearchResultsTableView:(UITableView *)tableView
{
// make the activity indicator a sibling of the tableView, so that it can
// be displayed on top of it
[[tableView superview] addSubview:_activityView];
}

- (void)maybeBeginSearch
{
// cancel any existing timer
if (_searchTimer) {
NSLog(@"Cancelling existing timer");
[_searchTimer invalidate];
[_searchTimer release];
}

// 创建一个timer
_searchTimer = [[NSTimer scheduledTimerWithTimeInterval:0.3
target:self
selector:@selector(beginTimerSearch:)
userInfo:nil
repeats:NO] retain];
}

- (void)beginTimerSearch:(NSTimer*)timer
{
if (timer == _searchTimer) {
[_searchTimer invalidate];
[_searchTimer release];
_searchTimer = nil;
[self beginSearch];
}
}

- (void)beginSearch
{
NSLog(@"Begin search for %@ with scope %d", self.searchDisplayController.searchBar.text,
self.searchDisplayController.searchBar.selectedScopeButtonIndex);

// in case one is running already
[self.currentRequest cancel];
self.currentRequest = nil;

NSInteger scopeIndex = self.searchDisplayController.searchBar.selectedScopeButtonIndex;
if (scopeIndex == 0) {
NSString* searchString = self.searchDisplayController.searchBar.text;

if (searchString && [searchString length]) {
_activityView.hidden = NO;
if ([searchString length]>5 &&
![searchString hasSuffix:@"*"])
searchString = [NSString stringWithFormat:@"%@*", searchString];
self.currentRequest = [[FreebaseSession session] search:searchString
name:@"suggest"
delegate:self
didFinishSelector:@selector(searchFinished:)
options:[NSDictionary dictionaryWithObjectsAndKeys:
@"/common/topic", @"type",
nil]];
}
else
NSLog(@"No search string: %@", searchString);
}
else {
[self beginGeosearch];
}
}

- (void)beginGeosearch {
NSLog(@"beginGeosearch");
_activityLabel.text = @"Locating...";
_activityView.hidden = NO;

// this is what I want to do:
// self.searchDisplayController.searchResultsTableView.hidden = NO;

// this is moronic, but it makes the table display :(
NSString* searchString;
if (![self.searchDisplayController.searchBar.text length])
self.searchDisplayController.searchBar.text = @" ";
else
searchString = self.searchDisplayController.searchBar.text;

if (!_awaitingLocation) {
NSLog(@"Awaiting location, so queing up a search");
_awaitingLocationForSearch = YES;
_awaitingLocation = YES;
[_locationManager startUpdatingLocation];
} else if (!_currentLocation) {
NSLog(@"Not awaiting, but still missing _currentLocation");
// we're awaiting a location, but haven't yet started searching
_awaitingLocationForSearch = YES;
} else {
NSLog(@"Kicking off a geosearch...");
_activityLabel.text = @"Loading...";
_awaitingLocationForSearch = NO;
// ok, we have a location, lets search!
CLLocationDegrees latitude = _currentLocation.coordinate.latitude;
CLLocationDegrees longtitude = _currentLocation.coordinate.longitude;
NSDictionary* geoJsonLocation = [NSDictionary dictionaryWithObjectsAndKeys:
@"Point", @"type",
[NSArray arrayWithObjects:
[NSNumber numberWithDouble:longtitude],
[NSNumber numberWithDouble:latitude], nil],
@"coordinates",
nil];
NSString* locationString = [geoJsonLocation JSONRepresentation];

NSArray *mql_output = [NSArray arrayWithObject:
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNull null], @"id",
[NSNull null], @"name",
[NSArray arrayWithObject:
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNull null], @"id",
[NSNull null], @"name",
[NSNumber numberWithBool:YES], @"optional", nil]], @"type",
nil]];

NSString *mql_output_string = [[mql_output JSONRepresentation] retain];
//[{"type": {"optional": "forbidden",
//          "id|=": ["/location/country", "/location/us_state", "/location/continent", "/location/us_county"]}}]

NSString* distance = [NSString stringWithFormat:@"%f",
DISTANCES[self.searchDisplayController.searchBar.selectedScopeButtonIndex]];

NSString *searchString = [self.searchDisplayController.searchBar.text
stringByTrimmingCharactersInSet:
[NSCharacterSet whitespaceAndNewlineCharacterSet]];

if (searchString && [searchString length]) {
NSString *geo_filter = [[NSDictionary dictionaryWithObjectsAndKeys:
distance, @"within",
locationString, @"location",
@"relevance", @"order_by",
@"/common/topic", @"type",
@"point", @"geometry_type",
nil] JSONRepresentation];
NSMutableDictionary*
options = [NSMutableDictionary dictionaryWithObjectsAndKeys:
geo_filter, @"geo_filter",
@"/common/topic", @"type",
nil];
if (self.mqlFilter)
[options setObject:self.mqlFilter forKey:@"mql_filter"];

NSLog(@"Search with geo_filter for %@ using %@", searchString, options);
if ([searchString length]>5 &&
![searchString hasSuffix:@"*"])
searchString = [NSString stringWithFormat:@"%@*", searchString];
self.currentRequest = [[FreebaseSession session] search:searchString
name:@"geo_relevance"
delegate:self
didFinishSelector:@selector(searchFinished:)
options:options];

} else {
NSMutableDictionary*
options = [NSMutableDictionary dictionaryWithObjectsAndKeys:
distance, @"within",
@"relevance", @"order_by",
mql_output_string, @"mql_output",
@"/common/topic", @"type",
@"point", @"geometry_type",
nil];
if (self.mqlFilter)
[options setObject:self.mqlFilter forKey:@"mql_filter"];
NSLog(@"Searching geo-only");
self.currentRequest = [[FreebaseSession session] geosearch:locationString
name:@"suggest"
delegate:self
didFinishSelector:@selector(geoSearchFinished:)
options:options];
}

[mql_output_string release];
}
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
self.currentLocation = newLocation;
NSLog(@"New location! %@", [newLocation description]);

if (_awaitingLocationForSearch) {
_awaitingLocationForSearch = NO;
[self beginGeosearch];
} else {
// ok, we can simply stop at this point -
// it means we've gotten a second location marker,
// possibly more accurate than before - no sense in
// burning the battery. We don't set _awaitingLocation now,
// because the one we've got is good enough
NSLog(@"Got a second location, that's good enough for now.");
[manager stopUpdatingLocation];
}
}

- (void)searchFinished:(id)result
{
NSLog(@"Search complete, %d items", [result count]);
self.currentResult = result;
_activityView.hidden = YES;
[self.searchDisplayController.searchResultsTableView reloadData];
}

- (void)geoSearchFinished:(NSDictionary*)result
{
self.currentResult = [result valueForKeyPath:@"features.properties"];
NSLog(@"Geosearch complete, %d items", [self.currentResult count]);
_activityView.hidden = YES;
[self.searchDisplayController.searchResultsTableView reloadData];
}

- (void)errorDidOccur:(id)result name:(NSString*)name
{
NSLog(@"oops...search error: %@", result);
_activityView.hidden = YES;
self.currentResult = [NSArray arrayWithObject:
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNull null], @"id",
[NSArray array], @"type",
[NSString stringWithFormat:@"Error: %@", result], @"name",
nil]];
[self.searchDisplayController.searchResultsTableView reloadData];
}

/*
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
}
*/

- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self.searchDisplayController setActive:YES animated:YES];
[self.searchDisplayController.searchBar becomeFirstResponder];
}

/*
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
}
*/
/*
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
}
*/