block使用总结

1.block使用步骤:

1>.有两个控制器,主动传值或者提供方法的控制器A,接受值的控制器B
2>.让A控制器typedef void(^myBlock)(),然后copy一个myBlock类型的属性:
@property(nonatomic ,copy) myBlock block;
3>.在B控制器中创建A控制器,然后调用A控制器的方法
4>.在A控制器方法中,记录block:self.block = block;
5>.在合适的地方调用block:self.block(poiResultList.poiInfoList);
6>.调用以后block参数里边已经有值,这个时候在B控制器中调用A控制器的方法中参数block开始执行,并且block中参数也已经有值.

2.block原理篇:

1>.谁要传值,谁声明和定义block以及把block作为参数的方法
2>.传值方记录下来block,在合适的时候调用
3>.接受值方,调用方法,等传值方调用block的时候才会在代码块中拿到block传过来的参数值.

3.demo

#import"TSYBaiduTool.h"

   @interfaceTSYBaiduTool()
   @property(nonatomic,copy) Blockblock;
   /** poi检索对象*/
   @property(nonatomic,strong)BMKPoiSearch*searcher;
  @end
  
  @implementationTSYBaiduTool
  single_implementation(TSYBaiduTool)
  - (void)getPoiWithCeneter:(CLLocationCoordinate2D)centerkey:(NSString*)key Result:(Block)block{
  //记录block self.block=block; 
 //初始化检索对象 _searcher=[[BMKPoiSearch alloc] init]; 
  _searcher.delegate=self;  
 //发起检索
  BMKNearbySearchOption*option = [[BMKNearbySearchOption alloc] init]; 
  option.pageIndex=0;   option.pageCapacity=20; option.location= center; option.keyword= key; 
  BOOLflag = [_searcherpoiSearchNearBy:option]; 
  if(flag){NSLog(@"周边检索发送成功");}else
  {NSLog(@"周边检索发送失败");}  

#import"TSYBaiduTool.h"

   @interfaceTSYBaiduTool()
   @end
   @implementationTSYBaiduTool
   - (void)addAnnotationCenter:(CLLocationCoordinate2D)centertitle:(NSString*)title subTitle:(NSString*)subTile toMapView:(BMKMapView*)mapView{
   //添加一个PointAnnotation 
   BMKPointAnnotation* annotation = [[BMKPointAnnotation alloc] init];
   annotation.coordinate= center; 
   annotation.title= title; 
   annotation.subtitle= subTile; 
   [mapViewaddAnnotation:annotation];  }

#import"TSYBaiduTool.h"

   @interfaceTSYBaiduTool()
   @end
   @implementationTSYBaiduTool
   #pragmamark - BMKPoiSearchDelegate  
   //实现PoiSearchDeleage处理回调结果 
    -(void)onGetPoiResult:(BMKPoiSearch*)searcherresult:(BMKPoiResult*)poiResultListerrorCode:(BMKSearchErrorCode)error{ 
    if(error ==BMK_SEARCH_NO_ERROR) {
      //在此处理正常结果    
    self.block(poiResultList.poiInfoList);
    } else if(error ==BMK_SEARCH_AMBIGUOUS_KEYWORD){
     //当在设置城市未找到结果，但在其他城市找到结果时，回调建议检索城市列表 
      //result.cityList;  NSLog(@"起始点有歧义");  }else{ 
       NSLog(@"抱歉，未找到结果--%zd", error);} 
     }
   @end

#import"Singleton.h"

   #import typedef void(^Block) (NSArray*result);
   @interfaceTSYBaiduTool :NSObject
   single_interface(TSYBaiduTool)
   -(void)getPoiWithCeneter:(CLLocationCoordinate2D)centerkey:(NSString*)key Result:(Block)block;
   -(void)addAnnotationCenter:(CLLocationCoordinate2D)centertitle:(NSString*)title subTitle:(NSString*)subTile toMapView:(BMKMapView*)mapView;
    @end

#import"ViewController.h"

  #import"TSYBaiduTool.h"
  @interfaceViewController()
  @property(weak,nonatomic) IBOutlet BMKMapView*mapView;
  @end

 @implementationViewController
 - (void)viewDidLoad {
 [super viewDidLoad];
 self.mapView.delegate=self;
 }
 #pragmark - BMKMapViewDelegate
 /**
*长按地图时调用
*  @param mapView    地图
*  @param coordinate点对应的经纬度
*/
 -(void)mapview:(BMKMapView*)mapView onLongClick:(CLLocationCoordinate2D)coordinate{
//调整地图显示区域
 BMKCoordinateSpanspan = BMKCoordinateSpanMake(0.075418,0.051922);
 BMKCoordinateRegionregion = BMKCoordinateRegionMake(coordinate, span);
  [mapViewsetRegion:regionanimated:YES];
  //poi检索
   [[TSYBaiduToolsharedTSYBaiduTool]getPoiWithCeneter:coordinatekey:@"小吃"Result:^(NSArray *result) {     
 [resultenumerateObjectsUsingBlock:^(BMKPoiInfo*_Nonnullobj,NSUIntegeridx,BOOL*_Nonnullstop) {
//添加大头针
   [[TSYBaiduToolsharedTSYBaiduTool]addAnnotationCenter:obj.pttitle:obj.namesubTitle:obj.addresstoMapView:self.mapView];
}];
}];
}
@end