iOS--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)(),而后copy一个myBlock类型的属性:
@property(nonatomic ,copy) myBlock block;
3>.在B控制器中建立A控制器,而后调用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>.调用之后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,而且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做为参数的方法
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，但在其余城市找到结果时，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