点标记用来在地图上标记任何位置，例如用户位置、车辆位置、店铺位置等一切带有位置属性的事物。

百度地图iOS SDK 提供的点标记功能包含两大部分，一部分是点（俗称Annotation）、另一部分是浮于点上方的信息窗体（俗称 PaopaoView）。同时，SDK对Annotation和PaopaoView封装了大量的触发事件，例如点击事件、长按事件、拖拽事件。

Annotation和 PaopaoView 有默认风格，同时也支持自定义。

iOS地图SDK预置了基本的标注点（BMKPointAnnotation）和一个大头针标注View（BMKPinAnnotationView），您可以直接使用来显示标注。

iOS地图SDK提供的大头针标注BMKPinAnnotationView，通过它可以设置大头针颜色、是否显示动画等。

BMKPointAnnotation* annotation = [[BMKPointAnnotation alloc]init];
annotation.coordinate = CLLocationCoordinate2DMake(39.915, 116.404);
//设置标注的标题
annotation.title = @"北京";
//副标题
annotation.subtitle = @"天安门";
[_mapView addAnnotation:annotation];

实现 <BMKMapViewDelegate> 协议中的 mapView:viewForAnnotation:回调函数，设置标注样式。代码如下所示：

#pragma mark - BMKMapViewDelegate
- (BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id <BMKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[BMKPointAnnotation class]])
    {
        static NSString *reuseIndetifier = @"annotationReuseIndetifier";
        BMKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseIndetifier];
        if (annotationView == nil)
        {
            annotationView = [[BMKAnnotationView alloc] initWithAnnotation:annotation
                                                              reuseIdentifier:reuseIndetifier];
        }
        return annotationView;
    }
    return nil;
}

在地图显示对应的标注点，点击标注弹出气泡，效果如图：

iOS 地图SDK可自定义标注（包括自定义标注图标和自定义气泡图标），均通过BMKAnnotationView来实现。

若大头针样式的标注不能满足您的需求，您可以自定义标注图标。代码如下：

#pragma mark - BMKMapViewDelegate
- (BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id <BMKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[BMKPointAnnotation class]])
    {
        static NSString *reuseIndetifier = @"annotationReuseIndetifier";
        BMKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseIndetifier];
        if (annotationView == nil)
        {
            annotationView = [[BMKAnnotationView alloc] initWithAnnotation:annotation
                                                              reuseIdentifier:reuseIndetifier];
        }

        annotationView.image = [UIImage imageNamed:@"poi.png"];
        return annotationView;
    }
    return nil;
}

效果如图：

气泡在iOS中又称为PaopaoView，它由背景和气泡内容构成。

自定义气泡类完整代码如下：

#import <UIKit/UIKit.h>

@interface CustomPaopaoView : UIView
@property (nonatomic, strong) UIImage *image; //商户图
@property (nonatomic, copy) NSString *title; //商户名
@property (nonatomic, copy) NSString *subtitle; //地址
@end

#import "CustomPaopaoView.h"
#define kPortraitMargin     5
#define kPortraitWidth      50
#define kPortraitHeight     50
#define kTitleWidth         120
#define kTitleHeight        20
#define kArrorHeight 0

@interface CustomPaopaoView ()

@property (nonatomic, strong) UIImageView *portraitView;
@property (nonatomic, strong) UILabel *subtitleLabel;
@property (nonatomic, strong) UILabel *titleLabel;
@end
@implementation CustomPaopaoView

#pragma mark - draw rect

- (void)drawRect:(CGRect)rect
{
[self drawInContext:UIGraphicsGetCurrentContext()];

self.layer.shadowColor = [[UIColor blackColor] CGColor];
self.layer.shadowOpacity = 1.0;
self.layer.shadowOffset = CGSizeMake(0.0f, 0.0f);
}

- (void)drawInContext:(CGContextRef)context
{
CGContextSetLineWidth(context, 2.0);
CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0.3 green:0.3 blue:0.3 alpha:0.8].CGColor);

    [self getDrawPath:context];
    CGContextFillPath(context);
}
- (void)getDrawPath:(CGContextRef)context
{
    CGRect rrect = self.bounds;
    CGFloat radius = 6.0;
    CGFloat minx = CGRectGetMinX(rrect),
    midx = CGRectGetMidX(rrect),
    maxx = CGRectGetMaxX(rrect);
    CGFloat miny = CGRectGetMinY(rrect),
    maxy = CGRectGetMaxY(rrect)-kArrorHeight;

    CGContextMoveToPoint(context, midx+kArrorHeight, maxy);
    CGContextAddLineToPoint(context,midx, maxy+kArrorHeight);
    CGContextAddLineToPoint(context,midx-kArrorHeight, maxy);

    CGContextAddArcToPoint(context, minx, maxy, minx, miny, radius);
    CGContextAddArcToPoint(context, minx, minx, maxx, miny, radius);
    CGContextAddArcToPoint(context, maxx, miny, maxx, maxx, radius);
    CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
    CGContextClosePath(context);
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        [self initSubViews];
    }
    return self;
}

- (void)initSubViews
{
    // 添加图片，即商户图
    self.portraitView = [[UIImageView alloc] initWithFrame:CGRectMake(kPortraitMargin, kPortraitMargin, kPortraitWidth, kPortraitHeight)];

    self.portraitView.backgroundColor = [UIColor blackColor];
    [self addSubview:self.portraitView];

    // 添加标题，即商户名
    self.titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(kPortraitMargin * 2 + kPortraitWidth, kPortraitMargin, kTitleWidth, kTitleHeight)];
    self.titleLabel.font = [UIFont boldSystemFontOfSize:14];
    self.titleLabel.textColor = [UIColor whiteColor];
    self.titleLabel.text = self.title;
    [self addSubview:self.titleLabel];

    // 添加副标题，即商户地址
    self.subtitleLabel = [[UILabel alloc] initWithFrame:CGRectMake(kPortraitMargin * 2 + kPortraitWidth, kPortraitMargin * 2 + kTitleHeight, kTitleWidth, kTitleHeight)];
    self.subtitleLabel.font = [UIFont systemFontOfSize:12];
    self.subtitleLabel.textColor = [UIColor lightGrayColor];
    self.subtitleLabel.text = self.subtitle;
    [self addSubview:self.subtitleLabel];
}

- (void)setTitle:(NSString *)title
{
    self.titleLabel.text = title;
}

- (void)setSubtitle:(NSString *)subtitle
{
    self.subtitleLabel.text = subtitle;
}

- (void)setImage:(UIImage *)image
{
    self.portraitView.image = image;
}

@end

以上就是自定义气泡类的全部示例代码，在点击标注时实现弹出自定义的气泡的效果，还需要在BMKMapView的代理方法mapView: viewForAnnotation:设置自定义的paopaoView，完整代码如下：

#pragma mark - BMKMapViewDelegate
- (BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id <BMKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[BMKPointAnnotation class]])
    {
        static NSString *reuseIndetifier = @"annotationReuseIndetifier";
        BMKAnnotationView *annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseIndetifier];
        if (annotationView == nil)
        {
            annotationView = [[BMKAnnotationView alloc] initWithAnnotation:annotation
                                                              reuseIdentifier:reuseIndetifier];
        }

        annotationView.image = [UIImage imageNamed:@"poi.png"];

        annotationView.canShowCallout = YES;
        CustomPaopaoView *customPopView = [[CustomPaopaoView alloc] init];
        customPopView.frame = CGRectMake(0, 0, 120.0f, 70.0f);
        customPopView.image = [UIImage imageNamed:@"poi.png"];
        customPopView.title = @"北京";
        customPopView.subtitle = @"天安门";

        BMKActionPaopaoView *pView = [[BMKActionPaopaoView alloc] initWithCustomView:customPopView];
        pView.backgroundColor = [UIColor lightGrayColor];
        pView.frame = customPopView.frame;
        annotationView.paopaoView = pView;
        return annotationView;
    }
    return nil;
}

效果如图：

//删除指定的单个点标记
[_mapView removeAnnotation:annotation];

/**
 *向地图窗口添加一组标注，需要实现BMKMapViewDelegate的-mapView:viewForAnnotation:函数来生成标注对应的View
 *@param annotations 要添加的标注数组
 */
[_mapView addAnnotations:annotations];

/**
 *移除一组标注
 *@param annotation 要移除的标注数组
 */
[_mapView removeAnnotations:annotations];

Since 6.5.0 iOS地图SDK起支持点标记碰撞策略功能

BMKAnnotationView新增以下属性，整体碰撞策略优先级：层级限制＞强制展示＞碰撞优先级＞展示优先级＞添加顺序

NSMutableArray *annotations = [NSMutableArray array]; 
  for (NSInteger i = 0; i < 20; i++) { 
    double lat =  (arc4random() % 100) * 0.001; 
    double lon =  (arc4random() % 100) * 0.001; 
    BMKPointAnnotation *annotation = [[BMKPointAnnotation alloc] init]; 
    annotation.coordinate = CLLocationCoordinate2DMake(_basicAnnotationCoordinate.latitude + lat, _basicAnnotationCoordinate.longitude + lon); 
    annotation.title = @"绿"; 
    [annotations addObject:annotation]; 
} 
[self.mapView addAnnotations:annotations];

实现 <BMKMapViewDelegate> 协议中的 mapView:viewForAnnotation:回调函数，设置标注样式。代码如下所示：

#pragma mark - BMKMapViewDelegate 
  - (BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id<BMKAnnotation>)annotation { 
     BMKPinAnnotationView *pinAnnotationView = (BMKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:annotationViewIdentifier]; 
    if (!pinAnnotationView) { 
        pinAnnotationView = [[BMKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:annotationViewIdentifier]; 
    }
    if ([annotation.title isEqualToString:@"红"]) { 
        pinAnnotationView.pinColor = BMKPinAnnotationColorRed;
        // 强制展示 
        pinAnnotationView.isForceDisplay = YES; 
    } else if ([annotation.title isEqualToString:@"紫"]) { 
        pinAnnotationView.pinColor = BMKPinAnnotationColorPurple; 
        // 最大展示级别 
        pinAnnotationView.displayMaxLevel = 19; 
        // 最小展示级别 
        pinAnnotationView.displayMinLevel = 10; 
    } else { 
        pinAnnotationView.pinColor = BMKPinAnnotationColorGreen; 
    }
        // 开启碰撞检测 
    pinAnnotationView.isOpenCollisionDetection = YES; 
    return pinAnnotationView;
}

效果如下：