百度地圖繪製軌跡

最近項目須要作到這個功能，寫篇博客，只是自我總結，沒有時間寫demo，先上效果圖：

先說思路，咱們的項目是一秒走一個經緯度及畫一條線段，可前進後退，先用定時器重複執行一個方法，方法就處理小點前進的動畫，繪製路線我是每次清空，從新繪製的，設置一個全局變量，記錄下當下小點移動到哪一個位置，此次好進行前進後退的處理，思路其實很簡單的

#pragma mark---------劃線代理回調----------
- (BMKOverlayView*)mapView:(BMKMapView *)map viewForOverlay:(id<BMKOverlay>)overlay
{
    if ([overlay isKindOfClass:[BMKPolyline class]]) {
        BMKPolylineView* polylineView = [[BMKPolylineView alloc] initWithOverlay:overlay];
        polylineView.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:1];
        polylineView.strokeColor = [[UIColor blueColor] colorWithAlphaComponent:0.7];
        polylineView.lineWidth = 2.0f;
        return polylineView;
    }
    return nil;
}
複製代碼

BMKPointAnnotation * antion = [[BMKPointAnnotation alloc]init];
    antion.title = @"";
    antion.coordinate = _coors[_index-1];
    [_mapView addAnnotation:antion];
    
    
    //重複再添加一次起點和終點
    KJBHomeHistoricalTrackAnnotation * Annotation = [[KJBHomeHistoricalTrackAnnotation alloc]init];
    Annotation.type =0;
    Annotation.coordinate = _coors[0];
    [_mapView addAnnotation:Annotation];
    
    
    Annotation = [[KJBHomeHistoricalTrackAnnotation alloc] init];
    Annotation.type = 1;
    Annotation.coordinate = _coors[Max];
    [_mapView addAnnotation:Annotation];
    //軌跡繪製
    BMKPolyline  * polyline = [BMKPolyline polylineWithCoordinates:_coors count:_index];
    [_mapView addOverlay:polyline];
複製代碼

// 根據polyline設置地圖範圍
- (void)mapViewFitPolyLine:(BMKPolyline *) polyLine {
    CGFloat ltX, ltY, rbX, rbY;
    if (polyLine.pointCount < 1) {
        return;
    }
    BMKMapPoint pt = polyLine.points[0];
    ltX = pt.x; ltY = pt.y;
    rbX = pt.x; rbY = pt.y;
    for (int i = 1; i < polyLine.pointCount; i++) {
        BMKMapPoint pt = polyLine.points[i];
        if (pt.x < ltX) {
            ltX = pt.x;
        }
        if (pt.x > rbX) {
            rbX = pt.x;
        }
        if (pt.y > ltY) {
            ltY = pt.y;
        }
        if (pt.y < rbY) {
            rbY = pt.y;
        }
    }
    BMKMapRect rect;
    rect.origin = BMKMapPointMake(ltX , ltY);
    rect.size = BMKMapSizeMake(rbX - ltX, rbY - ltY);
    [_mapView setVisibleMapRect:rect];
}複製代碼

到這裏，代碼就結束了，在viewWillDisappear中別忘了設置_mapView.delegate爲nil，

定時器也要及時釋放調