Question

我试图实现一个提供地图标记动画的库，但是当我尝试添加一些高级方法时，它会在第二个方法上引发错误＆＃34; .withFillColor（Color.BLUE）＆＃34;其中说：错误：无法取消引用虚空。

// mMap is GoogleMap object, latLng is the location on map from which ripple should start
    actualUbicacion = new LatLng(3.385264, -76.526551);
    mapRipple = new MapRipple(mMap, actualUbicacion, this)
            .withNumberOfRipples(3) //int
            .withFillColor(Color.BLUE) //here I get the error
            .withStrokeColor(Color.BLACK) //if I delete the previous one, the next one gets the error
            .withStrokewidth(10)      // 10dp
            .withDistance(2000)      // 2000 metres radius
            .withRippleDuration(12000)    //12000ms
            .withTransparency(0.5f);
    mapRipple.startRippleMapAnimation();      //in onMapReadyCallBack

Error:(623, 17) error: void cannot be dereferenced

Answer 1

From Code

返回类型为void

public void withNumberOfRipples(int numberOfRipples) {
    if (numberOfRipples > 4 || numberOfRipples < 1)
        numberOfRipples = 4;
    this.numberOfRipples = numberOfRipples;
}

所以你不能链接你的函数调用，你需要调用MapRipple实例上的每个函数，而不是void

解决方案：减少对单一级别的调用

mapRipple = new MapRipple(mMap, actualUbicacion, this);
mapRipple.withNumberOfRipples(3);
mapRipple.withFillColor(Color.BLUE);
mapRipple.withStrokeColor(Color.BLACK);
mapRipple.withStrokewidth(10);      // 10dp
mapRipple.withDistance(2000);      // 2000 metres radius
mapRipple.withRippleDuration(12000);    //12000ms
mapRipple.withTransparency(0.5f);
mapRipple.startRippleMapAnimation();

错误：无法取消引用void

1 个答案: