Question

我有问题将图像设置为PictureBox如果它是空的...我尝试了几种不同的方法，我总是得到相同的异常。通过阅读这里和网上的文章，这应该有效，但它不会......

我已经宣布了6个PB阵列......

    PictureBox[] red1 = new PictureBox[4];
    PictureBox[] red2 = new PictureBox[4];
    PictureBox[] red3 = new PictureBox[4];
    PictureBox[] red4 = new PictureBox[4];
    PictureBox[] red5 = new PictureBox[4];
    PictureBox[] red6 = new PictureBox[4];

在FormLoad事件中，这些数组使用appropriet PBs填充......

     PictureBox[] red1 = { pok11, pok12, pok13, pok14 };
     PictureBox[] red2 = { pok21, pok22, pok23, pok24 };
     PictureBox[] red3 = { pok31, pok32, pok33, pok34 };
     PictureBox[] red4 = { pok41, pok42, pok43, pok44 };
     PictureBox[] red5 = { pok51, pok52, pok53, pok54 };
     PictureBox[] red6 = { pok61, pok62, pok63, pok64 };

当我调用方法来使用它们时会抛出异常......

呼叫：

     DodajSLIKU(Properties.Resources.HERCv2, red1);

方法：

    public void DodajSLIKU(Image slika, PictureBox[] t)
    {            
        if (t[0].Image == null)   //where exception occures.
            t[0].Image = slika;
        else if (t[1].Image == null)
            t[1].Image = slika;
        else if (t[2].Image == null)
            t[2].Image = slika;
        else if (t[3].Image == null)
            t[3].Image = slika;
        else
            return;
    }

我在哪里做错了？感谢...

Answer 1

更改您的方法签名，如下所示：

public void DodajSLIKU(Image slika, PictureBox[] t)
        {
            foreach (var item in t)
            {
                if (item != null)
                {
                    if (item.Image == null)  
                        item.Image = slika;
                }
            }            
        }

检查picturebox是否为空会给出“对象引用未设置为对象的实例”。例外

1 个答案: