更改布局空指针异常的背景

Question

我试图通过随机数组的drawable来交替线性布局的背景图像，但仍然得到一个空指针异常：

Integer[] images = {R.drawable.image1,R.drawanle.image2};
Random whichImage = new Random();
Int theImage= whichImage.nextInt(1);

View myView= findViewById(R.layout.splash);
myView.setBackgroundResource
(imageSelection[theImage]);
setContentView(myView);

空指针出现在myView.setBackground .....

干杯.....

Answer 1

您无法将int传递给后台资源。

而不是

myView.setBackgroundResource(imageSelection[theImage]);

试

myView.setBackgroundResource(getResources().getDrawable(imageSelection[theImage]));

Answer 2

替换

Integer[] images =    
{R.drawable.image1,R.drawanle.image2};

用这个

int[] images = new int[] {R.drawable.image1,R.drawanle.image2};

Answer 3

Integer[] images =     {R.drawable.image1,R.drawanle.image2};
Random whichImage = new Random();

Int theImage= whichImage.nextInt(1);

setContentView(R.Layout.splash);
View myView= findViewById(R.id.view);

myView.setBackgroundResource (imageSelection[theImage]);

Answer 4

//Should this
Int theImage= whichImage.nextInt(1);
// be replaced with
Int theImage= whichImage.nextInt(images.length);

//Then move your setBackgroundResource call to after you call the setContentView method.  
setContentView(myView);
myView.setBackgroundResource(image[theImage]);

Answer 5

谢谢，我的View myView参考文件有问题，我认为这是返回null。当我使用它来获得背景时它运行良好：

this.getWindow().setBackgroundDrawableResource(imageSelection[theImage]);