Android:使用setImageResource设置随机图像

Question

我需要一个使用setImageResource方法设置随机图像的帮助.在drawable文件夹中,我有一个名为photo0.jpg的jpeg文件,photo1.jpg ... photo99.jpg.以下代码有效:

int p = R.drawable.photo1;
image.setImageResource(p);

以上将显示photo1.jpg但我想显示一个随机图像.我尝试了以下但它不起作用.

String a = "R.drawable.photo";
int n = (int) (Math.random()*100)
String b = Integer.toString(n);
String c = a+b;
int p = Integer.parseInt(c);//checkpoint
image.setImageResource(p);

似乎字符串"R.drawable.photoXX"在检查点未被更改为整数.有人可以教我一个正确的代码吗？先感谢您.

Answer 1

Strings are pretty much evil when it comes to work like this due to the overhead costs. Since Android already provides you with integer id's I would recommend storing all of them to an int array and then using a random number for the index.

The code would look something like this:

int imageArr[] = new int[NUM_IMAGES]; 

imageArr[1] = R.drawable.photo;

//(load your array here with the resource ids)

int n = (int)Math.random()*NUM_IMAGES;

image.setImage(imageArr[n]);

在这里,我们有一个非常直接的实现,并绕过字符串concats发生的所有创建和破坏.