我该如何检查，看看是否在Android中的资源存在 [英] How do I check to see if a resource exists in Android

问题描述

有一个内置的方法来检查，看是否有资源存在还是我留下做一些这样的：

Is there a built in way to check to see if a resource exists or am I left doing something like the following:

boolean result;
try {
    int test = mContext.getResources().getIdentifier("my_resource_name", "drawable", mContext.getPackageName());
    if (test != 0) 
        result = true;
}
finally {
    result = false;
}

另外，我甚至需要在尝试，终于阻止？

推荐答案

据javadoc的，你不需要尝试捕捉： <一href="http://developer.android.com/reference/android/content/res/Resources.html#getIdentifier%28java.lang.String,%20java.lang.String,%20java.lang.String%29" rel="nofollow">http://developer.android.com/reference/android/content/res/Resources.html#getIdentifier%28java.lang.String,%20java.lang.String,%20java.lang.String%29

According to the javadoc you don't need the try catch: http://developer.android.com/reference/android/content/res/Resources.html#getIdentifier%28java.lang.String,%20java.lang.String,%20java.lang.String%29

如果则getIdentifier（）返回零，这意味着没有这样的资源存在。
也为0 - 是非法的资源ID

if getIdentifier() returns zero, it means that no such resource exists.
Also 0 - is an illegal resource id.

所以，你的结果布尔变量等效于（测试！= 0）。

So your result boolean variable is equivalent to (test != 0).

反正你的try /总算是不好的，因为它的作用是设定的结果变量设置为false，即使异常是从尝试的身体抛出： mContext.get ..... ，然后它只是重新抛出走出终于子句后例外。而我想这是不是你想要做的情况下，异常的事情。

Anyway your try/finally is bad, because all it does it set the result variable to false even if exception is thrown from the body of try: mContext.get..... and then it just "rethrows" the exception after getting out of finally clause. And I suppose that is not what you want to do in case of exception.

这篇关于我该如何检查，看看是否在Android中的资源存在的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！