Android Studio如何将具有ID的字符串转换为Int？

Question

Is there any way to convert string with id (for example: String id = "R.id.id" ) to int?

I have tried this:

String st = "R.id.id";
int id = Integer.parseInt(st);

But it didn't work.

Thanks for help!

Answer 1

What you are asking is completely wrong.

"R.id.id" is a String that can't be converted in a int.

It will always throw a NumberFormatException .

Check the javadoc :

Parses the string argument as a signed decimal integer. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign '-' ('\-') to indicate a negative value or an ASCII plus sign '+' ('\+') to indicate a positive value. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseInt(java.lang.String, int) method.

If the resource used in your strings.xml with the same id is a integer, you have to use somenthing different:

<resources>
    <string name="mystring">12</string>
</resources>

Use this code to retrieve a string:

String string = getString(R.string.mystring);

try{
   int number = Integer.parseInt(string);
} catch (NumberFormatException nfe){
  //.....
}

Answer 2

String that consists of other than numeric values can not be converted to int or into any of the numeric data types. However if a string hold numeric value then you can convert it into int or other numeric data types. And the reason for it is every programming language has its syntax defined, if you want to assign value through character You can do as

int variableName = 'a';
or
int variableName = 'b';

etc. this is spacial numeric assigning in java 'a' equals 97 & 'b' equals 98 .

Or if a string hold numeric value you can convert it as

<resources>
    <string name="stringVal">500</string>
</resources>

get like this

String string = getString(R.string.stringVal);


   int anyName= Integer.parseInt(string);