NSString问题

Question

NSRange rangetxt={0,(index-1)};
NSString *tempStr= textBox.text;
NSString *tempTextBox=[tempStr substringWithRange:rangetxt];

Hi Everyone,

I want to know why my pasted code isn't working properly, when the compiler passes substringWithRange It hung up and do not assign any value to tempTextBox , Secondly I've tried the NSString function substringToIndex as well yet its not working too, My objective is to skip the last character while copying tempStr to tempTextBox .

Regards MGD

Answer 1

您应该使用NSMakeRange(loc, len)创建一个NSRange对象，而不要使用{} 。

Answer 2

I had test this code and it works:

NSString *strTest = @"Word";
NSRange range = {0, 3};
NSString *strTemp = [strTest substringWithRange: range];

The result: strTemp = "Wor"

So the problem is something else: index is not proper or textBox.text is maybe empty.

Put the breakpoint on your substringWithRange: line and look at the values of index and tempStr before problem appears.

Answer 3

You don't show the code that's initialising index . My guess is it's out of range. Note that substringWithRange raises an NSRangeException if any part of the range lies beyond the end of the receiver.

Try this:

NSString *tempStr = textBox.text;
NSRange rangetxt;
if ([tempStr length] > 0)
    rangetxt = NSMakeRange(0, [tempStr length] - 1);
else
    rangetxt = NSMakeRange(0, 0); 
NSString *tempTextBox = [tempStr substringWithRange:rangetxt];

Answer 4

I think i got my problem solved, During the debug when i pass through these line my gdb says "Timed out fetching data. Variable display may be inaccurate" so i found the solution just placed my break point after the initialization of the NSString objects

Thanks for Help Everyone

MGD