//1
[textview deleteBackward]
[textField deleteBackward];
傻傻的自己写删除，后来发现了这个方法
那么直接调用方法删除普通文字最后一个字符
//2
-(NSString)removeLastOneChar:(NSString)origin{
NSString* cutted;
if([origin length] > 0){
cutted = [origin substringToIndex:([origin length]-1)];// 去掉最后一个","
}else{
cutted = origin;
}
return cutted;
}
