字符串的处理

iOS字符串处理_替换(去掉空格换行)、截取

以下代码主要实现了：1、截取"@@"前的字符串；  2、去掉字符串中的"##"；  3、去掉字符串中的空格和换行。

希望相互学习相互指正。

-----ViewController.m内容如下:------

#import "ViewController.h"

#import "HandleString.h"

@interface ViewController ()

{

NSString *_str;

NSString *_tempStr;

UILabel *_label;

}

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

#pragma -----1.截取@@前面的内容 2.去掉## 3.去掉空格换行

_str = @"静夜思##\n床前   明月光\n##疑是   ##地上霜\n举头@@   望明月\n低头   思故乡";

_tempStr = _str;

[self createSubview];

}

- (void)createSubview{

_label = [[UILabel alloc]init];

CGRect temp = self.view.frame;

temp.origin.x += 20;

temp.origin.y += 80;

temp.size.width -= 40;

temp.size.height = 150;

_label.frame = temp;

_label.textAlignment = NSTextAlignmentCenter;

_label.lineBreakMode = NSLineBreakByWordWrapping;

_label.numberOfLines = 0;

_label.text = _str;

_label.textColor = [UIColor greenColor];

_label.backgroundColor = [[UIColor blueColor]colorWithAlphaComponent:0.3];

[self.view addSubview:_label];

for (NSInteger i = 0; i<4; i++) {

UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];

btn.frame = CGRectMake(0, CGRectGetMaxY(_label.frame)+50*(i+1), 150, 40);

CGRect a = btn.frame;

a.origin.x = self.view.center.x - a.size.width/2;

btn.frame = a;

btn.backgroundColor = [UIColor cyanColor];

NSArray *arr = @[@"截取@@前面的内容",@"去掉##",@"去掉空格换行",@"还原"];

[btn setTitle:arr[i] forState:UIControlStateNormal];

btn.tag = 10 + i;//tag分别为10，11，12，13

[btn addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:btn];

}

}

- (void)click:(UIButton *)button{

NSInteger x = button.tag;

switch (x) {

case 10:

_tempStr = [HandleString handleString:_tempStr interceptFrom:nil to:@"@"];

break;

case 11:

_tempStr = [HandleString handleString:_tempStr replace:@"##" with:@" "];

break;

case 12:

_tempStr = [HandleString delSpaceAndNewline:_tempStr];

break;

case 13:

_tempStr = _str;

break;

default:

break;

}

_label.text = _tempStr;

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

------HandleString.h的内容如下：---------

#import

@interface HandleString : NSObject

//用str2替换str1

+ (NSString *)handleString:(NSString *)string replace:(NSString *)str1 with:(NSString *)str2;

//从str1(包括)，截取字符串到str2(不包括)

+ (NSString *)handleString:(NSString *)string interceptFrom:(NSString *)str1 to:(NSString *)str2;

//去掉字符串中的空格、换行

+ (NSString *)delSpaceAndNewline:(NSString *)string;

@end

------HandleString.m的内容如下：---------

#import "HandleString.h"

@implementation HandleString

+ (NSString *)delSpaceAndNewline:(NSString *)string;{

NSMutableString *mutStr = [NSMutableString stringWithString:string];

NSRange range = {0,mutStr.length};

[mutStr replaceOccurrencesOfString:@" " withString:@"" options:NSLiteralSearch range:range];

NSRange range2 = {0,mutStr.length};

[mutStr replaceOccurrencesOfString:@"\n" withString:@"" options:NSLiteralSearch range:range2];

return mutStr;

//    string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; //去除掉首尾的空白字符和换行字符

//    string = [string stringByReplacingOccurrencesOfString:@" " withString:@""];

//    string = [string stringByReplacingOccurrencesOfString:@"\n" withString:@""];

//    return string;

}

#pragma -----如果字符串中有str1,用str2替换掉

+ (NSString *)handleString:(NSString *)string replace:(NSString *)str1 with:(NSString *)str2;{

if (str2 == nil) {

str2 = @"";

}

//    //方式一

//    NSMutableString *tempStr = [NSMutableString stringWithString:string];

//    NSRange range = {0,tempStr.length};

//    [tempStr replaceOccurrencesOfString:str1 withString:str2 options:NSLiteralSearch range:range];

//    return tempStr;

//    //方式二

//    string = [string stringByReplacingOccurrencesOfString:str1 withString:str2];

//    return string;

//方式三

NSArray *array = [string componentsSeparatedByString:str1];

NSInteger count = [array count] - 1;

NSMutableString *tempStr = [NSMutableString stringWithString:string];

for (NSInteger i = 0; i

NSRange range = [tempStr rangeOfString:str1];

NSInteger location = range.location;

NSInteger length = range.length;

if (location != NSNotFound) {

[tempStr replaceCharactersInRange:NSMakeRange(location, length) withString:str2];

}

}

return tempStr;

}

#pragma ------从字符串str1,截取到str2

+ (NSString *)handleString:(NSString *)string interceptFrom:(NSString *)str1 to:(NSString *)str2;{

if (str1 == nil) {

str1 = @"";

}

if (str2 == nil) {

str2 = @"";

}

NSRange range1 = [string rangeOfString:str1];

NSInteger location1 = range1.location;

if (location1 != NSNotFound) {

string = [string substringFromIndex:location1];

}

NSRange range2 = [string rangeOfString:str2];

NSInteger location2 = range2.location;

if (location2 != NSNotFound) {

string = [string substringToIndex:location2];

}

return string;

}

@end

END