版本記錄
| 版本號 | 時間 |
|---|---|
| V1.0 | 2018.03.20 |
前言
iOS圈內(nèi)有幾個人大家基本都知道，比如說王巍、唐巧，還有YYKit框架的作者現(xiàn)任職于滴滴的郭曜源 - ibireme等。這里有一篇唐巧對他的專訪，還有他的 GitHub - Yaoyuan 和 博客，這里貼出來框架YYKit 框架。接下來幾篇我們就一起來看一下這個框架。感興趣的可以看上面寫的幾篇。
1. YYKit源碼探究（一） —— 基本概覽
2. YYKit源碼探究（二） —— NSString分類之Hash（一）
3. YYKit源碼探究（三） —— NSString分類之Encode and decode（二）
4. YYKit源碼探究（四） —— NSString分類之Drawing（三）
5. YYKit源碼探究（五） —— NSString分類之Regular Expression（四）
6. YYKit源碼探究（六） —— NSString分類之NSNumber Compatible（五）
回顧
上一篇我們分析了NSString分類NSString+YYAdd的NSNumber Compatible部分，這一篇我們就看一下Utilities部分。
API 接口
下面我們看一下API接口。
/**
Returns a new UUID NSString
e.g. "D1178E50-2A4D-4F1F-9BD3-F6AAB00E06B1"
*/
+ (NSString *)stringWithUUID;
/**
Returns a string containing the characters in a given UTF32Char.
@param char32 A UTF-32 character.
@return A new string, or nil if the character is invalid.
*/
+ (nullable NSString *)stringWithUTF32Char:(UTF32Char)char32;
/**
Returns a string containing the characters in a given UTF32Char array.
@param char32 An array of UTF-32 character.
@param length The character count in array.
@return A new string, or nil if an error occurs.
*/
+ (nullable NSString *)stringWithUTF32Chars:(const UTF32Char *)char32 length:(NSUInteger)length;
/**
Enumerates the unicode characters (UTF-32) in the specified range of the string.
@param range The range within the string to enumerate substrings.
@param block The block executed for the enumeration. The block takes four arguments:
char32: The unicode character.
range: The range in receiver. If the range.length is 1, the character is in BMP;
otherwise (range.length is 2) the character is in none-BMP Plane and stored
by a surrogate pair in the receiver.
stop: A reference to a Boolean value that the block can use to stop the enumeration
by setting *stop = YES; it should not touch *stop otherwise.
*/
- (void)enumerateUTF32CharInRange:(NSRange)range usingBlock:(void (^)(UTF32Char char32, NSRange range, BOOL *stop))block;
/**
Trim blank characters (space and newline) in head and tail.
@return the trimmed string.
*/
- (NSString *)stringByTrim;
/**
Add scale modifier to the file name (without path extension),
From @"name" to @"name@2x".
e.g.
<table>
<tr><th>Before </th><th>After(scale:2)</th></tr>
<tr><td>"icon" </td><td>"icon@2x" </td></tr>
<tr><td>"icon " </td><td>"icon @2x" </td></tr>
<tr><td>"icon.top" </td><td>"icon.top@2x" </td></tr>
<tr><td>"/p/name" </td><td>"/p/name@2x" </td></tr>
<tr><td>"/path/" </td><td>"/path/" </td></tr>
</table>
@param scale Resource scale.
@return String by add scale modifier, or just return if it's not end with file name.
*/
- (NSString *)stringByAppendingNameScale:(CGFloat)scale;
/**
Add scale modifier to the file path (with path extension),
From @"name.png" to @"name@2x.png".
e.g.
<table>
<tr><th>Before </th><th>After(scale:2)</th></tr>
<tr><td>"icon.png" </td><td>"icon@2x.png" </td></tr>
<tr><td>"icon..png"</td><td>"icon.@2x.png"</td></tr>
<tr><td>"icon" </td><td>"icon@2x" </td></tr>
<tr><td>"icon " </td><td>"icon @2x" </td></tr>
<tr><td>"icon." </td><td>"icon.@2x" </td></tr>
<tr><td>"/p/name" </td><td>"/p/name@2x" </td></tr>
<tr><td>"/path/" </td><td>"/path/" </td></tr>
</table>
@param scale Resource scale.
@return String by add scale modifier, or just return if it's not end with file name.
*/
- (NSString *)stringByAppendingPathScale:(CGFloat)scale;
/**
Return the path scale.
e.g.
<table>
<tr><th>Path </th><th>Scale </th></tr>
<tr><td>"icon.png" </td><td>1 </td></tr>
<tr><td>"icon@2x.png" </td><td>2 </td></tr>
<tr><td>"icon@2.5x.png" </td><td>2.5 </td></tr>
<tr><td>"icon@2x" </td><td>1 </td></tr>
<tr><td>"icon@2x..png" </td><td>1 </td></tr>
<tr><td>"icon@2x.png/" </td><td>1 </td></tr>
</table>
*/
- (CGFloat)pathScale;
/**
nil, @"", @" ", @"\n" will Returns NO; otherwise Returns YES.
*/
- (BOOL)isNotBlank;
/**
Returns YES if the target string is contained within the receiver.
@param string A string to test the the receiver.
@discussion Apple has implemented this method in iOS8.
*/
- (BOOL)containsString:(NSString *)string;
/**
Returns YES if the target CharacterSet is contained within the receiver.
@param set A character set to test the the receiver.
*/
- (BOOL)containsCharacterSet:(NSCharacterSet *)set;
/**
Try to parse this string and returns an `NSNumber`.
@return Returns an `NSNumber` if parse succeed, or nil if an error occurs.
*/
- (nullable NSNumber *)numberValue;
/**
Returns an NSData using UTF-8 encoding.
*/
- (nullable NSData *)dataValue;
/**
Returns NSMakeRange(0, self.length).
*/
- (NSRange)rangeOfAll;
/**
Returns an NSDictionary/NSArray which is decoded from receiver.
Returns nil if an error occurs.
e.g. NSString: @"{"name":"a","count":2}" => NSDictionary: @[@"name":@"a",@"count":@2]
*/
- (nullable id)jsonValueDecoded;
/**
Create a string from the file in main bundle (similar to [UIImage imageNamed:]).
@param name The file name (in main bundle).
@return A new string create from the file in UTF-8 character encoding.
*/
+ (nullable NSString *)stringNamed:(NSString *)name;
1. + (NSString *)stringWithUUID;
該方法返回的是UUID字符串。
示例調(diào)用
NSString *resultStr = [NSString stringWithUUID];
NSLog(@"UUID為 = %@", resultStr);
下面看一下輸出結(jié)果
2018-03-19 14:28:47.932947+0800 JJWebImage[29178:4163246] UUID為 = 03367F43-93A0-41AC-A2AC-650A31F0A40A
方法實現(xiàn)
+ (NSString *)stringWithUUID {
CFUUIDRef uuid = CFUUIDCreate(NULL);
CFStringRef string = CFUUIDCreateString(NULL, uuid);
CFRelease(uuid);
return (__bridge_transfer NSString *)string;
}
2. + (nullable NSString *)stringWithUTF32Char:(UTF32Char)char32;
該方法的作用就是將給定的UTF32Char類型的字符轉(zhuǎn)化為一個NSString類型的字符串，如果這個字符是無效的，那么轉(zhuǎn)化的字符串為nil。
示例調(diào)用
下面看一個示例。
UTF32Char number = 97;
NSString *resultStr = [NSString stringWithUTF32Char:number];
NSLog(@"resultStr = %@", resultStr);
下面看一下輸出結(jié)果
2018-03-19 14:35:36.296366+0800 JJWebImage[29190:4166179] resultStr = a
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
+ (NSString *)stringWithUTF32Char:(UTF32Char)char32 {
char32 = NSSwapHostIntToLittle(char32);
return [[NSString alloc] initWithBytes:&char32 length:4 encoding:NSUTF32LittleEndianStringEncoding];
}
上面方法的實現(xiàn)中調(diào)用的兩個方法均為系統(tǒng)內(nèi)部的方法。
3. + (nullable NSString *)stringWithUTF32Chars:(const UTF32Char *)char32 length:(NSUInteger)length;
該方法的作用就是根據(jù)給定的 UTF-32字符組和長度，返回一個字符串。
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
+ (NSString *)stringWithUTF32Chars:(const UTF32Char *)char32 length:(NSUInteger)length {
return [[NSString alloc] initWithBytes:(const void *)char32
length:length * 4
encoding:NSUTF32LittleEndianStringEncoding];
}
4. - (void)enumerateUTF32CharInRange:(NSRange)range usingBlock:(void (^)(UTF32Char char32, NSRange range, BOOL *stop))block;
枚舉字符串指定范圍內(nèi)的Unicode字符（UTF-32），這里需要說明下幾個參數(shù)：
-
range：字符串在range范圍內(nèi)遍歷子字符串。 -
block：執(zhí)行遍歷的塊。-
char32： unicode字符 -
range：這個是接受者，如果range.length == 1，字符是BMP；否則（range.length == 2），該字符在非BMP平面中，并由代理對存儲在接收器中。 -
stop： 一個布爾值的引用，塊可以通過設(shè)置* stop = YES來停止遍歷。
-
下面看一下該方法的實現(xiàn)
- (void)enumerateUTF32CharInRange:(NSRange)range usingBlock:(void (^)(UTF32Char char32, NSRange range, BOOL *stop))block {
NSString *str = self;
if (range.location != 0 || range.length != self.length) {
str = [self substringWithRange:range];
}
NSUInteger len = [str lengthOfBytesUsingEncoding:NSUTF32StringEncoding] / 4;
UTF32Char *char32 = (UTF32Char *)[str cStringUsingEncoding:NSUTF32LittleEndianStringEncoding];
if (len == 0 || char32 == NULL) return;
NSUInteger location = 0;
BOOL stop = NO;
NSRange subRange;
UTF32Char oneChar;
for (NSUInteger i = 0; i < len; i++) {
oneChar = char32[i];
subRange = NSMakeRange(location, oneChar > 0xFFFF ? 2 : 1);
block(oneChar, subRange, &stop);
if (stop) return;
location += subRange.length;
}
}
5. - (NSString *)stringByTrim;
該方法的作用就是修剪頭部和尾部的空白字符（空格和換行符）。
示例調(diào)用
下面看一個示例。
NSString *str = @" aaaa ";
NSLog(@"str = %@, length = %ld", str, str.length);
NSString *resultStr = [str stringByTrim];
NSLog(@"resultStr = %@, length = %ld", resultStr, resultStr.length);
下面看一下輸出結(jié)果
2018-03-19 15:25:58.879383+0800 JJWebImage[29207:4179554] str = aaaa , length = 6
2018-03-19 15:25:58.879752+0800 JJWebImage[29207:4179554] resultStr = aaaa, length = 4
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (NSString *)stringByTrim {
NSCharacterSet *set = [NSCharacterSet whitespaceAndNewlineCharacterSet];
return [self stringByTrimmingCharactersInSet:set];
}
6. - (NSString *)stringByAppendingNameScale:(CGFloat)scale;
下面我們看一下這個方法
/**
Add scale modifier to the file name (without path extension),
From @"name" to @"name@2x".
e.g.
<table>
<tr><th>Before </th><th>After(scale:2)</th></tr>
<tr><td>"icon" </td><td>"icon@2x" </td></tr>
<tr><td>"icon " </td><td>"icon @2x" </td></tr>
<tr><td>"icon.top" </td><td>"icon.top@2x" </td></tr>
<tr><td>"/p/name" </td><td>"/p/name@2x" </td></tr>
<tr><td>"/path/" </td><td>"/path/" </td></tr>
</table>
@param scale Resource scale.
@return String by add scale modifier, or just return if it's not end with file name.
*/
- (NSString *)stringByAppendingNameScale:(CGFloat)scale;
其實，就是實現(xiàn)類似@"name" 到 @"name@2x"這樣的功能。
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (NSString *)stringByAppendingNameScale:(CGFloat)scale {
if (fabs(scale - 1) <= __FLT_EPSILON__ || self.length == 0 || [self hasSuffix:@"/"]) return self.copy;
return [self stringByAppendingFormat:@"@%@x", @(scale)];
}
7. - (NSString *)stringByAppendingPathScale:(CGFloat)scale;
看一下這個方法
/**
Add scale modifier to the file path (with path extension),
From @"name.png" to @"name@2x.png".
e.g.
<table>
<tr><th>Before </th><th>After(scale:2)</th></tr>
<tr><td>"icon.png" </td><td>"icon@2x.png" </td></tr>
<tr><td>"icon..png"</td><td>"icon.@2x.png"</td></tr>
<tr><td>"icon" </td><td>"icon@2x" </td></tr>
<tr><td>"icon " </td><td>"icon @2x" </td></tr>
<tr><td>"icon." </td><td>"icon.@2x" </td></tr>
<tr><td>"/p/name" </td><td>"/p/name@2x" </td></tr>
<tr><td>"/path/" </td><td>"/path/" </td></tr>
</table>
@param scale Resource scale.
@return String by add scale modifier, or just return if it's not end with file name.
*/
- (NSString *)stringByAppendingPathScale:(CGFloat)scale;
其實就是實現(xiàn)從@"name.png" 到 @"name@2x.png"這樣的類似轉(zhuǎn)化。
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (NSString *)stringByAppendingPathScale:(CGFloat)scale {
if (fabs(scale - 1) <= __FLT_EPSILON__ || self.length == 0 || [self hasSuffix:@"/"]) return self.copy;
NSString *ext = self.pathExtension;
NSRange extRange = NSMakeRange(self.length - ext.length, 0);
if (ext.length > 0) extRange.location -= 1;
NSString *scaleStr = [NSString stringWithFormat:@"@%@x", @(scale)];
return [self stringByReplacingCharactersInRange:extRange withString:scaleStr];
}
8. - (CGFloat)pathScale;
下面我們看一下該方法
/**
Return the path scale.
e.g.
<table>
<tr><th>Path </th><th>Scale </th></tr>
<tr><td>"icon.png" </td><td>1 </td></tr>
<tr><td>"icon@2x.png" </td><td>2 </td></tr>
<tr><td>"icon@2.5x.png" </td><td>2.5 </td></tr>
<tr><td>"icon@2x" </td><td>1 </td></tr>
<tr><td>"icon@2x..png" </td><td>1 </td></tr>
<tr><td>"icon@2x.png/" </td><td>1 </td></tr>
</table>
*/
- (CGFloat)pathScale;
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (CGFloat)pathScale {
if (self.length == 0 || [self hasSuffix:@"/"]) return 1;
NSString *name = self.stringByDeletingPathExtension;
__block CGFloat scale = 1;
[name enumerateRegexMatches:@"@[0-9]+\\.?[0-9]*x$" options:NSRegularExpressionAnchorsMatchLines usingBlock: ^(NSString *match, NSRange matchRange, BOOL *stop) {
scale = [match substringWithRange:NSMakeRange(1, match.length - 2)].doubleValue;
}];
return scale;
}
9. - (BOOL)isNotBlank;
該方法的作用就是用來判斷是否是空白。nil, @"", @" ", @"\n"會返回NO，其他返回YES。
示例調(diào)用
下面看一個示例。
NSString *str = @" ";
BOOL isNotBlank = [str isNotBlank];
NSLog(@"isNotBlank = %d", isNotBlank);
NSString *str1 = @"aaaa";
BOOL isNotBlank1 = [str1 isNotBlank];
NSLog(@"isNotBlank1 = %d", isNotBlank1);
下面看一下輸出結(jié)果
2018-03-19 15:44:04.690104+0800 JJWebImage[29214:4184283] isNotBlank = 0
2018-03-19 15:44:04.690198+0800 JJWebImage[29214:4184283] isNotBlank1 = 1
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (BOOL)isNotBlank {
NSCharacterSet *blank = [NSCharacterSet whitespaceAndNewlineCharacterSet];
for (NSInteger i = 0; i < self.length; ++i) {
unichar c = [self characterAtIndex:i];
if (![blank characterIsMember:c]) {
return YES;
}
}
return NO;
}
10. - (BOOL)containsString:(NSString *)string;
這個方法很好理解，就是判斷一個字符串是否包含另外一個字符串。
示例調(diào)用
下面看一個示例。
NSString *str = @"abcde";
BOOL isContain = [str containsString:@"a"];
NSLog(@"isContain = %d", isContain);
NSString *str1 = @"abcde";
BOOL isContain1 = [str1 containsString:@"f"];
NSLog(@"isContain = %d", isContain1);
下面我們看一下輸出結(jié)果
2018-03-19 16:16:17.588977+0800 JJWebImage[29217:4192114] isContain = 1
2018-03-19 16:16:17.589063+0800 JJWebImage[29217:4192114] isContain = 0
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (BOOL)containsString:(NSString *)string {
if (string == nil) return NO;
return [self rangeOfString:string].location != NSNotFound;
}
11. - (BOOL)containsCharacterSet:(NSCharacterSet *)set;
這個方法的作用就是字符串是否包含某個字符。
示例調(diào)用
下面看一個示例。
NSString *str = @"abc de";
BOOL isContain = [str containsCharacterSet:[NSCharacterSet whitespaceCharacterSet]];
NSLog(@"isContain = %d", isContain);
NSString *str1 = @"abcde";
BOOL isContain1 = [str1 containsCharacterSet:[NSCharacterSet whitespaceCharacterSet]];
NSLog(@"isContain1 = %d", isContain1);
下面看一下輸出結(jié)果
2018-03-19 16:22:55.638426+0800 JJWebImage[29222:4194182] isContain = 1
2018-03-19 16:22:55.638514+0800 JJWebImage[29222:4194182] isContain1 = 0
方法實現(xiàn)
下面看一下該方法的實現(xiàn)
- (BOOL)containsCharacterSet:(NSCharacterSet *)set {
if (set == nil) return NO;
return [self rangeOfCharacterFromSet:set].location != NSNotFound;
}
12. - (nullable NSNumber *)numberValue;
這個方法很簡單就不舉例了，就是將字符串轉(zhuǎn)化為NSNumber數(shù)據(jù)類型，如果不能轉(zhuǎn)換，就返回nil。
下面看一下方法實現(xiàn)
- (NSNumber *)numberValue {
return [NSNumber numberWithString:self];
}
13. - (nullable NSData *)dataValue;
這個方法很簡單就不舉例了，就是將字符串轉(zhuǎn)化為NSData數(shù)據(jù)類型，使用的是UTF - 8編碼。
下面看一下方法實現(xiàn)
- (NSData *)dataValue {
return [self dataUsingEncoding:NSUTF8StringEncoding];
}
14. - (NSRange)rangeOfAll;
這個方法很簡單就不舉例了，就是將返回字符串的range - NSMakeRange(0, self.length)。
下面我們看一下方法的實現(xiàn)過程。
- (NSRange)rangeOfAll {
return NSMakeRange(0, self.length);
}
15. - (nullable id)jsonValueDecoded;
該方法的作用就是將指定的Json字符串轉(zhuǎn)化為字典或者數(shù)組。
方法實現(xiàn)
下面看一下該方法的實現(xiàn)。
- (id)jsonValueDecoded {
return [[self dataValue] jsonValueDecoded];
}
下面就是調(diào)用NSData分類的這個方法了。
- (id)jsonValueDecoded {
NSError *error = nil;
id value = [NSJSONSerialization JSONObjectWithData:self options:kNilOptions error:&error];
if (error) {
NSLog(@"jsonValueDecoded error:%@", error);
}
return value;
}
16. + (nullable NSString *)stringNamed:(NSString *)name;
該方法的作用就是從main bundle文件中創(chuàng)建字符串，類似于[UIImage imageNamed:]。返回值為文件中UTF - 8編碼的字符串。
方法實現(xiàn)
下面看一下該方法的實現(xiàn)。
+ (NSString *)stringNamed:(NSString *)name {
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@""];
NSString *str = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:NULL];
if (!str) {
path = [[NSBundle mainBundle] pathForResource:name ofType:@"txt"];
str = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:NULL];
}
return str;
}
后記
本篇我們分析了Utilities部分的功能，主要就是涉及到字符串處理的一些小的工具，比如獲取UUID字符串等，喜歡的給個贊~~~
