微信表情 ios（微信ios表情包）

最近项目需求，要实现一个类似微信的的表情输入，于是把微信的表情扒拉出来，实现了一把。可以从这里下载源码。看起来表情输入没有多少东西，不外乎就是用nstextattachment来实现图文混排，结果在实现的过程中遇到了很多小问题，接下来会一一介绍遇到过的坑。先上一张效果图：

微信表情 ios（微信ios表情包）

一、实现表情选择view(wkexpressionview)

具体的实现就不细说了，主要功能就是点击表情时，将对应表情的图片名称通知给delegate。

二、实现表情textview(wkexpressiontextview)

wkexpressiontextview继承自uitextview, 提供
- (void)setexpressionwithimagename:(nsstring *)imagename fontsize:(cgfloat)fontsize方法，用于根据图片插入表情。具体实现：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 //富文本 wkexpressiontextattachment *attachment = [[wkexpressiontextattachment alloc] initwithdata:nil oftype:nil]; uiimage *image = [uiimage imagenamed:imagename]; attachment.image = image; attachment.text = [wkexpressiontool getexpressionstringwithimagename:imagename]; attachment.bounds = cgrectmake(0, 0, fontsize, fontsize); nsattributedstring *insertattributestr = [nsattributedstring attributedstringwithattachment:attachment]; nsmutableattributedstring *resultattrstring = [[nsmutableattributedstring alloc] initwithattributedstring:self.attributedtext]; //在当前编辑位置插入字符串 [resultattrstring insertattributedstring:insertattributestr atindex:self.selectedrange.location]; nsrange temprange = self.selectedrange; self.attributedtext = resultattrstring; self.selectedrange = nsmakerange(temprange.location + 1, 0); [self.textstorage addattributes:@{nsfontattributename : [uifont systemfontofsize:_defaultfontsize]} range:nsmakerange(0, self.attributedtext.length)]; [self scrollrangetovisible:self.selectedrange]; [self textchanged];

其中wkexpressiontextattachment继承自nstextattachment, 并新增text字段，为了保存表情对应的文本，用于复制粘贴操作。

1 2 3 @interface wkexpressiontextattachment : nstextattachment @property (nonatomic, copy) nsstring *text; @end

wkexpressiontool的提供将普通字符串转换为富文本的方法，主要用于复制时生成表情。

主要方法

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 + (nsattributedstring *)generateattributestringwithoriginalstring:(nsstring *)originalstring fontsize:(cgfloat)fontsize { nserror *error = null; nsmutableattributedstring *resultattrstring = [[nsmutableattributedstring alloc] initwithstring:originalstring]; nsregularexpression *regex = [nsregularexpression regularexpressionwithpattern:@"\\[[a-za-z0-9\u4e00-\u9fa5]{1,}\\]" options:nsregularexpressionallowcommentsandwhitespace error:&error]; nsarray *results = [regex matchesinstring:originalstring options:nsmatchingreportcompletion range:nsmakerange(0, originalstring.length)]; if (results) { for (nstextcheckingresult *result in results.reverseobjectenumerator) { nsrange resultrange = [result rangeatindex:0]; nsstring *stringresult = [originalstring substringwithrange:resultrange]; nslog(@"%s %@\n", __function__, stringresult); nsattributedstring *expressionattrstring = [self getattributestringwithexpressionstring:stringresult fontsize:fontsize]; [resultattrstring replacecharactersinrange:resultrange withattributedstring:expressionattrstring]; } } return resultattrstring; } /** * 通过表情生成富文本 * * @param expressionstring 表情名 * @param fontsize 对应字体大小 * * @return 富文本 */ + (nsattributedstring *)getattributestringwithexpressionstring:(nsstring *)expressionstring fontsize:(cgfloat)fontsize { nsstring *imagename = [self getexpressionstringwithimagename:expressionstring]; wkexpressiontextattachment *attachment = [[wkexpressiontextattachment alloc] initwithdata:nil oftype:nil]; uiimage *image = [uiimage imagenamed:imagename]; attachment.image = image; attachment.text = [wkexpressiontool getexpressionstringwithimagename:imagename]; attachment.bounds = cgrectmake(0, 0, fontsize, fontsize); nsattributedstring *appendattributestr = [nsattributedstring attributedstringwithattachment:attachment]; return appendattributestr; }

至此，基本功能实现完成。接下来说说遇到的小问题

编辑是应该对应selectedrange

复制粘贴操作需要重新实现

textview在插入nstextattachment后，会默认把font的size修改为12，需要记录默认的size

对应selectedrange操作

具体的操作查看源码

重新实现copy、cut方法

进行复制、粘贴操作会发现，不能对图片进行复制，所以需要自己重写copy、cut方法

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 - (void)copy:(id)sender { nsattributedstring *selectedstring = [self.attributedtext attributedsubstringfromrange:self.selectedrange]; nsstring *copystring = [self parseattributetexttonormalstring:selectedstring]; uipasteboard *pboard = [uipasteboard generalpasteboard]; if (copystring.length != 0) { pboard.string = copystring; } } - (void)cut:(id)sender { [self copy:sender]; nsmutableattributedstring *originalstring = [[nsmutableattributedstring alloc] initwithattributedstring:self.attributedtext]; [originalstring deletecharactersinrange:self.selectedrange]; self.attributedtext = originalstring; nslog(@"--%@", nsstringfromrange(self.selectedrange)); [self textchanged]; }

记录默认font的size

利用实例变量defaultfontsize，在wkexpressiontextview实例化时记录self.font.pointsize，以后需要取font的size时，直接取defaultfontsize

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 @interface wkexpressiontextview : uitextview @property (nonatomic, assign) cgfloat defaultfontsize; @end @implementation wkexpressiontextview { cgfloat _defaultfontsize; } - (void)awakefromnib { [self setup]; } - (instancetype)initwithframe:(cgrect)frame { self = [super initwithframe:frame]; if (self) { [self setup]; } return self; } - (void)setup { [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(textchange:) name:uitextviewtextdidchangenotification object:self]; _defaultfontsize = self.font.pointsize; self.delegate = self; }