iOS之常用的方法和技巧

判斷字符串是不是以中文開頭

- (BOOL)isChineseFirst:(NSString *)firstString { //是否以中文開頭(unicode中文編碼范圍是0x4e00~0x9fa5) int utfCode = 0; void *buffer = &utfCode; NSRange range = NSMakeRange(0, 1); //判斷是不是中文開頭的,buffer->獲取字符的字節(jié)數(shù)據(jù) maxLength->buffer的最大長度 usedLength->實際寫入的長度，不需要的話可以傳遞NULL encoding->字符編碼常數(shù)，不同編碼方式轉(zhuǎn)換后的字節(jié)長是不一樣的，這里我用了UTF16 Little-Endian，maxLength為2字節(jié)，如果使用Unicode，則需要4字節(jié) options->編碼轉(zhuǎn)換的選項，有兩個值，分別是NSStringEncodingConversionAllowLossy和NSStringEncodingConversionExternalRepresentation range->獲取的字符串中的字符范圍,這里設(shè)置的第一個字符 remainingRange->建議獲取的范圍，可以傳遞NULL BOOL isChinese = [firstString getBytes:buffer maxLength:2 usedLength:NULL encoding:NSUTF16LittleEndianStringEncoding options:NSStringEncodingConversionExternalRepresentation range:range remainingRange:NULL]; if (isChinese && (utfCode >= 0x4e00 && utfCode <= 0x9fa5)) return YES; else return NO; }

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鍵盤回收

- (void)setUpForDismissKeyboard { UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAnywhereToDismissKeyboard:)]; NSOperationQueue *operation = [NSOperationQueue mainQueue]; [[NSNotificationCenter defaultCenter] addObserverForName:UIKeyboardWillShowNotification object:nil queue:operation usingBlock:^(NSNotification * _Nonnull note) { [self.view addGestureRecognizer:tapGesture]; }]; [[NSNotificationCenter defaultCenter] addObserverForName:UIKeyboardWillHideNotification object:nil queue:operation usingBlock:^(NSNotification * _Nonnull note) { [self.view removeGestureRecognizer:tapGesture]; }]; }

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禁止側(cè)滑返回上一個界面

if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) { self.navigationController.interactivePopGestureRecognizer.enabled = NO; }

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隱藏導(dǎo)航欄最下面的黑線

- (void)hiddenNavLine { if ([self.navigationController.navigationBar respondsToSelector:@selector( setBackgroundImage:forBarMetrics:)]){ NSArray *list=self.navigationController.navigationBar.subviews; for (id obj in list) { if ([UIDevice currentDevice].systemVersion.floatValue >= 10.0) { UIView *view = (UIView*)obj; for (id obj2 in view.subviews) { if ([obj2 isKindOfClass:[UIImageView class]]) { UIImageView *image = (UIImageView*)obj2; image.hidden = YES; } } } } } }

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去除自帶的searchBar的背景View

- (void)removeSearchBarBackGroundView { for(int i = 0 ;i < _searchBar.subviews.count;i++){ UIView * backView = _searchBar.subviews[i]; if ([backView isKindOfClass:NSClassFromString(@"UISearchBarBackground")] == YES) { [backView removeFromSuperview]; [_searchBar setBackgroundColor:[UIColor clearColor]]; break; } else { NSArray * arr = _searchBar.subviews[i].subviews; for(int j = 0;j < arr.count; j++){ UIView * barView = arr[i]; if ([barView isKindOfClass:NSClassFromString(@"UISearchBarBackground")] == YES) { [barView removeFromSuperview]; [_searchBar setBackgroundColor:[UIColor clearColor]]; break; } } } } }

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標(biāo)簽欄的背景圖顯示錯亂問題解決辦法：

//將圖片如下設(shè)置 [[UIImage imageNamed:@"me@2x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]

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網(wǎng)絡(luò)請求設(shè)置超時請求（基于AFNetworking3.0封裝的GET，POST請求用方法）

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager]; [manager.requestSerializer willChangeValueForKey:@"timeoutInterval"]; manager.requestSerializer.timeoutInterval = 15.f; [manager.requestSerializer didChangeValueForKey:@"timeoutInterval"];

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實用的獲取圖片的方法，防止內(nèi)存溢出：

// 建議使用該方法： NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"圖片" ofType:@"png"]; UIImage *image = [[UIImage alloc] initWithContentsOfFile:imagePath]; // 不建議使用該方法： UIImage *image = [UIImage imageNamed:@"圖片.png"];

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iOS

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版權(quán)聲明：本文內(nèi)容由網(wǎng)絡(luò)用戶投稿，版權(quán)歸原作者所有，本站不擁有其著作權(quán)，亦不承擔(dān)相應(yīng)法律責(zé)任。如果您發(fā)現(xiàn)本站中有涉嫌抄襲或描述失實的內(nèi)容，請聯(lián)系我們jiasou666@gmail.com 處理，核實后本網(wǎng)站將在24小時內(nèi)刪除侵權(quán)內(nèi)容。