iOS NSString匹配字符串开头,NSString匹配字符串开头, hasPrefix,NSString hasPrefix,猿说编程,

AVFoundation转场溶解过渡效果,AVFoundation转场,AVFoundation溶解,AVFoundation过渡,AVFoundation合并,AVFoundation教程,

iOS NSString获取指定下标字符,NSString获取指定下标字符,NSString substringWithRange,NSString characterAtIndex,

iOS NSString判断字符串是否为空判,NSString字符串是否为空判,NSString空字符串,NSString isEqual,

iOS NSString获取字符串长度,NSString获取字符串长度,NSString lengthOfBytesUsingEncoding, NSString length,NSString计算中文长度,

iOS NSString 和 bool 相互转换 NSString *str1 = @'YES'; NSString *str2 = @'NO'; //ok NSLog(@'str1 = %d str2 = %d',[str1 boolValue],[str2 boolValue]); BOOL a = YES; BOOL b = NO; NSSt...

iOS NSString 与 float 相互转换 一.NSString 转 float NSString *stringFloat = @“120.5”; float fvalue = [stringFloat floatValue]; 二.float 转 NSString float fvalue = 100.5; NSString...

AVFoundation - 指定时间截取音视频 - 为了避免导出失败，解决方案是提取视频资源 AVURLAsset 音频轨道和视频轨道，重新构建 AVComposition ，然后在使用 AVAssetExportSession 导出; AVMutable...

iOS NSString 与 char 相互转换 一.NSString 转 char 1.stringWithFormat 2.stringWithUTF8String 3.stringWithCString 二.char 转 NSString 1.UTF8String 2.cStringUsingEncoding

iOS NSString 与 int 相互转换 - 一.NSString 转 int int ivalue = 100; NSString *string = [NSString stringWithFormat:@'%d',ivalue]; 二.int 转 NSString NSString *stringInt = @“120”; ...