ios - 如何使用 kmPerHour UnitType 处理MeasurementFormatter？

Question

我需要使用 Objective-C 上的 MeasurementFormatter 显示 km/h 值的整数。

有 sample 吗？

NSMeasurementFormatter *formatter = [[NSMeasurementFormatter alloc] init];
formatter.unitStyle = MKDistanceFormatterUnitStyleAbbreviated;

Answer 1

举个例子

    NSMeasurementFormatter *formatter = [[NSMeasurementFormatter alloc] init];
    formatter.unitStyle = NSFormattingUnitStyleMedium;
    formatter.locale = [NSLocale localeWithLocaleIdentifier:@"en_US"];

    // format 100 km/h

    formatter.unitOptions = NSMeasurementFormatterUnitOptionsProvidedUnit;
    NSUnitSpeed *speed = [NSUnitSpeed kilometersPerHour];
    NSString *speedString = [formatter stringFromMeasurement:[[NSMeasurement alloc] initWithDoubleValue:100.0 unit:speed]];

    NSLog(@"kilometers %@", speedString);

    // format 100 mph

    formatter.unitOptions = NSMeasurementFormatterUnitOptionsProvidedUnit;
    speed = [NSUnitSpeed milesPerHour];
    speedString = [formatter stringFromMeasurement:[[NSMeasurement alloc] initWithDoubleValue:100.0 unit:speed]];

    NSLog(@"miles %@", speedString);

    // convert 100 km/h to 62.137 mph for en_US locale

    formatter.unitOptions = NSMeasurementFormatterUnitOptionsNaturalScale;
    speed = [NSUnitSpeed kilometersPerHour];
    speedString = [formatter stringFromMeasurement:[[NSMeasurement alloc] initWithDoubleValue:100.0 unit:speed]];

    NSLog(@"miles to kilometers %@", speedString);