Question

我有以下CorePlot（v1.2）代码，该代码基于http://www.raywenderlich.com/13271/how-to-draw-graphs-with-core-plot-part-2的教程，但扩展了一些。使用大约30个数据点，在iPhone 4S上渲染图形大约需要3秒钟。图表确实正确加载，它只是很慢。无论如何都要提高性能？

以下是代码的NSLog输出：

2013-05-30 17:41:20.386 myApp[2796:907] A
2013-05-30 17:41:20.387 myApp[2796:907] B
2013-05-30 17:41:20.388 myApp[2796:907] C
2013-05-30 17:41:20.389 myApp[2796:907] D
2013-05-30 17:41:21.158 myApp[2796:907] E
2013-05-30 17:41:21.160 myApp[2796:907] F
2013-05-30 17:41:22.594 myApp[2796:907] G

NB代码完成运行后，在渲染图形之前还有大约0.5秒的延迟。

代码：

-(void)configureAxes {

    NSLog(@"A");
    // 1 - Create styles
    CPTMutableTextStyle *axisTitleStyle = [CPTMutableTextStyle textStyle];
    axisTitleStyle.color = [CPTColor whiteColor];
    axisTitleStyle.fontName = @"Helvetica-Bold";
    axisTitleStyle.fontSize = 12.0f;
    CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
    axisLineStyle.lineWidth = 2.0f;
    axisLineStyle.lineColor = [CPTColor whiteColor];
    CPTMutableTextStyle *axisTextStyle = [[CPTMutableTextStyle alloc] init];
    axisTextStyle.color = [CPTColor whiteColor];
    axisTextStyle.fontName = @"Helvetica-Bold";
    axisTextStyle.fontSize = 11.0f;
    CPTMutableLineStyle *tickLineStyle = [CPTMutableLineStyle lineStyle];
    tickLineStyle.lineColor = [CPTColor whiteColor];
    tickLineStyle.lineWidth = 2.0f;
    NSLog(@"B");
    // 2 - Get axis set
    CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self.hostView.hostedGraph.axisSet;

    // 3 - Configure x-axis
    CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
    lineStyle.lineColor = [CPTColor whiteColor];
    lineStyle.lineWidth = 2.0f;

    CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
    textStyle.fontName = @"Helvetica";
    textStyle.fontSize = 14;
    textStyle.color = [CPTColor whiteColor];

    axisSet.xAxis.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0.0");
    axisSet.xAxis.minorTicksPerInterval       = 0;

    NSLog(@"C");
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    if ([person.unitPreference isEqualToString:@"US"]) {
        [dateFormatter setDateFormat:@"MMM-dd"];
    } else {
        [dateFormatter setDateFormat:@"dd-MMM"];
    }
    NSLog(@"D");
    CPTTimeFormatter *timeFormatter = [[CPTTimeFormatter alloc] initWithDateFormatter:dateFormatter];
    axisSet.xAxis.labelFormatter = timeFormatter;
    axisSet.xAxis.labelRotation = M_PI/4;
    axisSet.xAxis.titleOffset = 55.5f;
    axisSet.xAxis.labelingPolicy = CPTAxisLabelingPolicyAutomatic;    
    NSLog(@"E");
    if ([measurementField isEqualToString:@"mWeight"]) {
        NSString *unit;
        if ([person.unitPreference isEqualToString:@"METRIC"]) {
            unit = @"Kgs";
        } else if ([person.unitPreference isEqualToString:@"US"]) {
            unit = @"lbs";
        } else {
            unit = @"st lbs";
        }
        axisSet.yAxis.title = [NSString stringWithFormat: @"Weight (%@)", unit];

        WeightFormatter *weightFormatter = [[WeightFormatter alloc] init];
        weightFormatter.person = person;
        axisSet.yAxis.labelFormatter = weightFormatter;
    } else if ([measurementField isEqualToString:@"mBodyFatPercentage"]) {
        axisSet.yAxis.title = @"Body Fat %";
        axisSet.yAxis.labelFormatter = [[BodyFatPercentageFormatter alloc] init];
    } else {
        NSString *unit;
        if ([person.unitPreference isEqualToString:@"METRIC"]) {
            unit = @"CMs";
        } else {
            unit = @"Inches";
        }
        axisSet.yAxis.title = [NSString stringWithFormat: @"Measurements (%@)", unit];

        MeasurementFormatter *measurementFormatter = [[MeasurementFormatter alloc] init];
        measurementFormatter.person = person;
        axisSet.yAxis.labelFormatter = measurementFormatter;
    }
    NSLog(@"F");
    axisSet.yAxis.titleTextStyle = textStyle;
    axisSet.yAxis.titleOffset = 40.0f + marginOffset;
    axisSet.yAxis.axisLineStyle = lineStyle;
    axisSet.yAxis.majorTickLineStyle = lineStyle;
    axisSet.yAxis.minorTickLineStyle = lineStyle;
    axisSet.yAxis.labelTextStyle = textStyle;
    axisSet.yAxis.labelOffset = 3.0f;
    axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat((yAxisMax-yAxisMin)/10.0f);
    axisSet.yAxis.minorTicksPerInterval = 1;
    axisSet.yAxis.minorTickLength = 5.0f;
    axisSet.yAxis.majorTickLength = 7.0f;
    axisSet.yAxis.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
    axisSet.xAxis.orthogonalCoordinateDecimal = CPTDecimalFromFloat(yAxisMin);
    axisSet.xAxis.majorIntervalLength =  CPTDecimalFromFloat(oneDay);
    NSLog(@"G");
}

Answer 1

这是coreplot 1.2引入的内容。以下几行会导致应用程序挂起很长时间：

axisSet.xAxis.labelRotation = M_PI/4;
axisSet.xAxis.titleOffset = 55.5f;

恢复到1.1立即解决了问题。从@Eric Skroch上面的评论来看，这可能会在1.3中得到修复，但我希望在此之前使用稳定的版本，尤其是因为我没有使用1.2中的任何新功能。

顺便说一下，我认为旧图书馆没有使用我的iPhone 5的原因是没有以下内容：

在目标构建设置中添加到其他链接器标志：

-ObjC -all_load

Answer 2

将标签政策设置为无非常重要，以明确您将自定义x和y轴。

CPTAxis *x = axisSet.xAxis;

CPTAxis *y = axisSet.yAxis;

x.labelingPolicy = CPTAxisLabelingPolicyNone;
y.labelingPolicy = CPTAxisLabelingPolicyNone;

CorePlot性能缓慢

2 个答案: