OC呼叫Charts繪製圖表--BarChartView

多系列柱狀圖，這裡基本的就不說了，接著之前的文章，直接寫到資料賦值的處理：

    NSArray *array = @[@"17655.2", @"20939.38", @"36271.65", @"30353.48", @"26874.45", @"23715.13", @"24367.3", @"23408.85", @"24016.9", @"31424.75", @"26744.25", @"26307.8"];
    NSArray *array1 = @[@"17077.85", @"18197.63", @"29818.3", @"26785.3", @"26273.75", @"22973.3", @"23457.4", @"25208.25", @"27054.9", @"32088.15", @"24960.65", @"31157.2"];
    NSArray *array2= @[@"20155.2", @"19874.18", @"32059.85", @"25786.1", @"28643.8", @"26407.05", @"23894.45", @"23832.1", @"28999.18", @"35795.8", @"16169.15", @"--"];
    NSMutableArray *valueArray = [NSMutableArray array];
    [valueArray addObject:array];
    [valueArray addObject:array1];
    [valueArray addObject:array2];

    double dataSetMin = 0;
    double dataSetMax = 0;
    float groupSpace = 0.25f;
    float barSpace = 0.0f;
    float barWidth = 0.25f;
    
    NSMutableArray *dataSets = [NSMutableArray array];
    
    for (int i = 0; i < valueArray.count; i++) {
        NSMutableArray *yVals = [NSMutableArray array];
        BarChartDataSet *set = nil;
        NSArray *array = valueArray[i];
        for (int j = 0; j < array.count; j++)
        {
            double val = [array[j] doubleValue];
            dataSetMax = MAX(val, dataSetMax);
            dataSetMin = MIN(val, dataSetMin);
            [yVals addObject:[[BarChartDataEntry alloc]
                              initWithX:j
                              y:val]];
            set = [[BarChartDataSet alloc] initWithValues:yVals label:[NSString stringWithFormat:@"第%d個圖例",i]];
            [set setColor:self.colorArray[i]];
            set.valueColors = @[self.colorArray[i]];
        }
        [dataSets addObject:set];
    }
    double diff = dataSetMax - dataSetMin;
    
    if (dataSetMax == 0 && dataSetMin == 0) {
        dataSetMax = 100.0;
        dataSetMin = -10.0;
    } else {
        dataSetMax = (dataSetMax + diff * 0.2);
        dataSetMin = (dataSetMin - diff * 0.1);
    }
    self.barChartView.leftAxis.axisMaximum = dataSetMax;
    self.barChartView.leftAxis.axisMinimum = 0;
    
    BarChartData *data = [[BarChartData alloc] initWithDataSets:dataSets];
    [data setValueFont:[UIFont systemFontOfSize:10.f]];
    data.barWidth = barWidth;
    _barChartView.xAxis.axisMinimum = -0.1;
    _barChartView.xAxis.axisMaximum = 0 + [data groupWidthWithGroupSpace:groupSpace barSpace: barSpace] * 12;
    [data groupBarsFromX: 0 groupSpace: groupSpace barSpace: barSpace];
    
    _barChartView.data = nil;
    _barChartView.data = data;
    [self.barChartView animateWithXAxisDuration:0.25f];

效果圖如下：

多系列柱狀圖.png

多系列柱狀圖主要的幾行程式碼

float groupSpace = 0.25f;
float barSpace = 0.0f;
float barWidth = 0.25f;
// (barSpace + barWidth) * 系列數 + groupSpace = 1.00 -> interval per "group"
groupSpace 
groupSpace -- 組的間隔
barSpace -- 每組之間柱狀圖的間隔
barWidth -- 每組柱狀圖的寬度

單系列的柱狀圖更簡單，只需要設定barwidth就可以了 [data groupBarsFromX: 0 groupSpace: groupSpace barSpace: barSpace] 這句話可以不要，在折線和混合圖表裡面也有單系列的柱狀圖。