iOS 圖表工具charts之PieChartView

關於charts的系列視圖介紹傳送門：
iOS 圖表工具charts介紹
iOS 圖表工具charts之LineChartView
iOS 圖表工具charts之BarChartView
iOS 圖表工具charts之PieChartView
iOS 圖表工具charts之CandleStickChartView
iOS 圖表工具charts之CombinedChartView

PieChartView在charts中可以用來繪制餅狀圖,由於charts是基於swift開發的，如果需要和objective-C混編(通過pod的方式不用管)，可以參考我的上幾篇文章iOS OC中橋接swift第三方庫》，這里主要講的是PieChartView的一些常用屬性和一些基本用法，實際情況以開發為准

PieChartView的一下屬性介紹

    PieChartView *chartView = [[PieChartView alloc] init];
    //設置偏移
    [chartView setExtraOffsetsWithLeft:20 top:20 right:20 bottom:20];

    //無內容顯示
    chartView.noDataText = @"";
    //關閉描述
    chartView.chartDescription.enabled = YES;
    chartView.chartDescription.text = @"tiny`s barChart demo";
    //關閉圖例
    chartView.legend.enabled = YES;
    //將數據轉換為百分比
    chartView.usePercentValuesEnabled = YES;
    //慣性
    chartView.dragDecelerationFrictionCoef = 0.5;  //0 1 慣性
    //設置中間文字
    chartView.drawCenterTextEnabled = YES;
    chartView.centerText = @"我是中間文字";
    //顯示扇形區域文字
    chartView.drawEntryLabelsEnabled = YES;
    //可以旋轉
    chartView.rotationEnabled = YES;
    //扇區可點擊
    chartView.highlightPerTapEnabled = YES;
    //代理
    chartView.delegate = self;
    

PieChartDataEntry 每個扇形區域

    NSArray *datas = @[@"24",@"74",@"35"];
    NSArray *titles = @[@"Pie1",@"Pie2",@"Pie3"];
    NSMutableArray *array = [NSMutableArray array];
    for (int i = 0; i < datas.count; i++) {
        PieChartDataEntry *entry = [[PieChartDataEntry alloc] initWithValue:[datas[i] integerValue] label:titles[i]];
        [array addObject:entry];
    }

PieChartDataSet 多個PieChartDataEntry扇形區域組合在一起就成了一個餅狀圖

    PieChartDataSet *set = [[PieChartDataSet alloc] initWithEntries:array label:@"Pie DataSet"];

    //顏色(每個扇形區域可以單獨設置顏色)
    set.colors = @[UIColor.redColor,UIColor.blueColor,UIColor.cyanColor];
    set.entryLabelFont = [UIFont systemFontOfSize:20];
    set.entryLabelColor = [UIColor blackColor];
    set.drawIconsEnabled = NO;
    //    當餅狀圖帶折線時，dataSet.yValuePosition 數值的位置只有設置為
    //    PieChartValuePositionOutsideSlice，折線才會顯示，valueLine相關屬性才有用
    set.drawValuesEnabled = YES;
    set.valueFont = [UIFont systemFontOfSize:20];
    set.valueColors = @[UIColor.redColor,UIColor.blueColor,UIColor.cyanColor];
    set.yValuePosition = PieChartValuePositionOutsideSlice;
    set.valueLineColor = UIColor.greenColor;
    //格式化
    NSNumberFormatter *pFormatter = [[NSNumberFormatter alloc] init];
    pFormatter.numberStyle = NSNumberFormatterPercentStyle;
    pFormatter.maximumFractionDigits = 1;
    pFormatter.multiplier = @1.f;
    pFormatter.percentSymbol = @" %";
    set.valueFormatter = [[ChartDefaultValueFormatter alloc] initWithFormatter:pFormatter];
    
    //相鄰區塊之間的間距
    set.sliceSpace = 5;
    //扇形區域放大范圍
    set.selectionShift = 8;
    //動畫開始的角度
    
    PieChartData *data = [[PieChartData alloc] initWithDataSet:set];

    self.chartView.data = data;
    //動畫開啟
    [self.chartView animateWithXAxisDuration:2.0f easingOption:ChartEasingOptionEaseOutExpo];

一些需要注意的點：
1.點擊扇形區域可以縮放

1.設置PieChartView可點擊chartView.highlightPerTapEnabled = YES;
2.設置PieChartDataSet縮放系數set.selectionShift = 8;

2.扇形區域剛出來的時候動畫旋轉一定的角度

    [self.chartView animateWithXAxisDuration:2.0f easingOption:ChartEasingOptionEaseOutExpo];

3.扇形區域折線要顯示出來

1.當餅狀圖帶折線時，dataSet.yValuePosition 數值的位置只有設置為 PieChartValuePositionOutsideSlice，折線才會顯示，valueLine相關屬性才有用
2.    set.drawValuesEnabled = YES;
    set.valueFont = [UIFont systemFontOfSize:20];
    set.valueColors = @[UIColor.redColor,UIColor.blueColor,UIColor.cyanColor];
    set.yValuePosition = PieChartValuePositionOutsideSlice;
    set.valueLineColor = UIColor.greenColor;

4.扇形區域數值百分比格式化

    NSNumberFormatter *pFormatter = [[NSNumberFormatter alloc] init];
    pFormatter.numberStyle = NSNumberFormatterPercentStyle;
    pFormatter.maximumFractionDigits = 1;
    pFormatter.multiplier = @1.f;
    pFormatter.percentSymbol = @" %";
    set.valueFormatter = [[ChartDefaultValueFormatter alloc] initWithFormatter:pFormatter];

5.顯示扇形區域的描述文字

   1.設置文字可顯示 chartView.drawEntryLabelsEnabled = NO;
   2.每個扇形區域設置文字titles為對應的文字描述
        NSArray *datas = @[@"24",@"74",@"35"];
    NSArray *titles = @[@"Pie1",@"Pie2",@"Pie3"];
    NSMutableArray *array = [NSMutableArray array];
    for (int i = 0; i < datas.count; i++) {
        PieChartDataEntry *entry = [[PieChartDataEntry alloc] initWithValue:[datas[i] integerValue] label:titles[i]];
        [array addObject:entry];
    }

轉載請標注來源：https://www.cnblogs.com/qqcc1388/