Android 優秀圖標庫MPAndroidChart之柱狀圖（適應百分之八十項目需求）

前言

在項目當中很多時候要對數據進行分析就要用到圖表，在gitHub上有很多優秀的圖表開源庫，今天給大家分享的就是MPAndroidChart中的柱狀圖。簡單介紹一下MPAndroidChart：他可以實現圖表的拖動，3D，局部查看，數據動態展示等功能。

官方源碼地址：github.com/PhilJay/MPA…

廢話就不多說了，先給看大家看看效果圖喲

操作步驟

第一步：需要將依賴的庫添加到你的項目中

implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0-alpha'
implementation 'com.google.android.material:material:1.0.0'

第二步：xml中

   <com.github.mikephil.charting.charts.BarChart
    android:id="@+id/chart1"
    android:layout_width="match_parent"
    android:layout_height="300dp"
    />

第三步：ValueFormatter.java

  /**
 * Class to format all values before they are drawn as labels.
 */
 public abstract class ValueFormatter implements IAxisValueFormatter, IValueFormatter {

/**
 * <b>DO NOT USE</b>, only for backwards compatibility and will be removed in future versions.
 *
 * @param value the value to be formatted
 * @param axis  the axis the value belongs to
 * @return formatted string label
 */
@Override
@Deprecated
public String getFormattedValue(float value, AxisBase axis) {
    return getFormattedValue(value);
}

/**
 * <b>DO NOT USE</b>, only for backwards compatibility and will be removed in future versions.
 * @param value           the value to be formatted
 * @param entry           the entry the value belongs to - in e.g. BarChart, this is of class BarEntry
 * @param dataSetIndex    the index of the DataSet the entry in focus belongs to
 * @param viewPortHandler provides information about the current chart state (scale, translation, ...)
 * @return formatted string label
 */
@Override
@Deprecated
public String getFormattedValue(float value, Entry entry, int dataSetIndex, ViewPortHandler viewPortHandler) {
    return getFormattedValue(value);
}

/**
 * Called when drawing any label, used to change numbers into formatted strings.
 *
 * @param value float to be formatted
 * @return formatted string label
 */
public String getFormattedValue(float value) {
    return String.valueOf(value);
}

/**
 * Used to draw axis labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param value float to be formatted
 * @param axis  axis being labeled
 * @return formatted string label
 */
public String getAxisLabel(float value, AxisBase axis) {
    return getFormattedValue(value);
}

/**
 * Used to draw bar labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param barEntry bar being labeled
 * @return formatted string label
 */
public String getBarLabel(BarEntry barEntry) {
    return getFormattedValue(barEntry.getY());
}

/**
 * Used to draw stacked bar labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param value        current value to be formatted
 * @param stackedEntry stacked entry being labeled, contains all Y values
 * @return formatted string label
 */
public String getBarStackedLabel(float value, BarEntry stackedEntry) {
    return getFormattedValue(value);
}

/**
 * Used to draw line and scatter labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param entry point being labeled, contains X value
 * @return formatted string label
 */
public String getPointLabel(Entry entry) {
    return getFormattedValue(entry.getY());
}

/**
 * Used to draw pie value labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param value    float to be formatted, may have been converted to percentage
 * @param pieEntry slice being labeled, contains original, non-percentage Y value
 * @return formatted string label
 */
public String getPieLabel(float value, PieEntry pieEntry) {
    return getFormattedValue(value);
}

/**
 * Used to draw radar value labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param radarEntry entry being labeled
 * @return formatted string label
 */
public String getRadarLabel(RadarEntry radarEntry) {
    return getFormattedValue(radarEntry.getY());
}

/**
 * Used to draw bubble size labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param bubbleEntry bubble being labeled, also contains X and Y values
 * @return formatted string label
 */
public String getBubbleLabel(BubbleEntry bubbleEntry) {
    return getFormattedValue(bubbleEntry.getSize());
}

/**
 * Used to draw high labels, calls {@link #getFormattedValue(float)} by default.
 *
 * @param candleEntry candlestick being labeled
 * @return formatted string label
 */
public String getCandleLabel(CandleEntry candleEntry) {
    return getFormattedValue(candleEntry.getHigh());
}

}

第四步：MyValueFormatter

    public class MyValueFormatter extends ValueFormatter{
private final DecimalFormat mFormat;
private String suffix;

public MyValueFormatter(String suffix) {
    mFormat = new DecimalFormat("0000");
    this.suffix = suffix;
}

@Override
public String getFormattedValue(float value) {
    return mFormat.format(value) + suffix;
}

@Override
public String getAxisLabel(float value, AxisBase axis) {
    if (axis instanceof XAxis) {
        return mFormat.format(value);
    } else if (value > 0) {
        return mFormat.format(value) + suffix;
    } else {
        return mFormat.format(value);
    }
}
}

第五步：MainAcyivity

  package detongs.hbqianze.him.linechart;
  import android.os.Bundle;
  import android.util.Log;
  import android.view.WindowManager;
  import android.widget.TextView;

  import androidx.appcompat.app.AppCompatActivity;

  import com.github.mikephil.charting.charts.BarChart;
  import com.github.mikephil.charting.components.XAxis;
  import com.github.mikephil.charting.components.YAxis;
  import com.github.mikephil.charting.data.BarData;
  import com.github.mikephil.charting.data.BarDataSet;
  import com.github.mikephil.charting.data.BarEntry;
  import com.github.mikephil.charting.interfaces.datasets.IBarDataSet;
  import  com.github.mikephil.charting.interfaces.datasets.IDataSet;
  import com.github.mikephil.charting.utils.ColorTemplate;

  import java.util.ArrayList;

  import detongs.hbqianze.him.linechart.chart.MyValueFormatter;
  import detongs.hbqianze.him.linechart.chart.ValueFormatter;

  public class MainActivity extends AppCompatActivity {

private BarChart chart;
private TextView te_cache;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);

    chart = findViewById(R.id.chart1);
    te_cache = findViewById(R.id.te_cache);

    chart.getDescription().setEnabled(false);

    //設置最大值條目，超出之後不會有值
    chart.setMaxVisibleValueCount(60);

    //分別在x軸和y軸上進行縮放
    chart.setPinchZoom(true);
    //設置剩餘統計圖的陰影
    chart.setDrawBarShadow(false);
    //設置網格佈局
    chart.setDrawGridBackground(true);
    //通過自定義一個x軸標籤來實現2,015 有分割符符bug
    ValueFormatter custom = new MyValueFormatter(" ");
    //獲取x軸線
    XAxis xAxis = chart.getXAxis();

    //設置x軸的顯示位置
    xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
    //設置網格佈局
    xAxis.setDrawGridLines(true);
    //圖表將避免第一個和最後一個標籤條目被減掉在圖表或屏幕的邊緣
    xAxis.setAvoidFirstLastClipping(false);
    //繪製標籤  指x軸上的對應數值 默認true
    xAxis.setDrawLabels(true);
    xAxis.setValueFormatter(custom);
    //縮放後x 軸數據重疊問題
    xAxis.setGranularityEnabled(true);
    //獲取右邊y標籤
    YAxis axisRight = chart.getAxisRight();
    axisRight.setStartAtZero(true);
    //獲取左邊y軸的標籤
    YAxis axisLeft = chart.getAxisLeft();
    //設置Y軸數值 從零開始
    axisLeft.setStartAtZero(true);

    chart.getAxisLeft().setDrawGridLines(false);
    //設置動畫時間
     chart.animateXY(600,600);

     chart.getLegend().setEnabled(true);

    getData();
    //設置柱形統計圖上的值
    chart.getData().setValueTextSize(10);
    for (IDataSet set : chart.getData().getDataSets()){
        set.setDrawValues(!set.isDrawValuesEnabled());
    }

}

public void getData(){
ArrayList<BarEntry> values = new ArrayList<>();
    Float aFloat = Float.valueOf("2015");
    Log.v("xue","aFloat+++++"+aFloat);
    BarEntry barEntry = new BarEntry(aFloat,Float.valueOf("100"));
BarEntry barEntry1 = new BarEntry(Float.valueOf("2016"),Float.valueOf("210"));
BarEntry barEntry2 = new BarEntry(Float.valueOf("2017"),Float.valueOf("300"));
BarEntry barEntry3 = new BarEntry(Float.valueOf("2018"),Float.valueOf("450"));
BarEntry barEntry4 = new BarEntry(Float.valueOf("2019"),Float.valueOf("300"));
    BarEntry barEntry5 = new BarEntry(Float.valueOf("2020"),Float.valueOf("650"));
    BarEntry barEntry6 = new BarEntry(Float.valueOf("2021"),Float.valueOf("740"));
values.add(barEntry);
values.add(barEntry1);
values.add(barEntry2);
values.add(barEntry3);
values.add(barEntry4);
values.add(barEntry5);
    values.add(barEntry6);
BarDataSet set1;

if (chart.getData() != null &&
        chart.getData().getDataSetCount() > 0) {
    set1 = (BarDataSet) chart.getData().getDataSetByIndex(0);
    set1.setValues(values);
    chart.getData().notifyDataChanged();
    chart.notifyDataSetChanged();
} else {
    set1 = new BarDataSet(values, "點折水");
    set1.setColors(ColorTemplate.VORDIPLOM_COLORS);
    set1.setDrawValues(false);

    ArrayList<IBarDataSet> dataSets = new ArrayList<>();
    dataSets.add(set1);

    BarData data = new BarData(dataSets);
    chart.setData(data);

    chart.setFitBars(true);
}
    //繪製圖表
chart.invalidate();

}

}

最後

文章寫到這裏就結束了，如果你覺得文章寫得不錯就給個讚唄？你的支持是我最大的動力！如果還有想了解MPAndroidChart其他屬性的小夥伴也可以給我留言哦。

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