Currently I use the MPAndroidChart from GITHUB and draw the piechart to display the two line text, each line has different color and different font size,I check the source codes
after study the source codes, i change the PieChartRenderer.java to change the
mCenterTextPaint.setColor(Color.parseColor("#333333"));
mCenterTextPaint.setTextSize(Utils.convertDpToPixel(20f));
mCenterTextPaint.setTextAlign(Align.CENTER);
then use the "\n" as a split to get the first line
int index = centerText.indexOf("\n");
Spannable tempSpannable = new SpannableString(centerText);
tempSpannable.setSpan(new RelativeSizeSpan(0.75f), 0, index, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
tempSpannable.setSpan(new ForegroundColorSpan(Color.parseColor("#999999")),
0, index, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
// If width is 0, it will crash. Always have a minimum of 1
mCenterTextLayout = new StaticLayout(tempSpannable, 0, centerText.length(),
mCenterTextPaint,
(int)Math.max(Math.ceil(mCenterTextLastBounds.width()), 1.f),
Layout.Alignment.ALIGN_NORMAL, 1.f, 0.f, false);
then get what i wanted is
Use public void setCenterText(CharSequence text)
on the chart and pass a SpannableString
as its argument. Style your SpannableString to your heart's content.
You can accomplish this without modifying MPAndroidChart source by nesting your com.github.mikephil.charting.charts.PieChart component and your center text within a RelativeLayout in your activity layout. You can use a LinearLayout component to format your center text rows.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
>
<com.github.mikephil.charting.charts.PieChart
android:id="@+id/pieChart"
android:layout_width="match_parent"
android:layout_height="match_parent">
</com.github.mikephil.charting.charts.PieChart>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:orientation="vertical">
<TextView
android:id="@+id/pieChartMonthlyAverage"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/ChartStat"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/ChartStatLabel"
android:text="@string/charts.label.average"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/ChartStatLabel"
android:layout_marginTop="-4dp"
android:text="@string/charts.label.monthly"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/ChartStatLabel"
android:layout_marginTop="-4dp"
android:text="@string/charts.label.bill"/>
</LinearLayout>
</RelativeLayout>
Be careful to place your LinearLayout containing your center text below your PieChart component. Here is the end result.
PieData data = new PieData(dataSet);
pieChart.setCenterText("Total Questions 5" );
pieChart.setCenterTextSize(14f);
pieChart.setCenterTextColor(Color.BLUE);