Didn't find class "lecho.lib.hellocharts.view.LineChartView"

[yhzjut0503]

XML：
<lecho.lib.hellocharts.view.LineChartView
android:id="@+id/activity_main_curve_chart"
android:layout_width="fill_parent"
android:layout_height="@dimen/activity_main_curve_layout_height"
android:layout_margin="@dimen/activity_main_curve_layout_pad" />

err_log:
Caused by: java.lang.ClassNotFoundException: Didn't find class "lecho.lib.hellocharts.view.LineChartView" on path: DexPathList[[zip file "/data/app/com.android.growthnotesapp-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.android.growthnotesapp-2, /system/lib]]

development environment：
win10 64 bit operating system,Ecplise.2 Release (4.7.2),ADT 21.0.0

How to solve the problem？