将rpt分配给CrystalReportViewer时出现NullReferenceException

Question

我想将YearlyBookings.rpt绑定到我的CrystalReportViewer。 但CrystalReportViewer为空，为什么？

GenerateReports.aspx：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_dashboard"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="org.wega.mcfc.DashboardActivity" >

    <!-- Main Content -->
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:elevation="4dp"
            android:background="@color/colorPrimary"
            android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />


        ...
    </RelativeLayout>
</android.support.v4.widget.DrawerLayout>

GenerateReport.aspx.cs：

<CR:CrystalReportViewer ID="CrystalReport1" runat="server" AutoDataBind="True" Height="50px" ToolPanelView="None" ToolPanelWidth="200px" Width="350px" />