MPChartAndroid 在 Kotlin 错误空对象引用中的 Fragment tabslider 上崩溃
MPChartAndroid Crash on Fragment tabslider in Kotlin Error null object reference
请帮助我尝试在 Fragment 上显示 MPChartAndroid 时崩溃。一切正常，没有碎片。
这是我的 activity :
class Statistik : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.statistik);
//SliderTab Chart
val adapterChartKu = AdapterChartKu(supportFragmentManager)
adapterChartKu.addFragment(ClassPerTanggal(), "perTanggal")
adapterChartKu.addFragment(ClassPerOngkir(), "perOngkir")
adapterChartKu.addFragment(ClassPerJumlah(), "perJumlah")
adapterChartKu.addFragment(ClassPerBulan(), "perBulan")
viewChart.adapter = adapterChartKu
tabsChart.setupWithViewPager(viewChart)
setupBarChartData()
}
private fun setupBarChartData() {
// create BarEntry for Bar Group
val bargroup = ArrayList<BarEntry>()
bargroup.add(BarEntry(0f, 30f, "0"))
bargroup.add(BarEntry(1f, 2f, "1"))
bargroup.add(BarEntry(2f, 4f, "2"))
bargroup.add(BarEntry(3f, 6f, "3"))
bargroup.add(BarEntry(4f, 8f, "4"))
bargroup.add(BarEntry(5f, 10f, "5"))
bargroup.add(BarEntry(6f, 22f, "6"))
bargroup.add(BarEntry(7f, 12.5f, "7"))
bargroup.add(BarEntry(8f, 22f, "8"))
bargroup.add(BarEntry(9f, 32f, "9"))
bargroup.add(BarEntry(10f, 54f, "10"))
bargroup.add(BarEntry(11f, 28f, "11"))
// creating dataset for Bar Group
val barDataSet = BarDataSet(bargroup, "Test aja")
barDataSet.color = ContextCompat.getColor(this, R.color.colorAccent)
val data = BarData(barDataSet)
barChart.setData(data)
barCharts.setData(data)
barChart.xAxis.position = XAxis.XAxisPosition.BOTTOM
barChart.xAxis.labelCount = 11
barChart.xAxis.enableGridDashedLine(5f, 5f, 0f)
barChart.axisRight.enableGridDashedLine(5f, 5f, 0f)
barChart.axisLeft.enableGridDashedLine(5f, 5f, 0f)
barChart.description.isEnabled = false
barChart.animateY(1000)
barChart.legend.isEnabled = false
barChart.setPinchZoom(true)
barChart.data.setDrawValues(false)
}
还有我的片段：
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Statistik">
<!-- TODO: Update blank fragment layout -->
<com.github.mikephil.charting.charts.BarChart
android:id="@+id/barCharts"
android:layout_width="match_parent"
android:layout_height="300dp">
</com.github.mikephil.charting.charts.BarChart>
还有我的ActivityXML
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/CardBarChart"
android:layout_margin="5dp"
app:cardCornerRadius="6dp"
app:cardElevation="5dp"
app:layout_constraintTop_toBottomOf="@+id/GridTotalan">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="@+id/tabsChart"
android:layout_width="match_parent"
android:layout_height="35dp"
app:tabGravity="fill"
app:tabIndicatorColor="@color/colorPrimary"
app:tabIndicatorHeight="2dp"
app:tabMode="fixed"
app:tabPaddingEnd="14sp"
app:tabPaddingStart="14dp"
app:tabSelectedTextColor="@color/colorPrimary"
app:tabTextAppearance="@style/TabKecil" />
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewChart"
android:layout_width="match_parent"
android:layout_height="350dp">
</androidx.viewpager.widget.ViewPager>
</LinearLayout>
</androidx.cardview.widget.CardView>
这是我的片段xml
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/CardBarChart"
android:layout_margin="5dp"
app:cardCornerRadius="6dp"
app:cardElevation="5dp"
app:layout_constraintTop_toBottomOf="@+id/GridTotalan">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="@+id/tabsChart"
android:layout_width="match_parent"
android:layout_height="35dp"
app:tabGravity="fill"
app:tabIndicatorColor="@color/colorPrimary"
app:tabIndicatorHeight="2dp"
app:tabMode="fixed"
app:tabPaddingEnd="14sp"
app:tabPaddingStart="14dp"
app:tabSelectedTextColor="@color/colorPrimary"
app:tabTextAppearance="@style/TabKecil" />
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewChart"
android:layout_width="match_parent"
android:layout_height="350dp"
app:layout_constraintTop_toBottomOf="@+id/tabsChart">
</androidx.viewpager.widget.ViewPager>
</LinearLayout>
</androidx.cardview.widget.CardView>
FATAL EXCEPTION: main
Process: com.multiekspedisi.juarapaket, PID: 15237
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xxx.xxx/cxxxom.xxx.xxx.Statistik}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.github.mikephil.charting.charts.BarChart.setData(com.github.mikephil.charting.data.ChartData)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
我认为这是因为您在 activity 而不是片段中设置了图表，因为我认为您可能希望在 viewpager 中的片段中显示图表（来自片段 xml）
因此您的 Statistik class 仅包含选项卡和 viewpager
的设置
class Statistik : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.statistik);
//SliderTab Chart
val adapterChartKu = AdapterChartKu(supportFragmentManager)
adapterChartKu.addFragment(ClassPerTanggal(), "perTanggal")
adapterChartKu.addFragment(ClassPerOngkir(), "perOngkir")
adapterChartKu.addFragment(ClassPerJumlah(), "perJumlah")
adapterChartKu.addFragment(ClassPerBulan(), "perBulan")
viewChart.adapter = adapterChartKu
tabsChart.setupWithViewPager(viewChart)
}
然后将您的函数移动到您的片段并在 onActivityCreated
上调用它
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
setupBarChartData()
}
private fun setupBarChartData() {
// create BarEntry for Bar Group
val bargroup = ArrayList<BarEntry>()
bargroup.add(BarEntry(0f, 30f, "0"))
bargroup.add(BarEntry(1f, 2f, "1"))
bargroup.add(BarEntry(2f, 4f, "2"))
bargroup.add(BarEntry(3f, 6f, "3"))
bargroup.add(BarEntry(4f, 8f, "4"))
bargroup.add(BarEntry(5f, 10f, "5"))
bargroup.add(BarEntry(6f, 22f, "6"))
bargroup.add(BarEntry(7f, 12.5f, "7"))
bargroup.add(BarEntry(8f, 22f, "8"))
bargroup.add(BarEntry(9f, 32f, "9"))
bargroup.add(BarEntry(10f, 54f, "10"))
bargroup.add(BarEntry(11f, 28f, "11"))
// creating dataset for Bar Group
val barDataSet = BarDataSet(bargroup, "Test aja")
barDataSet.color = ContextCompat.getColor(this, R.color.colorAccent)
val data = BarData(barDataSet)
barCharts.setData(data) // barCharts instead of barChart, by the id in your fragment
barCharts.xAxis.position = XAxis.XAxisPosition.BOTTOM
barCharts.xAxis.labelCount = 11
barCharts.xAxis.enableGridDashedLine(5f, 5f, 0f)
barCharts.axisRight.enableGridDashedLine(5f, 5f, 0f)
barCharts.axisLeft.enableGridDashedLine(5f, 5f, 0f)
barCharts.description.isEnabled = false
barCharts.animateY(1000)
barCharts.legend.isEnabled = false
barCharts.setPinchZoom(true)
barCharts.data.setDrawValues(false)
}
请帮助我尝试在 Fragment 上显示 MPChartAndroid 时崩溃。一切正常，没有碎片。
这是我的 activity :
class Statistik : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.statistik);
//SliderTab Chart
val adapterChartKu = AdapterChartKu(supportFragmentManager)
adapterChartKu.addFragment(ClassPerTanggal(), "perTanggal")
adapterChartKu.addFragment(ClassPerOngkir(), "perOngkir")
adapterChartKu.addFragment(ClassPerJumlah(), "perJumlah")
adapterChartKu.addFragment(ClassPerBulan(), "perBulan")
viewChart.adapter = adapterChartKu
tabsChart.setupWithViewPager(viewChart)
setupBarChartData()
}
private fun setupBarChartData() {
// create BarEntry for Bar Group
val bargroup = ArrayList<BarEntry>()
bargroup.add(BarEntry(0f, 30f, "0"))
bargroup.add(BarEntry(1f, 2f, "1"))
bargroup.add(BarEntry(2f, 4f, "2"))
bargroup.add(BarEntry(3f, 6f, "3"))
bargroup.add(BarEntry(4f, 8f, "4"))
bargroup.add(BarEntry(5f, 10f, "5"))
bargroup.add(BarEntry(6f, 22f, "6"))
bargroup.add(BarEntry(7f, 12.5f, "7"))
bargroup.add(BarEntry(8f, 22f, "8"))
bargroup.add(BarEntry(9f, 32f, "9"))
bargroup.add(BarEntry(10f, 54f, "10"))
bargroup.add(BarEntry(11f, 28f, "11"))
// creating dataset for Bar Group
val barDataSet = BarDataSet(bargroup, "Test aja")
barDataSet.color = ContextCompat.getColor(this, R.color.colorAccent)
val data = BarData(barDataSet)
barChart.setData(data)
barCharts.setData(data)
barChart.xAxis.position = XAxis.XAxisPosition.BOTTOM
barChart.xAxis.labelCount = 11
barChart.xAxis.enableGridDashedLine(5f, 5f, 0f)
barChart.axisRight.enableGridDashedLine(5f, 5f, 0f)
barChart.axisLeft.enableGridDashedLine(5f, 5f, 0f)
barChart.description.isEnabled = false
barChart.animateY(1000)
barChart.legend.isEnabled = false
barChart.setPinchZoom(true)
barChart.data.setDrawValues(false)
}
还有我的片段：
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Statistik">
<!-- TODO: Update blank fragment layout -->
<com.github.mikephil.charting.charts.BarChart
android:id="@+id/barCharts"
android:layout_width="match_parent"
android:layout_height="300dp">
</com.github.mikephil.charting.charts.BarChart>
还有我的ActivityXML
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/CardBarChart"
android:layout_margin="5dp"
app:cardCornerRadius="6dp"
app:cardElevation="5dp"
app:layout_constraintTop_toBottomOf="@+id/GridTotalan">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="@+id/tabsChart"
android:layout_width="match_parent"
android:layout_height="35dp"
app:tabGravity="fill"
app:tabIndicatorColor="@color/colorPrimary"
app:tabIndicatorHeight="2dp"
app:tabMode="fixed"
app:tabPaddingEnd="14sp"
app:tabPaddingStart="14dp"
app:tabSelectedTextColor="@color/colorPrimary"
app:tabTextAppearance="@style/TabKecil" />
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewChart"
android:layout_width="match_parent"
android:layout_height="350dp">
</androidx.viewpager.widget.ViewPager>
</LinearLayout>
</androidx.cardview.widget.CardView>
这是我的片段xml
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/CardBarChart"
android:layout_margin="5dp"
app:cardCornerRadius="6dp"
app:cardElevation="5dp"
app:layout_constraintTop_toBottomOf="@+id/GridTotalan">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="@+id/tabsChart"
android:layout_width="match_parent"
android:layout_height="35dp"
app:tabGravity="fill"
app:tabIndicatorColor="@color/colorPrimary"
app:tabIndicatorHeight="2dp"
app:tabMode="fixed"
app:tabPaddingEnd="14sp"
app:tabPaddingStart="14dp"
app:tabSelectedTextColor="@color/colorPrimary"
app:tabTextAppearance="@style/TabKecil" />
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewChart"
android:layout_width="match_parent"
android:layout_height="350dp"
app:layout_constraintTop_toBottomOf="@+id/tabsChart">
</androidx.viewpager.widget.ViewPager>
</LinearLayout>
</androidx.cardview.widget.CardView>
FATAL EXCEPTION: main Process: com.multiekspedisi.juarapaket, PID: 15237 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xxx.xxx/cxxxom.xxx.xxx.Statistik}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.github.mikephil.charting.charts.BarChart.setData(com.github.mikephil.charting.data.ChartData)' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
我认为这是因为您在 activity 而不是片段中设置了图表，因为我认为您可能希望在 viewpager 中的片段中显示图表（来自片段 xml）
因此您的 Statistik class 仅包含选项卡和 viewpager
的设置class Statistik : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.statistik);
//SliderTab Chart
val adapterChartKu = AdapterChartKu(supportFragmentManager)
adapterChartKu.addFragment(ClassPerTanggal(), "perTanggal")
adapterChartKu.addFragment(ClassPerOngkir(), "perOngkir")
adapterChartKu.addFragment(ClassPerJumlah(), "perJumlah")
adapterChartKu.addFragment(ClassPerBulan(), "perBulan")
viewChart.adapter = adapterChartKu
tabsChart.setupWithViewPager(viewChart)
}
然后将您的函数移动到您的片段并在 onActivityCreated
上调用它override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
setupBarChartData()
}
private fun setupBarChartData() {
// create BarEntry for Bar Group
val bargroup = ArrayList<BarEntry>()
bargroup.add(BarEntry(0f, 30f, "0"))
bargroup.add(BarEntry(1f, 2f, "1"))
bargroup.add(BarEntry(2f, 4f, "2"))
bargroup.add(BarEntry(3f, 6f, "3"))
bargroup.add(BarEntry(4f, 8f, "4"))
bargroup.add(BarEntry(5f, 10f, "5"))
bargroup.add(BarEntry(6f, 22f, "6"))
bargroup.add(BarEntry(7f, 12.5f, "7"))
bargroup.add(BarEntry(8f, 22f, "8"))
bargroup.add(BarEntry(9f, 32f, "9"))
bargroup.add(BarEntry(10f, 54f, "10"))
bargroup.add(BarEntry(11f, 28f, "11"))
// creating dataset for Bar Group
val barDataSet = BarDataSet(bargroup, "Test aja")
barDataSet.color = ContextCompat.getColor(this, R.color.colorAccent)
val data = BarData(barDataSet)
barCharts.setData(data) // barCharts instead of barChart, by the id in your fragment
barCharts.xAxis.position = XAxis.XAxisPosition.BOTTOM
barCharts.xAxis.labelCount = 11
barCharts.xAxis.enableGridDashedLine(5f, 5f, 0f)
barCharts.axisRight.enableGridDashedLine(5f, 5f, 0f)
barCharts.axisLeft.enableGridDashedLine(5f, 5f, 0f)
barCharts.description.isEnabled = false
barCharts.animateY(1000)
barCharts.legend.isEnabled = false
barCharts.setPinchZoom(true)
barCharts.data.setDrawValues(false)
}