Android Kotlin异常:指定为非null的参数为null
我在Android Kotlin异常:指定为非null的参数为null,android,kotlin,Android,Kotlin,我在if(text.startsWith(prefix))行得到异常。怎么会?这到底是怎么回事 这是我的密码 CustomEditText.kt import android.content.Context import android.util.AttributeSet import android.widget.EditText class CustomEditText : EditText { private val prefix: String = "AS" con
if(text.startsWith(prefix))
行得到异常。怎么会?这到底是怎么回事
这是我的密码
CustomEditText.kt
import android.content.Context
import android.util.AttributeSet
import android.widget.EditText
class CustomEditText : EditText {
private val prefix: String = "AS"
constructor(context: Context) : super(context)
constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int, defStyleRes: Int) : super(context, attrs, defStyleAttr, defStyleRes)
override fun onSelectionChanged(selStart: Int, selEnd: Int) {
super.onSelectionChanged(selStart, selEnd)
if (text.startsWith(prefix)) {
// do something
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.example.myapplication.CustomEditText
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
堆栈跟踪
2019-11-28 15:58:46.623 11608-11608/com.example.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myapplication, PID: 11608
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myapplication/com.example.myapplication.MainActivity}: android.view.InflateException: Binary XML file line #7: Binary XML file line #7: Error inflating class com.example.myapplication.CustomEditText
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2821)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2929)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1623)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6678)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:830)
Caused by: android.view.InflateException: Binary XML file line #7: Binary XML file line #7: Error inflating class com.example.myapplication.CustomEditText
Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class com.example.myapplication.CustomEditText
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
at android.view.LayoutInflater.createView(LayoutInflater.java:647)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:469)
at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at com.example.myapplication.MainActivity.onCreate(MainActivity.java:12)
at android.app.Activity.performCreate(Activity.java:7023)
at android.app.Activity.performCreate(Activity.java:7014)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2774)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2929)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1623)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6678)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:830)
Caused by: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter prefix
at kotlin.text.StringsKt__StringsKt.startsWith(Unknown Source:7)
at kotlin.text.StringsKt__StringsKt.startsWith$default(Strings.kt:749)
at com.example.myapplication.CustomEditText.onSelectionChanged(CustomEditText.kt:21)
at android.widget.TextView.spanChange(TextView.java:9662)
at android.widget.TextView$ChangeWatcher.onSpanAdded(TextView.java:12121)
at android.text.SpannableStringBuilder.sendSpanAdded(SpannableStringBuilder.java:1272)
at android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:773)
at android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:672)
at android.text.Selection.setSelection(Selection.java:78)
2019-11-28 15:58:46.624 11608-11608/com.example.myapplication E/AndroidRuntime: at android.text.Selection.setSelection(Selection.java:87)
at android.text.method.ArrowKeyMovementMethod.initialize(ArrowKeyMovementMethod.java:312)
at android.widget.TextView.setText(TextView.java:5532)
at android.widget.TextView.setText(TextView.java:5400)
at android.widget.EditText.setText(EditText.java:113)
at android.widget.TextView.<init>(TextView.java:1652)
at android.widget.EditText.<init>(EditText.java:88)
at android.widget.EditText.<init>(EditText.java:84)
at android.widget.EditText.<init>(EditText.java:80)
at com.example.myapplication.CustomEditText.<init>(CustomEditText.kt:13)
... 26 more
2019-11-28 15:58:46.623 11608-11608/com.example.myapplication E/AndroidRuntime:致命异常:main
进程:com.example.myapplication,PID:11608
java.lang.RuntimeException:无法启动活动组件信息{com.example.myapplication/com.example.myapplication.MainActivity}:android.view.InflateException:二进制XML文件行#7:二进制XML文件行#7:膨胀类com.example.myapplication.CustomEditText时出错
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2821)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2929)
位于android.app.ActivityThread.-wrap11(未知来源:0)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1623)
位于android.os.Handler.dispatchMessage(Handler.java:106)
位于android.os.Looper.loop(Looper.java:164)
位于android.app.ActivityThread.main(ActivityThread.java:6678)
位于java.lang.reflect.Method.invoke(本机方法)
位于com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:830)
原因:android.view.InflateException:二进制XML文件行#7:二进制XML文件行#7:错误膨胀类com.example.myapplication.CustomEditText
原因:android.view.InflateException:二进制XML文件行#7:错误膨胀类com.example.myapplication.CustomEditText
原因:java.lang.reflect.InvocationTargetException
位于java.lang.reflect.Constructor.newInstance0(本机方法)
位于java.lang.reflect.Constructor.newInstance(Constructor.java:334)
位于android.view.LayoutInflater.createView(LayoutInflater.java:647)
位于android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790)
位于android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
位于android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
位于android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
在android.view.LayoutInflater.充气(LayoutInflater.java:515)
在android.view.LayoutInflater.充气(LayoutInflater.java:423)
在android.view.LayoutInflater.inflate(LayoutInflater.java:374)
位于androidx.appcompat.app.appcompatedelegateimpl.setContentView(appcompatedelegateimpl.java:469)
位于androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
位于com.example.myapplication.MainActivity.onCreate(MainActivity.java:12)
位于android.app.Activity.performCreate(Activity.java:7023)
位于android.app.Activity.performCreate(Activity.java:7014)
位于android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2774)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2929)
位于android.app.ActivityThread.-wrap11(未知来源:0)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1623)
位于android.os.Handler.dispatchMessage(Handler.java:106)
位于android.os.Looper.loop(Looper.java:164)
位于android.app.ActivityThread.main(ActivityThread.java:6678)
位于java.lang.reflect.Method.invoke(本机方法)
位于com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:830)
原因:java.lang.IllegalArgumentException:指定为非null的参数为null:方法kotlin.jvm.internal.Intrinsics.checkParametersNotnull,参数前缀
位于kotlin.text.StringsKt\uuu StringsKt.startsWith(未知来源:7)
在kotlin.text.StringsKt\uuu StringsKt.startsWith$default(Strings.kt:749)处
在com.example.myapplication.CustomEditText.onSelectionChanged(CustomEditText.kt:21)上
在android.widget.TextView.spanChange(TextView.java:9662)
在android.widget.TextView$ChangeWatcher.onSpanAdded(TextView.java:12121)
在android.text.SpannableStringBuilder.sendSpanAdded处(SpannableStringBuilder.java:1272)
位于android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:773)
位于android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:672)
位于android.text.Selection.setSelection(Selection.java:78)
2019-11-28 15:58:46.624 11608-11608/com.example.myapplication E/AndroidRuntime:at-android.text.Selection.setSelection(Selection.java:87)
在android.text.method.ArrowKeyMovementMethod.initialize(ArrowKeyMovementMethod.java:312)中
位于android.widget.TextView.setText(TextView.java:5532)
位于android.widget.TextView.setText(TextView.java:5400)
位于android.widget.EditText.setText(EditText.java:113)
位于android.widget.TextView。(TextView.java:1652)
在android.widget.EditText.(EditText.java:88)
在android.widget.EditText.(EditText.java:84)
在android.widget.EditText.(EditText.java:80)
在com.example.myapplication.CustomEditText.(CustomEditText.kt:13)
... 26多
在进行此类操作时,请将let函数与safecall(?)运算符一起使用。
使用Let关键字,块在获得非空值时将异常
用法:
text?.let {
// run this code if your 'text' is not null ..
}
当您进行此类操作时,请将let函数与safecall(?)运算符一起使用。 使用Let关键字,块在获得非空值时将异常 用法:
text?.let {
// run this code if your 'text' is not null ..
}
在JVM(包括Android)中,超类构造函数体在子类字段初始值设定项之前运行。既然你能看到那条线
at android.widget.TextView.<init>(TextView.java:1652)
同样,所以可能text
也是空的(您必须检查实现)。。。
at android.widget.EditText.setText(EditText.java:113)