Android 当从活动向广播接收器发送数据时,应用程序在startActivity上崩溃
我在MainActivity中创建了按钮和编辑文本,将输入的号码从MainActivity发送到广播接收器。但当我按下“发送”按钮时,应用程序会在startActivity上崩溃。但通常情况下,它在不使用startActivity的情况下工作。我在广播接收器内输入号码,这样我就不会使用startActivity应用程序而不会崩溃 这是活动代码:Android 当从活动向广播接收器发送数据时,应用程序在startActivity上崩溃,android,Android,我在MainActivity中创建了按钮和编辑文本,将输入的号码从MainActivity发送到广播接收器。但当我按下“发送”按钮时,应用程序会在startActivity上崩溃。但通常情况下,它在不使用startActivity的情况下工作。我在广播接收器内输入号码,这样我就不会使用startActivity应用程序而不会崩溃 这是活动代码: package com.example.myapplication; import android.content.Intent; import an
package com.example.myapplication;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
EditText Ed;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Ed=findViewById(R.id.number);
btn=findViewById(R.id.send);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i=new Intent(MainActivity.this,GelenSms.class);
Bundle b=new Bundle();
b.putString("data",Ed.getText().toString());
i.putExtras(b);
startActivity(i);
}
});
}
}
这是广播接收机代码:
package com.example.myapplication;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.PhoneNumberUtils;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;
public class GelenSms extends BroadcastReceiver {
static final String SMS_RECEIVED ="android.provider.Telephony.SMS_RECEIVED";
@Override
public void onReceive(Context context, Intent intent) {
String number=intent.getStringExtra("data");
if (intent.getAction().equals(SMS_RECEIVED)) {
Bundle bundle = intent.getExtras();
if (bundle != null) {
// get sms objects
Object[] pdus = (Object[]) bundle.get("pdus");
if (pdus.length == 0) {
return;
}
// large message might be broken into many
SmsMessage[] messages = new SmsMessage[pdus.length];
StringBuilder sb = new StringBuilder();
for (int i = 0; i < pdus.length; i++) {
messages[i] = SmsMessage.createFromPdu((byte[]) pdus[i]);
sb.append(messages[i].getMessageBody());
}
String sender = messages[0].getOriginatingAddress();
String message = sb.toString();
// apply sms filter
if (PhoneNumberUtils.compare(number, sender)) {
Toast.makeText(context,"message:"+message+"from:"+sender,Toast.LENGTH_SHORT).show();
}
}
}
当您单击按钮时,使用的是startActivity()方法,意图是:
intent(MainActivity.this,GelenSms.class)代码>
所以基本上,你应该去活动GelenSms…在你的情况下,这不是一个活动,而是一个广播接收器。
因此,要么创建活动GelenSms并在清单中声明它,要么使用sendBroadcast()方法发送广播,而不是startActivity()。
请看此链接:
}我尝试了sendBroadcast()而不是startActivity(),但应用程序再次崩溃。我认为问题在于logcat的错误是“您是否在AndroidManifest.xml中声明了此活动?”此错误是因为startActivity(I);你应该从MainActivity活动转到GelenSms活动。但是,在您的情况下,没有GelenSms活动。GelenSms是一个广播接收机。“触发”broadcastReceiver的唯一方法是使用sendBroadcast()方法。使用此方法时会出现什么错误?现在,错误是“由以下原因引起的:java.lang.NullPointerException:尝试在空对象引用上调用虚拟方法'boolean java.lang.String.equalsIgnoreCase(java.lang.String)'”。我像您一样使用了sad SendBroadcast(),这是您想要的代码。receiver、logacat error或mainacivty
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapplication">
<uses-permission android:name="android.permission.RECEIVE_SMS"/>
<uses-permission android:name="android.permission.READ_SMS"/>
<uses-permission android:name="android.permission.SEND_SMS"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity >
<receiver android:name=".GelenSms"
android:enabled="true"
android:exported="true">
<intent-filter android:priority="99999" >
<action android:name="android.provider.Telephony.SMS_RECEIVED" />
</intent-filter>
</receiver>
</application>
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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=".MainActivity">
<Button
android:id="@+id/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/number"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.362" />
</android.support.constraint.ConstraintLayout>
2019-03-12 14:44:24.187 8304-8304/com.example.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myapplication, PID: 8304
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.myapplication/com.example.myapplication.GelenSms}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1805)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1523)
at android.app.Activity.startActivityForResult(Activity.java:4225)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
at android.app.Activity.startActivityForResult(Activity.java:4183)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
at android.app.Activity.startActivity(Activity.java:4522)
at android.app.Activity.startActivity(Activity.java:4490)
at com.example.myapplication.MainActivity$1.onClick(MainActivity.java:27)
at android.view.View.performClick(View.java:5637)
at android.view.View$PerformClick.run(View.java:22429)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
public class MainActivity extends AppCompatActivity {
EditText Ed;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Ed=findViewById(R.id.number);
btn=findViewById(R.id.send);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent= new Intent(MainActivity.this,GelenSms.class);
intent.putExtra("data",Ed.getText().toString());
sendBroadcast(intent);
}
});
}