错误，如果我删除那些行一切都很好......
MainActivity.java
package com.vibrator;
import android.annotation.SuppressLint;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.os.Vibrator;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;
@SuppressLint("ShowToast")
public class MainActivity extends ActionBarActivity implements OnCheckedChangeListener, OnSeekBarChangeListener{
ToggleButton tbutton;
Vibrator v;
int i;
int j;
TextView txt;
SeekBar sb;
TextView txt1;
SeekBar sb1;
Spinner spinner1;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActionBar bar = getSupportActionBar();
bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#336699")));
spinner1 = (Spinner) findViewById(R.id.spinner);
Resources res=getResources();
String str[]=res.getStringArray(R.array.spinner2);
// Create an ArrayAdapter using the string array and a default spinner layout
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, str);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
spinner1.setAdapter(adapter);
//creating instance for vibrator
v=(Vibrator) getSystemService(VIBRATOR_SERVICE);
//checking if the device has vibrator or not
if(v!=null){
setContentView(R.layout.activity_main);
}
else {
setContentView(R.layout.secound);
}
//Log.e("vibrate", "setcontentview");
//creating instance of toggle buttton and setting listener
tbutton=(ToggleButton) findViewById(R.id.tb1);
tbutton.setOnCheckedChangeListener(this);
}
@Override
public void onCheckedChanged(CompoundButton arg0, boolean arg1) {
Log.d("real status", ""+arg1);
//if vibrator is ON
if(arg1)
{
Log.d("vibrate", "if loop");
Toast.makeText(this,"status: "+arg1, Toast.LENGTH_LONG).show();
//creating instance of seekbar and textview
sb=(SeekBar) findViewById(R.id.seekbar);
txt=(TextView) findViewById(R.id.txt12);
sb1=(SeekBar) findViewById(R.id.seekbar1);
txt1=(TextView) findViewById(R.id.txt11);
//changing visibility
txt.setVisibility(View.VISIBLE);
sb.setVisibility(View.VISIBLE);
txt1.setVisibility(View.VISIBLE);
sb1.setVisibility(View.VISIBLE);
sb1.setOnSeekBarChangeListener(this);
sb.setOnSeekBarChangeListener(this);
// Start without a delay
// Vibrate for 100 j milliseconds
// Sleep for 1000 (i) milliseconds
long[] pattern = {0, j, i};
// The '0' here means to repeat indefinitely
// '-1' would play the vibration once
v.vibrate(pattern, 0);
}
else {
sb.setVisibility(View.INVISIBLE);
txt.setVisibility(View.INVISIBLE);
sb1.setVisibility(View.INVISIBLE);
txt1.setVisibility(View.INVISIBLE);
Log.d("vibrate", "else loop");
Toast.makeText(this,"status: "+arg1, Toast.LENGTH_LONG).show();
v.cancel();
}
}
@Override
public void onProgressChanged(SeekBar s, int v, boolean b) {
tbutton.setChecked(false);
switch (s.getId()) {
case R.id.seekbar:
i=v;
break;
case R.id.seekbar1:
j=v;
break;
}
txt.setText("Vibrator OFF time: "+i);
txt1.setText("Vibrator ON time: "+j);
tbutton.setChecked(true);
}
@Override
public void onStartTrackingTouch(SeekBar arg0) {
}
@Override
public void onStopTrackingTouch(SeekBar arg0) {
}
}
当我运行项目时，我没有为微调器项设置任何监听器，它给出了运行时和nullpointer异常。
activity_main.xml中
<?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"
android:background="#363636"
>
<ToggleButton
android:id="@+id/tb1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:textOn="OFF "
android:layout_marginTop="2dp"
android:layout_marginBottom="2dp"
android:textOff="ON"
/>
<RelativeLayout
android:id="@+id/rl"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<SeekBar
android:id="@+id/seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/txt12"
android:max="100"
android:progress="15"
android:visibility="gone"
/>
<TextView
android:id="@+id/txt12"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="@string/sleep"
android:textColor="#D5D5D5"
android:visibility="gone" />
</RelativeLayout>
<RelativeLayout
android:id="@+id/rl1"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<SeekBar
android:id="@+id/seekbar1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/txt11"
android:max="100"
android:progress="15"
android:visibility="gone"
/>
<TextView
android:id="@+id/txt11"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="@string/wake"
android:textColor="#D5D5D5"
android:visibility="gone" />
</RelativeLayout>
<Spinner
android:id="@+id/spinner"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="visible"/>
</LinearLayout>
的strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Vibrator</string>
<string name="hello_world">Hello world!</string>
<string name="action_settings">Settings</string>
<string name="notsupported">device not supported</string>
<string name="sleep">Vibrator ON time: 15</string>
<string name="wake">Vibrator OFF time: 15</string>
<string-array name="spinner2">
<item>Vibration Patterns</item>
<item>Pattern 1</item>
<item>Pattern 2</item>
<item>Pattern 3</item>
<item>Pattern 4</item>
<item>Pattern 5</item>
</string-array>
</resources>
logcat的
07-28 14:04:36.872: E/AndroidRuntime(739): FATAL EXCEPTION: main
07-28 14:04:36.872: E/AndroidRuntime(739): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.vibrator/com.vibrator.MainActivity}: java.lang.NullPointerException
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.os.Handler.dispatchMessage(Handler.java:99)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.os.Looper.loop(Looper.java:123)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-28 14:04:36.872: E/AndroidRuntime(739): at java.lang.reflect.Method.invokeNative(Native Method)
07-28 14:04:36.872: E/AndroidRuntime(739): at java.lang.reflect.Method.invoke(Method.java:521)
07-28 14:04:36.872: E/AndroidRuntime(739): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-28 14:04:36.872: E/AndroidRuntime(739): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-28 14:04:36.872: E/AndroidRuntime(739): at dalvik.system.NativeStart.main(Native Method)
07-28 14:04:36.872: E/AndroidRuntime(739): Caused by: java.lang.NullPointerException
07-28 14:04:36.872: E/AndroidRuntime(739): at com.vibrator.MainActivity.onCreate(MainActivity.java:50)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-28 14:04:36.872: E/AndroidRuntime(739): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-28 14:04:36.872: E/AndroidRuntime(739): ... 11 more
答案 0 :(得分：0)
错误就在这里`
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, R.array.spinner2,android.R.layout.simple_spinner_item)
` 您没有传递任何数组来向微调器添加项目，请执行以下代码片段
ArrayAdapter<String> myAdapter2=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,yourArray);//your array is holding the values to be displayedin the spinner,in arraylist
答案 1 :(得分：0)
我认为您的订单已更改。数组值（R.array.spinner2）应该在最后。请尝试以下代码。
String[] spinner2Array = getResources().getStringArray(R.array.spinner2);
ArrayAdapter<String> myAdapter2=new ArrayAdapter<String> (this,android.R.layout.simple_spinner_item,spinner2Array);