Java 无法为Compass活动实例化活动
我正在开发一个指南针应用程序,Java 无法为Compass活动实例化活动,java,android,android-activity,android-sensors,sensormanager,Java,Android,Android Activity,Android Sensors,Sensormanager,我正在开发一个指南针应用程序, SensorManager在onCreate()方法中初始化,并使用onSensorChanged()方法对其进行移动或设置动画 应用程序运行和崩溃时没有给出任何输出,我也检查了LogCat,但无法解决主要问题,需要指导 MainActivity.JAVA package com.jdev.truenorthcompass; import android.hardware.Sensor; import android.hardware.SensorEvent;
SensorManager
在onCreate()
方法中初始化,并使用onSensorChanged()
方法对其进行移动或设置动画
应用程序运行和崩溃时没有给出任何输出,我也检查了LogCat
,但无法解决主要问题,需要指导
MainActivity.JAVA
package com.jdev.truenorthcompass;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
import android.widget.TextView;
public abstract class MainActivity extends Activity implements SensorEventListener{
private ImageView image;
private float currentDegree = 0f;
private SensorManager mSensorManager;
TextView tvHeading;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
image = (ImageView)findViewById(R.id.imageViewCompass);
tvHeading = (TextView) findViewById(R.id.tvHeading);
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
}
@SuppressWarnings("deprecation")
@Override
protected void onResume(){
super.onResume();
mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION), SensorManager.SENSOR_DELAY_GAME);
}
@Override
protected void onPause(){
super.onPause();
mSensorManager.unregisterListener(this);
}
public void OnSensorChanged(SensorEvent event){
float degree = Math.round(event.values[0]);
tvHeading.setText("Heading:" + Float.toString(degree)+ "degrees");
RotateAnimation ra = new RotateAnimation(
currentDegree,
-degree,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
ra.setDuration(210);
ra.setFillAfter(true);
image.startAnimation(ra);
currentDegree = -degree;
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy){
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
对于文本视图,
用于显示用户的当前标题。ImageView
包含指南针图像,该图像使用MainActivity.java
中的代码像指南针一样被设置动画。
活动\u main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fff" >
<TextView
android:id="@+id/tvHeading"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginBottom="40dp"
android:layout_marginTop="20dp"
android:text="Heading: 0.0" />
<ImageView
android:id="@+id/imageViewCompass"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignTop="@+id/tvHeading"
android:layout_marginTop="20dp"
android:src="@drawable/img_compass" />
任何帮助都将不胜感激。谢谢大家!
还有Manifest.XML
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<application
...
<activity
android:name="com.jdev.truenorthcompass.MainActivity"
...
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
您的类是abstract
public abstract class MainActivity
抽象类不能直接实例化您的类是抽象的
public abstract class MainActivity
抽象类不能直接实例化谢谢,先生,很好的帮助谢谢,先生,很好的帮助