java - Android - 不同实现的切换 Activity

Question

我有 2 个 Java 类，它们是 2 个不同的 Activity ，我想通过单击按钮进行切换。

问题是，当我单击按钮时，应用程序崩溃了。

我的MainActivity扩展了Activity，我的SecondActivity扩展了Activity并实现了SensorEventListener 。所以我认为这就是问题所在。我的 MainActivity 无法实现 SensorEventListener 因为我使用的是外部传感器。

这是我的主要 Activity

public class MainActivity extends Activity {

//My Code goes here.

//This it the function that gets called from XML's onClick feature when I click my Button
public void gotoPathFinder(View v) {

    Intent intent = new Intent(this, pathfinderActivity.class);
    startActivity(intent);
}
}

这是我的第二个 Activity

package ca.concordia.sensortag.minimal;

import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;

public class pathfinderActivity extends Activity implements SensorEventListener {

    private SensorManager mSensorManager;
    private Sensor mStepCounterSensor;
    private Sensor mStepDetectorSensor;

    private TextView textView;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);

        mSensorManager = (SensorManager) getSystemService(this.SENSOR_SERVICE);
        mStepCounterSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
        mStepDetectorSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_STEP_DETECTOR);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
//      Sensor sensor = event.sensor;
//      float[] values = event.values;
//      int value = -1;
//
//      if (values.length > 0) {
//          value = (int) values[0];
//      }
//
//      if (sensor.getType() == Sensor.TYPE_STEP_COUNTER) {
//          textView.setText("Step Counter Detected : " + value);
//      } else if (sensor.getType() == Sensor.TYPE_STEP_DETECTOR) {
//          textView.setText("Step Detector Detected : " + value);
//      }
    }

    @Override
    protected void onResume() {

        super.onResume();

        mSensorManager.registerListener(this, mStepCounterSensor,SensorManager.SENSOR_DELAY_FASTEST);      
        mSensorManager.registerListener(this, mStepDetectorSensor,SensorManager.SENSOR_DELAY_FASTEST);

    }

    @Override
    protected void onStop() {
        super.onStop();
        mSensorManager.unregisterListener(this, mStepCounterSensor);
        mSensorManager.unregisterListener(this, mStepDetectorSensor);
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // TODO Auto-generated method stub

    }

}

所以我认为应用程序崩溃是因为我试图从未实现sensoreventlistener的 Activity 切换到实现sensoreventlistener的 Activity ？我该如何解决这个问题？

<小时/>

日志猫

11-27 20:00:07.312: W/dalvikvm(31178): threadid=1: thread exiting with uncaught exception (group=0x41604ba8)
11-27 20:00:07.312: E/AndroidRuntime(31178): FATAL EXCEPTION: main
11-27 20:00:07.312: E/AndroidRuntime(31178): Process: ca.concordia.sensortag.minimal, PID: 31178
11-27 20:00:07.312: E/AndroidRuntime(31178): java.lang.IllegalStateException: Could not find a method gotoPathFinder(View) in the activity class ca.concordia.sensortag.minimal.pathfinderActivity for onClick handler on view class android.widget.ImageView with id 'pf_button'
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.view.View$1.onClick(View.java:3810)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.view.View.performClick(View.java:4438)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.view.View$PerformClick.run(View.java:18422)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.os.Handler.handleCallback(Handler.java:733)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.os.Handler.dispatchMessage(Handler.java:95)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.os.Looper.loop(Looper.java:136)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.app.ActivityThread.main(ActivityThread.java:5017)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at java.lang.reflect.Method.invokeNative(Native Method)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at java.lang.reflect.Method.invoke(Method.java:515)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at dalvik.system.NativeStart.main(Native Method)
11-27 20:00:07.312: E/AndroidRuntime(31178): Caused by: java.lang.NoSuchMethodException: gotoPathFinder [class android.view.View]
11-27 20:00:07.312: E/AndroidRuntime(31178):    at java.lang.Class.getConstructorOrMethod(Class.java:472)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at java.lang.Class.getMethod(Class.java:857)
11-27 20:00:07.312: E/AndroidRuntime(31178):    at android.view.View$1.onClick(View.java:3803)
11-27 20:00:07.312: E/AndroidRuntime(31178):    ... 11 more

注意:当我单击该按钮时，它会将我带到相同的 Activity ...然后我再次单击该按钮，然后我收到错误

<小时/>

MainActivity 的 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="@drawable/bg"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="ca.concordia.sensortag.minimal.MainActivity$PlaceholderFragment" >

    <ImageView
        android:id="@+id/compass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@drawable/compass" />

    <ImageView
        android:id="@+id/pointer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@drawable/pointer" />

    <TextView
        android:id="@+id/degree"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/imageView1"
        android:layout_centerHorizontal="true"
        android:text="TextView" />

    <ImageView
        android:id="@+id/pf_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/compass"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="20dp"
        android:src="@drawable/pf_button"
        android:onClick="gotoPathFinder" />

</RelativeLayout>

Answer 1

您的 pathfinderActivity 类中没有 gotoPathFinder 方法，我是否正确，您在此类中也有一个带有 onclick 事件的 View 来调用此方法？

你在第二堂课上这样做:

setContentView(R.layout.activity_main);

所以你的第二个类(class)的布局与你的第一个类(class)相同。第一次单击按钮时， Activity 会发生变化，但布局保持不变，然后当您再次单击它时，当前类中没有按钮 onclick 可以运行并切换到其他类的方法

因此，如果您想使用 2 个单独的布局，请使用上面的单独布局进行切换

setContentView(R.layout.other_acticity);

如果有意的话，则将具有相同名称的方法添加到第二类