java - Android应用程序错误: "unfotunatley Application has stopped"

Question

我是android初学者，正在编写简单的程序来将设备的响铃状态更改为静音，反之亦然以下是我的代码和错误日志似乎错误日志给出了确切的错误消息，但我是真的无法得到它..请帮助我

错误日志

10-14 00:01:34.964: E/AndroidRuntime(771): FATAL EXCEPTION: main
10-14 00:01:34.964: E/AndroidRuntime(771): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.silentmodetoggle/com.example.silentmodetoggle.MainActivity}: java.lang.ClassCastException: android.widget.ImageView cannot be cast to android.widget.Button
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.os.Looper.loop(Looper.java:137)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread.main(ActivityThread.java:5041)
10-14 00:01:34.964: E/AndroidRuntime(771):  at java.lang.reflect.Method.invokeNative(Native Method)
10-14 00:01:34.964: E/AndroidRuntime(771):  at java.lang.reflect.Method.invoke(Method.java:511)
10-14 00:01:34.964: E/AndroidRuntime(771):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
10-14 00:01:34.964: E/AndroidRuntime(771):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
10-14 00:01:34.964: E/AndroidRuntime(771):  at dalvik.system.NativeStart.main(Native Method)
10-14 00:01:34.964: E/AndroidRuntime(771): Caused by: java.lang.ClassCastException: android.widget.ImageView cannot be cast to android.widget.Button
10-14 00:01:34.964: E/AndroidRuntime(771):  at com.example.silentmodetoggle.MainActivity.setButtonCliclListener(MainActivity.java:34)
10-14 00:01:34.964: E/AndroidRuntime(771):  at com.example.silentmodetoggle.MainActivity.onCreate(MainActivity.java:26)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.Activity.performCreate(Activity.java:5104)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
10-14 00:01:34.964: E/AndroidRuntime(771):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
10-14 00:01:34.964: E/AndroidRuntime(771):  ... 11 more

Java 文件

    public class MainActivity extends Activity 
    {
         private AudioManager audio; 
         private boolean issilent ; 
         ImageView  img;

        @Override
        protected void onCreate(Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            setButtonCliclListener();
            audio= (AudioManager) getSystemService(AUDIO_SERVICE);
            checkifsilent();
            setButtonCliclListener();

         }
        private  void setButtonCliclListener()
        {
            Button toggle=  (Button) findViewById(R.id.on_icon);
            toggle.setOnClickListener(new OnClickListener()
            {
                @Override
                public void onClick(View v) 
                {
                     if(issilent)
                     {
                         audio.setRingerMode(AudioManager.RINGER_MODE_SILENT);
                         issilent=true; 
                     }
                     else
                     {
                         audio.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
                         issilent= false; 
                     }
                }
            });
            toggleui();

        }


        public  void checkifsilent()
        {
             int ringermode= audio.getRingerMode();
             if(ringermode== AudioManager.RINGER_MODE_SILENT)
             {
                 issilent=true; 
             }
             else 
             {issilent=false; }
        }

        private void toggleui()
        {
             img=  (ImageView) findViewById(R.id.on_icon);
             Drawable newimg; 
             if(issilent)
            {
               newimg=getResources().getDrawable(R.drawable.off);
            }
             else 
             {
                 newimg= getResources().getDrawable(R.drawable.on);
             }

            img.setImageDrawable(newimg);
        }

        @Override
        public void onResume()
        {
            super.onResume();
             checkifsilent();
             toggleui();
        }

     }

XML

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/on_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:src="@drawable/on" />

    <Button
        android:id="@+id/Toggle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Toggle  Mode" />

</LinearLayout>

Answer 1

提示是，您在按钮引用中没有使用正确的 ID。

由于您是初学者，提示比给您简单的答案要有意义得多。