いつもお世話になっております。
Androidの開発をはじめて1時間目です。
サンプルアプリでHello worldと表示させた後にその文字を別の文字(Hello New World)に変更するだけで積んでしまいました。。。
コードはこちらになります。
java
1package jp.study.myapplication; 2 3import android.os.Bundle; 4import android.support.design.widget.FloatingActionButton; 5import android.support.design.widget.Snackbar; 6import android.support.v7.app.AppCompatActivity; 7import android.support.v7.widget.Toolbar; 8import android.view.View; 9import android.view.Menu; 10import android.view.MenuItem; 11import android.widget.TextView; 12 13public class MainActivity extends AppCompatActivity { 14 15 @Override 16 protected void onCreate(Bundle savedInstanceState) { 17 super.onCreate(savedInstanceState); 18 setContentView(R.layout.activity_main); 19 TextView textview = (TextView)findViewById(R.id.text); 20 textview.setText("Hello New World!!"); 21 22 Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 23 setSupportActionBar(toolbar); 24 25 FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 26 fab.setOnClickListener(new View.OnClickListener() { 27 @Override 28 public void onClick(View view) { 29 Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 30 .setAction("Action", null).show(); 31 } 32 }); 33 } 34 35 @Override 36 public boolean onCreateOptionsMenu(Menu menu) { 37 // Inflate the menu; this adds items to the action bar if it is present. 38 getMenuInflater().inflate(R.menu.menu_main, menu); 39 return true; 40 } 41 42 @Override 43 public boolean onOptionsItemSelected(MenuItem item) { 44 // Handle action bar item clicks here. The action bar will 45 // automatically handle clicks on the Home/Up button, so long 46 // as you specify a parent activity in AndroidManifest.xml. 47 int id = item.getItemId(); 48 49 //noinspection SimplifiableIfStatement 50 if (id == R.id.action_settings) { 51 return true; 52 } 53 54 return super.onOptionsItemSelected(item); 55 } 56}
ここから下がlog
java
101-04 23:48:55.439 15002-15002/? I/art: Not late-enabling -Xcheck:jni (already on) 201-04 23:48:55.508 15002-15002/jp.study.myapplication W/System: ClassLoader referenced unknown path: /data/app/jp.study.myapplication-2/lib/x86 301-04 23:48:55.633 15002-15002/jp.study.myapplication D/AndroidRuntime: Shutting down VM 401-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: FATAL EXCEPTION: main 501-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: Process: jp.study.myapplication, PID: 15002 601-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{jp.study.myapplication/jp.study.myapplication.MainActivity}: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.TextView 701-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) 801-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 901-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.-wrap11(ActivityThread.java) 1001-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 1101-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102) 1201-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148) 1301-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5417) 1401-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) 1501-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 1601-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 1701-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: Caused by: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.TextView 1801-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at jp.study.myapplication.MainActivity.onCreate(MainActivity.java:19) 1901-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:6237) 2001-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 2101-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 2201-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 2301-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.-wrap11(ActivityThread.java) 2401-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 2501-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102) 2601-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148) 2701-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5417) 2801-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) 2901-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 3001-04 23:48:55.635 15002-15002/jp.study.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 31
こんな感じになっています。
TextView textview = (TextView)findViewById(R.id.text);
部分がおかしいのだろうと思っているのですが。。。
よろしくお願いいたします。
回答2件
あなたの回答
tips
プレビュー
バッドをするには、ログインかつ
こちらの条件を満たす必要があります。