Question

Android新手，不知道我在这里做错了什么。当我尝试在模拟器中运行以下命令时，我设法通过按下Login按钮从MainActivity.java到Contacts.java。但是，当尝试通过按下发送按钮从Contacts.java移动到Success.java应用程序崩溃时，任何帮助将非常感激＆lt; 3：

MainActivity.java

public class MainActivity extends ActionBarActivity {

    Button mLogin;
    List<ContactList> Contacts = new ArrayList<ContactList>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        addListenerOnButton();
    }

    private void addListenerOnButton() {

        final Context context = this;

        mLogin = (Button)findViewById(R.id.buttonLogin);
        mLogin.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                Intent intent = new Intent(context, Contacts.class);
                startActivity(intent);
            }
        });

    }
}

Contacts.java

public class Contacts extends MainActivity {

   private Button mSend;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.contacts);

        Context Toastie = getApplicationContext();
        CharSequence text = "Welcome!";
        int duration = Toast.LENGTH_SHORT;

        Toast toast = Toast.makeText(Toastie, text, duration);
        toast.show();

    }

    private void addListenerOnButton() {

        final Context context = this;

        mSend = (Button)findViewById(R.id.buttonSend);
        mSend.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg1) {
                Intent intent = new Intent(context, Success.class);
                startActivity(intent);

            }
        });
    }

Success.java

public class Success extends Contacts {

    private Button mRepeat;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.success);

        Context Toaster = getApplicationContext();
        CharSequence text = "Congratulations!!!!";
        int duration = Toast.LENGTH_SHORT;

        Toast toast = Toast.makeText(Toaster, text, duration);
        toast.show();
    }

Logcat（全部变为红色）：

    java.lang.IllegalStateException: Could not find a method Send(View) in the activity class com.sharansoni.www.messenger.Contacts for onClick handler on view class android.support.v7.widget.AppCompatButton with id 'buttonSend'
            at android.view.View$1.onClick(View.java:4007)
            at android.view.View.performClick(View.java:4780)
            at android.view.View$PerformClick.run(View.java:19866)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5257)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
     Caused by: java.lang.NoSuchMethodException: Send [class android.view.View]
            at java.lang.Class.getMethod(Class.java:664)
            at java.lang.Class.getMethod(Class.java:643)
            at android.view.View$1.onClick(View.java:4000)
            at android.view.View.performClick(View.java:4780)
            at android.view.View$PerformClick.run(View.java:19866)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5257)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

Contacts.class

R.layout.contacts   in this layout find your button(R.id.buttonSend) and in xml remove 
android:onClick=&...

Context Toaster = getApplicationContext(); - 那是错的在所有课程中尝试使用下一个

Toast toast = Toast.makeText(this, text, duration);

也不要使用变量的大写命名。

Android类错误 - 将屏幕移动到屏幕

1 个答案: