AndroidスタジオのJavaコード

Question

私は、テキストの一部を置き換えようとしていますが、下をクリックしても機能しません。名前を入力せずに下部をクリックすると、メッセージに「Hello Username」と表示され、名前を入力すると「Username」が名前に置き換えられます。ここまではコードです。おかげ

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.*; 

public class HelloAndroid extends AppCompatActivity implements OnClickListener { 

    private EditText name; 
    private TextView display; 
    private Button button; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_hello_android); 
     name = (EditText) findViewById(R.id.name); 
     display = (TextView) findViewById(R.id.display); 
     button = (Button) findViewById(R.id.button); 
     button.setOnClickListener(this); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.menu_hello_android, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 


     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @Override 
    public void onClick(View view) { 
     if (button == view) { 
      String message = "Hello, Username " + name.getText().toString() + "!"; 

      if (button == view) { 
       String username = "Hello " + name.getText().toString() + ""; 


       Toast toast = Toast.makeText(this, message, Toast.LENGTH_SHORT); 
       toast.show(); 
       display.setText(message); 

      } 
     } 
    } 
} 

Answer 1

You are enable to do this because may be you are not getting click here . Here is my code change it . 

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 

import java.util.ArrayList; 

public class HelloAndroid extends AppCompatActivity implements View.OnClickListener { 



    private EditText name; 
    private TextView display; 
    private Button button; 

    String message ; 



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


     name = (EditText) findViewById(R.id.name); 
     display = (TextView) findViewById(R.id.display); 
     button = (Button) findViewById(R.id.button); 
     button.setOnClickListener(this); 


    } 

    @Override 
    public void onClick(View v) { 
     switch (v.getId()) 
     { 
      case R.id.button : 
       if (name.getText().toString().isEmpty()) 
       { 
        message = "Hello username" ; 

       } 
       else { 
        message = "Hello "+name.getText().toString() ; 

       } 


      Toast toast = Toast.makeText(this, message, Toast.LENGTH_SHORT); 
        toast.show(); 
        display.setText(message); 
       break; 
     } 
    } 
}