Android Studio：單擊按鈕時無吐司消息

Question

我做了吐司按摩，應該在單擊按鈕時顯示，但那不會發生

public class CreateEmailActivity extends AppCompatActivity {

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

        Button send = findViewById(R.id.bntSendMail);

        send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getApplicationContext(),"Sending...",Toast.LENGTH_SHORT).show();
            }
        });
    }
    ...
    ...
}

Answer 1

您可以嘗試以下方法：

public class CreateEmailActivity extends Activity implements View.OnClickListener { 

    //Declare Button 
    Button send; 

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

        //Intialize Button 
        send = (Button) findViewById(R.id.bntSendMail);

        send.setOnClickListener(CreateEmailActivity.this); 

    } 

    @Override 
    public void onClick(View v) {

        switch(v.getId()) { 
            case R.id.bntSendMail: 
                Toast.makeText(this, "Sending...",Toast.LENGTH_SHORT).show();
                break;

        }

    }
}

我認為問題在於如何初始化按鈕，但是通過這種方式，您可以以更簡潔的方式處理更多的點擊事件。

Answer 2

嘗試

Toast.makeText( CreateEmailActivity.this,"Sending...",Toast.LENGTH_SHORT).show();

Answer 3

將getApplicationContext（）替換為上下文。

public class CreateEmailActivity extends AppCompatActivity {

    private Context context = CreateEmailActivity.this; //Add this

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

            Button send = findViewById(R.id.bntSendMail);

            send.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Toast.makeText(context,"Sending...",Toast.LENGTH_SHORT).show(); 
                }
            });
        }
        ...
        ...
    }