Question

当我将鼠标悬停在“setOnClickListener”下的红色线条上时，会弹出一条消息“无法解析符号setOnClickListener”，“@ Override”会显示“此处不允许使用注释”。来自“View v”的v也给了我一个错误。我在哪里陷入困境？

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

public class EmailReceiptActivity extends AppCompatActivity {


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

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main_options_menu, menu);
    menu.findItem(R.menu.main_options_menu).setIntent(
            new Intent(EmailReceiptActivity.this, LaunchActivity.class));
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    //use the id of the item from main_options_menu
    if (id == R.id.logoff_menu_item) {
        super.onOptionsItemSelected(item);
        startActivity(item.getIntent());
    }

    return true;
}

Button btn_send = (Button)findViewById(R.id.send_receipt_button);
btn_send.setOnClickListener(new View.OnClickListener(){
    @Override
    //Use the name of the function you assigned to the xml design of the button
    public void onClick(View v){
        //Use the name of this class, and the name class where you want to be taken when the button is clicked.
        startActivity (new Intent(EmailReceiptActivity.this, SuccessActivity.class));
    }
}

}

Answer 1

您应该将代码移至onCreate等方法中，以便设置onClickListener。您不能在函数体外执行类似的代码。另外，在Button之外宣布onCreate范围更广的范围可能更有用，所以请尝试...

public Button btn_send;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_email_receipt);

    btn_send = (Button)findViewById(R.id.send_receipt_button);
    btn_send.setOnClickListener(new View.OnClickListener(){
        @Override
        //Use the name of the function you assigned to the xml design of the   button
        public void onClick(View v){
            //Use the name of this class, and the name class where you want to be taken when the button is clicked.
            startActivity (new Intent(EmailReceiptActivity.this, SuccessActivity.class));
    }
}

Answer 2

如果您想将original_data.attachments.forEach(function(i) { var new_url = "https://example.com/" + i + ".png"; download(original_url, new_url, function(new_url){ console.log(new_url) new_data.new_url = new_url; save_new_url_to_mongodb(new_data); }); })放在外面，那么它应该是这样的：

OnClickListener

然后将其设置在OnClickListener sendListener = new View.OnClickListener(){ @Override //Use the name of the function you assigned to the xml design of the button public void onClick(View v){ //Use the name of this class, and the name class where you want to be taken when the button is clicked. startActivity (new Intent(EmailReceiptActivity.this, SuccessActivity.class)); } };

之类的区域

onCreate

但理想情况下，您希望将Button btn_send; protected void onCreate(Bundle savedInstanceState) { ... btn_send.setOnClickListener(sendListener); }和findViewById移动到OnClickListener

等区域

onCreate

Answer 3

私人按钮send_receipt_button;

public class GameOver extends AppCompatActivity implements View.OnClickListener {

 @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_email_receipt);
              Button btn_send = (ImageButton) findViewById(R.id.send_receipt_button);
             btn_send.setOnClickListener(this);

}

  public void onClick (View v){



            switch (v.getId()) {

                case R.id.send_receipt_button:
                     startActivity (new Intent(EmailReceiptActivity.this, SuccessActivity.class));


                    break;
}
}

我是我的setOnClickListener给我一个错误？

3 个答案: