Question

我是android和java的新手但是我不明白如何实现这个方法，而不是当我点击应用程序中的按钮时它是一个错误。这是代码

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends Activity {


    public TextView theQuestion;

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

        theQuestion = (TextView) findViewById(R.id.Title);

    }//end of onCreate


    public void action(View theQuestion){
        theQuestion.setVisibility(View.VISIBLE);
    }

    public void antiAction(View theQuestion){
        theQuestion.setVisibility(View.INVISIBLE);
    }

}//the end
<Button
    style="?android:attr/buttonStyleSmall"
    android:onClick="action"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Go"
    android:id="@+id/button1" />
<Button
    style="?android:attr/buttonStyleSmall"
    android:onClick="antiAction"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="undo"
    android:id="@+id/button2" />

和xml代码

请帮帮我

Answer 1

你必须按下按钮，

  Button button = (Button) findViewById(R.id.button_id);

 button.setOnClickListener(new View.OnClickListener() {
         public void onClick(View v) {
             // Perform action on click
         }
     });

或转到res - layout - main.xml并在按钮中键入此内容机器人：的onClick =＆＃34;按钮＆＃34;

并取名为

public void button (view v ) 
{
type your code 
}

Answer 2

只需在布局XML中的Button上添加onClick="action"。

要点击按钮，有两种类型 1.在布局XML中添加onClick =“action” 然后在Java文件中定义动作mathod

public void action(View view){
//where view define this button define in xml
// Perform action on click
}

初始化按钮后，添加onCLickListener

按钮按钮=（按钮）findViewById（R.id.button_id）;

             button.setOnClickListener(new View.OnClickListener() {
                 public void onClick(View v) {
                 }
             });

Answer 3

以上都没有奏效，但确实如此 import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.TextView;

public class MainActivity extends Activity {

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

    }//end of onCreate


    public void action(View view){
        TextView theQuestion = (TextView) findViewById(R.id.Title);
        theQuestion.setVisibility(View.VISIBLE);
    }

    public void antiAction(View view){
        TextView theQuestion = (TextView) findViewById(R.id.Title);
        theQuestion.setVisibility(View.INVISIBLE);
    }


}//the end

找不到方法查看错误

3 个答案: