Question

这是Android应用程序的Activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<ImageButton
    android:id="@+id/imageButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/sanzuup150"
    android:layout_gravity="center_horizontal" />
<ImageButton
    android:id="@+id/imageButton2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/sanzuuq150"
    android:layout_gravity="center_horizontal" />
<ImageButton
    android:id="@+id/imageButton3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/sanzuur150"
    android:layout_gravity="center_horizontal" />

</LinearLayout>

我对android开发很新，所以我不知道如何通过不同的url为imageButton2和imageButton3创建addListenerOnButton。请帮帮我......

这是MainActivity.java

package com.android.screation;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.widget.ImageButton;
import android.widget.Toast;
import android.view.View;
import android.view.View.OnClickListener;

public class MainActivity extends Activity {

ImageButton imageButton;

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

    addListenerOnButton();

}

public void addListenerOnButton() {

    imageButton = (ImageButton) findViewById(R.id.imageButton1);

    imageButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

        Intent browserIntent =
           new Intent(Intent.ACTION_VIEW,         Uri.parse("http://www.sanzuu.blogspot.com"));
            startActivity(browserIntent);

        }

    });

}

}

Answer 1

应该在每个imageButton上放置一个监听器。每个imageButton都是xml中的一个项目，然后应该（让我们说）使用id链接到java中。因此，同一个xml中的ID应该是唯一的。在使用之前始终将元素链接到xml中的引用，否则代码将为null指针异常。

package com.android.screation;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.widget.ImageButton;
import android.widget.Toast;
import android.view.View;
import android.view.View.OnClickListener;

public class MainActivity extends Activity {

ImageButton imageButton;
ImageButton imageButton2;
ImageButton imageButton3;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
imageButton = (ImageButton) findViewById(R.id.imageButton1); // refer to the id in the xml
imageButton2 = (ImageButton) findViewById(R.id.imageButton2);
imageButton3 = (ImageButton) findViewById(R.id.imageButton3);

//add the listener to the specific button
    imageButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
    Toast.makeText(getApplicationContext(), "This is button 1",
   Toast.LENGTH_LONG).show();
        Intent browserIntent =
           new Intent(Intent.ACTION_VIEW,         Uri.parse("http://www.sanzuu.blogspot.com"));
            startActivity(browserIntent);

        }

    });
imageButton2.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
//what imageButton2 is supposed to do
Toast.makeText(getApplicationContext(), "This is button 2",Toast.LENGTH_LONG).show();
        }

    });
imageButton3.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

       // what imageButton3 is supposed to do here
Toast.makeText(getApplicationContext(), "This is button 3",Toast.LENGTH_LONG).show();

        }

    });

}

}

如果您需要更多帮助，请随时提出。

如何在android studio中添加多个addListenerOnButton

1 个答案: