如何在一个活动中具有多个按钮

Question

My Android app having many buttons.

My main.xml layout has three buttons.

I know how to use buttons to go from one activity to another, But i don't know how to have multiple buttons on one activity, with each launching a different activity than the other.

EXAMPLE

Main.xml

Button1 Button2

Main2.xml

Launched by button1

About.xml

Launched by Button2

How do i make the main.java file do this?

Answer 1

public class NL extends Activity {



     public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
          Button b1=(Button)findViewById(R.id.Button01);
          Button b2=(Button)findViewById(R.id.Button02);
          b1.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                Intent myintent2 = new Intent(NL.this,Button1.class);
                startActivity(myintent2);

            }
        });
          b2.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {
                    Intent myintent2 = new Intent(NL.this,Button2.class);
                    startActivity(myintent2);

                }
            }); 
    }
}

move from one activity to another activity using intent.we write that code in button click listener

Answer 2

This is a pretty broad question, so my answer will probably seem equally broad.

1.) The first thing to understand is how to build your layout. You say you have a layout with 3 buttons already. Within the definition for each one of those buttons you need to assign an android:id attribute. This is what will allow you to later hook into that button from your Activity. For more information see here

2.) Once you have your 3 buttons defined with android:id's (lets use R.id.1 , R.id.2 and R.id.3 for sake of discussion) you'd want to hook Java objects to these elements in your Activities onCreate method:

Button button3 = (Button) getViewById(R.id.3)

Do this for your 3 buttons.

3.) The next step is to attach an onClick listener to your buttons

button3.setOnClickListener(new OnClickListener(){
  public void onClick(View v){
    //place code to execute here
  }
});

As with most gui frameworks in java, this mechanism defines the code that is executed when your button is clicked. If you want to launch a new Activity from this button, you would create an intent object and launch it like:

Intent intent = new Intent(this, TheActivityClassYouWantToLaunch.class);
startActivity(intent);

Replace TheActivityClassYouWantToLaunch with the name of the class which extends Activity that you want to launch. To learn more [check out the documentation on Intents] ( http://developer.android.com/reference/android/content/Intent.html )

Answer 3

I know this has long since been answered, but if anyone else stumbles across it, I figured I would provide another way to do buttons that I am using for my own code is by using the onClick and View. onclick is done in the xml file by going down to the button you want to make click-able and adding the line:

    android:onClick="title"

Where title is the name of the part of the java activity class file that goes with that xml file. Over in the java file you'll then add into the public class:

public void title(View buttonName) {
    // Should take user to the next view when button pressed
    Intent intent1 = new Intent(this, NextClass.class);
    startActivity(intent1);
}

Where buttonName is the name of the button that you added the onClick part to and NextClass is the name of the java file you wish to access. For your examples, in your Main.xml you would go down to button1 and add the onClick code then go over to Main.java and add the public void code, changing title to what ever you want, such as launchMain2. In that same .java you would change NextClass.class to Main2.class.

I use this because I find it easy to just copy and past it since i have multiple pages with just a few buttons on each page of my app. Thus for me, this helped me save time on working on the app.

Answer 4

i use this code
     ImageButton bot1;
 ImageButton bot2;
 ImageButton bot3;
 ImageButton bot4;
 Intent intentbot1; 
 Intent intentbot2;
     Intent intentbot3;
     Intent intentbot4;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.currentactivity);
    bot1= (ImageButton)findViewById(R.id.bot1);
    bot2 = (ImageButton)findViewById(R.id.bot2);
    bot3 = (ImageButton)findViewById(R.id.bot3);
    bot4 = (ImageButton)findViewById(R.id.bot4);


{   final Intent intentbot1 = new Intent();
      intentbot1.setClass(currentactivity.this, targetactivity.class);
    bot1.setOnClickListener(new OnClickListener() {
     public void onClick(View v) {
         startActivity(intentbot1);
            }});}
{
     final Intent intentbot2 = new Intent();
      intentbot2 .setClass(currentactivity.this, targetactivity.class);
    bot2.setOnClickListener(new OnClickListener() {
     public void onClick(View v) {
         startActivity(intentbot2 );
            }});}

{ final Intent intentbot3 = new Intent();
 intentbot3 .setClass(currentactivity.this, targetactivity.class);
bot3.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
 startActivity(intentbot3 );
       }});
    }
{ final Intent intentbot4 = new Intent();
intentbot4 .setClass(currentactivity.this, targetactivity.class);
bot4.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
 startActivity(intentbot4 );
      }});
    }
}