Android：按下了哪个按钮

Question

I found the following solution for detecting which of my buttons was pressed:

public void onClick(View v) {
    switch(v.getId())
    {
    case R.id.bteins:
    Toast t = Toast.makeText(this, "bzeins", Toast.LENGTH_SHORT);
    t.show();
    break;
    case R.id.btzwei:
    // handle button B click;
    break;
    case R.id.btdrei:
        Toast t1 = Toast.makeText(this, "btdfrei", Toast.LENGTH_SHORT);
        t1.show();
    break;
    case R.id.btvier:
    // handle button B click;
    break;
    default:
    throw new RuntimeException("Unknow button ID");
    }
    }

My problem is that when I press bteins or btdrei nothing happens. What´s my mistake?

Answer 1

you can implement onClick for each button like this:

    findViewById(R.id.bteins).setOnClickListener(new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            //do some things!
        }
    });
    findViewById(R.id.btzwei).setOnClickListener(new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            //do some things!
        }
    });
....

or implement OnClickListener in activity and set all buttons click to that:

public class Test extends Activity implements OnClickListener
{
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);

        findViewById(R.id.bteins).setOnClickListener(this);
        findViewById(R.id.btzwei).setOnClickListener(this);
        findViewById(R.id.btdrei).setOnClickListener(this);
        findViewById(R.id.btvier).setOnClickListener(this);
    }

    @Override
    public void onClick(View v)
    {
        switch(v.getId())
            {
            case R.id.bteins:
                Toast t = Toast.makeText(this, "bzeins", Toast.LENGTH_SHORT);
                t.show();
                break;
            case R.id.btzwei:
                // handle button B click;
                break;
            case R.id.btdrei:
                    Toast t1 = Toast.makeText(this, "btdfrei", Toast.LENGTH_SHORT);
                    t1.show();
                break;
            case R.id.btvier:
                // handle button B click;
                break;
            default:
                throw new RuntimeException("Unknow button ID");
            }
    }
}

Answer 2

Have you set OnClickListener to the button? I guess you haven't.

Answer 3

public class theexample extends Activity implements OnClickListener

//OnCreateEvent
bteins.setOnClickListener(this);
btvier.setOnClickListener(this);

public void OnClick(View v){
switch(v.getId()){
            case R.id.bteins:
                Toast.makeText(this, "bzeins", Toast.LENGTH_SHORT).show();
                t.show();
                break;
            case R.id.btzwei:
                // handle button B click;
                break;
            case R.id.btdrei:
                   Toast.makeText(this, "btdfrei", Toast.LENGTH_SHORT).show();
                break;
            case R.id.btvier:
                // handle button B click;
                break;
            default:
                throw new RuntimeException("Unknow button ID");
            }
    }

Answer 4

You need to connect triggers to their respective handlers with setOnClickListener()

This method either gets this as a parameter, and than your activity has to implement OnClickListener (Eclipse can help you auto refactor these things easily.)

Or, just pass it a new OnClickListener on the spot:

Button myButton = (Button) findViewById(*buttons id*);
myButton.setOnClickListener(new OnClickListener()
{
    @Override
    public void onClick(View v)
    {
        //You can check v attributes to see what was clicked as well. 
    }
});