how to add button click event in android studio

2019-03-09 15:49发布

So I have done some research, and after defining you button as an object by the code

private Button buttonname;
buttonname = (Button) findViewById(R.id.buttonnameinandroid) ;

here is my problem

buttonname.setOnClickListener(this); //as I understand it, the "**this**" denotes the current `view(focus)` in the android program

then your OnClick() event...

Problem:

When I type in the "this", it says:

setOnClickListener (Android.View.view.OnClickListener) in View cannot be applied to (com.helloandroidstudio.MainActivity)

I have no idea why?

here is the code from the .java file

import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    private Button btnClick;
    private EditText Name, Date;
    private TextView msg, NameOut, DateOut;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnClick = (Button) findViewById(R.id.button) ;
        btnClick.setOnClickListener(this);
        Name = (EditText) findViewById(R.id.textenter) ;
        Date = (EditText) findViewById(R.id.editText) ;
        msg = (TextView) findViewById(R.id.txtviewOut) ;
        NameOut = (TextView) findViewById(R.id.txtoutName) ;
        DateOut = (TextView) findViewById(R.id.txtOutDate) ;
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    public void onClick(View v)
    {
        if (v == btnClick)
        {
            if (Name.equals("") == false && Date.equals("") == false)
            {
                NameOut = Name;
                DateOut = Date;
                msg.setVisibility(View.VISIBLE);
            }
            else
            {
                msg.setText("Please complete both fields");
                msg.setVisibility(View.VISIBLE);
            }
        }
        return;

    }

13条回答
来,给爷笑一个
2楼-- · 2019-03-09 16:32

Different ways to handle button event

Button btn1 = (Button)findViewById(R.id.button1);
btn1.setOnClickListener(new View.OnClickListener() {            
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Toast.makeText(context, "Button 1", 
     Toast.LENGTH_LONG).show();
        }
    });

[Check this article for more details about button event handlers]

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