如何在android studio中添加按钮点击事件 [英] how to add button click event in android studio

问题描述

所以我做了一些研究，在通过代码将你的按钮定义为一个对象之后

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) ;

这是我的问题

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

然后你的 OnClick() 事件...

then your OnClick() event...

问题:

当我输入this"时，它说:

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

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

我不知道为什么?

这里是 .java 文件中的代码

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;

    }

推荐答案

View 中的 SetOnClickListener (Android.View.view.OnClickListener) 不能应用于 (com.helloandroidstudio.MainActivity)

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

换句话说(由于您当前的情况)您的 MainActivity 需要实现 OnClickListener:

This means in other words (due to your current scenario) that your MainActivity need to implement OnClickListener:

public class Main extends ActionBarActivity implements View.OnClickListener {
   // do your stuff
}

这个:

buttonname.setOnClickListener(this);

意味着你想为你的按钮分配侦听器在这个实例上" ->这个实例代表OnClickListener，因此您的类必须实现该接口.

means that you want to assign listener for your Button "on this instance" -> this instance represents OnClickListener and for this reason your class have to implement that interface.

它类似于匿名侦听器类(您也可以使用):

It's similar with anonymous listener class (that you can also use):

buttonname.setOnClickListener(new View.OnClickListener() {

   @Override
   public void onClick(View view) {

   }
});

这篇关于如何在android studio中添加按钮点击事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！