点击事件，点击吐司（Toast），匿名内部类实现

版权声明：https://blog.csdn.net/qq_40881680 https://blog.csdn.net/qq_40881680/article/details/80719060

1、按钮点击事件

      当点击按钮后出现效果或结果就是点击事件，首先先看效果图，点击后吐司在屏幕上、

        

     代码如下：

        xml:

        

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn"
        android:layout_width="100dp"
        android:layout_height="40dp"
        android:text="点击"
        />

</android.support.constraint.ConstraintLayout>

       Java:

package com.example.zy.mystudy;

import android.app.Activity;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
    private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        button = (Button)findViewById(R.id.btn);
        button.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Toast.makeText(MainActivity.this, "匿名内部类方式", Toast.LENGTH_SHORT).show();
                    }
                }

        );
    }
}

这样是通过了匿名内部类方式实现了点击按钮吐司

=====================================================================

同时，你也可以这样写：

xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical"
    >

    <Button
        android:id="@+id/btn1"
        android:layout_width="100dp"
        android:layout_height="40dp"
        android:text="点击1"
        />
    <Button
        android:id="@+id/btn2"
        android:layout_width="100dp"
        android:layout_height="40dp"
        android:text="点击2"
        />

</LinearLayout>

Java:

package com.example.zy.mystudy;

import android.app.Activity;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
    private Button button1;
    private Button button2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        button1 = (Button)findViewById(R.id.btn1);
        button1.setOnClickListener(onClickListener);

        button2 = (Button)findViewById(R.id.btn2);
        button2.setOnClickListener(onClickListener);
    }
    View.OnClickListener onClickListener = new View.OnClickListener(){
        @Override
        public void onClick(View view) {
            switch (view.getId()){
                case R.id.btn1:
                    Toast.makeText(MainActivity.this,"点击事件1",Toast.LENGTH_SHORT).show();
                    break;
                case R.id.btn2:
                    Toast.makeText(MainActivity.this,"点击事件2",Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    };
}

这样写可以避免在创建时多次占用资源