点击事件，点击吐司（Toast），匿名内部类实现

本是古典何须时尚 2022-05-22 06:09 211阅读 0赞

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、

![70][]

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

[70]: /images/20220522/ff9d17f828ce4c88a77b60e00cfd0ff8.png