android点击事件

MainActivity.java

package com.example.tmftest;

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 AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //        隐藏标题栏
        if (getSupportActionBar() != null) {
            getSupportActionBar().hide();
        }

        setContentView(R.layout.activity_main);

        Button btn1 = findViewById(R.id.btn_menu);
        Button btn2 = findViewById(R.id.btn_calendar);
        Button btn3 = findViewById(R.id.btn_maintenance);

        btn1.setOnClickListener(MainActivity.this);
        btn2.setOnClickListener(MainActivity.this);
        btn3.setOnClickListener(MainActivity.this);

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_menu:
                Toast.makeText(MainActivity.this, "btn_menu", Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn_calendar:
                Toast.makeText(MainActivity.this, "btn_calendar", Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn_maintenance:
                Toast.makeText(MainActivity.this, "btn_maintenance", Toast.LENGTH_SHORT).show();
                break;
            default:
                break;
        }
    }

}

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">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="20dp">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:orientation="horizontal">
            <Button
                android:id="@+id/btn_menu"
                android:layout_width="0dp"
                android:layout_height="150dp"
                android:layout_margin="10dp"
                android:layout_weight="1"
                android:text="菜品维护"
                />
            <Button
                android:id="@+id/btn_calendar"
                android:layout_width="0dp"
                android:layout_height="150dp"
                android:layout_margin="10dp"
                android:layout_weight="1"
                android:text="菜单日历"
                />

        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:orientation="horizontal">
            <Button
                android:id="@+id/btn_maintenance"
                android:layout_width="0dp"
                android:layout_height="150dp"
                android:layout_margin="10dp"
                android:layout_weight="1"
                android:text="参数维护"
                />
            <Button
                android:id="@+id/btn_add"
                android:layout_width="0dp"
                android:layout_height="150dp"
                android:layout_margin="10dp"
                android:layout_weight="1"
                android:text="+"
                />

        </LinearLayout>
    </LinearLayout>

</android.support.constraint.ConstraintLayout>