Android的相关事件

1.Toast信息提醒

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;

public class FirstActivity extends AppCompatActivity {

    private static final String TAG = "FirstActivity";

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.first_layout);

// 获取按钮

        Button button1 = (Button) findViewById(R.id.button_1);

//点击事件

        button1.setOnClickListener(new View.OnClickListener(){

            @Override

            public void onClick(View v) {

//  弹出信息

                Toast.makeText(FirstActivity.this,"You click button1",

                Toast.LENGTH_SHORT).show();

            }

        });

    }

}

2.在活动中使用Menu

res下新建一个Director,名为menu,在menu中建一个main的menuresourceFile(右键新建即可)

main.xml:

<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item

        android:id="@+id/add_item"

        android:title="Add" />

    <item

        android:id="@+id/remove_item"

        android:title="Remove" />

</menu>

FirstActivity.java

package com.example.activitytest;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.util.Log;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;

public class FirstActivity extends AppCompatActivity {

    private static final String TAG = "FirstActivity";

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.first_layout);

        //获取按钮

        Button button1 = (Button) findViewById(R.id.button_1);

        //点击事件

        button1.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                //弹出信息

                Toast.makeText(FirstActivity.this, "You click button1",

                        Toast.LENGTH_SHORT).show();

            }

        });

    }

    //定义菜单的选项

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

    //定义菜单选项的点击事件

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {

            case R.id.add_item:

                Toast.makeText(this, "点击了add", Toast.LENGTH_LONG).show();

                break;

            case R.id.remove_item:

                Toast.makeText(this, "点击了remove", Toast.LENGTH_LONG).show();

                break;

            default:

        }

        return true;

    }

}

3.销毁一个活动

一般我们点击Back按钮可以实现返回的效果,如果需要自定义销毁可以调用finish()方法

 @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.first_layout);

        //获取按钮

        Button button1 = (Button) findViewById(R.id.button_1);

        //点击事件

        button1.setOnClickListener(new View.OnClickListener() {

            @Override

            //销毁一个活动

            public void onClick(View v) {

                //销毁 和Back键的效果是一样的

                finish();

            }

        });

    }