Android Studio小笔记(3) - Activity

FirstActivity:

public class FirstActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.first_layout);
        Button button1 = (Button)findViewById(R.id.button_1);
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String data = "你好呀，第二个活动";
                //Toast.makeText(FirstActivity.this,"请给我点赞哟!!!", Toast.LENGTH_SHORT).show(); //弹出信息
                Intent intent = new Intent(FirstActivity.this, SecondActivity.class);   //显示调用另外的一个Activity，例如SecondActivity
                //Intent intent = new Intent("android.example.activitytest.Action_START");  //隐式调用另外的一个Activity，例如SecondActivity
                //Intent intent = new Intent(Intent.ACTION_VIEW); //显示用户数据,会根据用户的意图打开相应的Activity
                //intent.setData(Uri.parse("http://baidu.com"));  //调用浏览器打开网址
                //intent.setData(Uri.parse("tel:10086")); //调用拨号程式拨打10086
                intent.putExtra("extra_data", data);    //通过键“extra_data”传递数据data到第二个活动页
                startActivity(intent);
            }
        });
    }
    public boolean onCreateOptionsMenu(Menu menu){
        getMenuInflater().inflate(R.menu.main,menu);
        return true;
    }
    public boolean onOptionsItemSelected(MenuItem item){
        switch (item.getItemId()){
            case R.id.add_item1:
                Toast.makeText(FirstActivity.this,"我可以给你添加一个item", Toast.LENGTH_SHORT).show();
                break;
            case R.id.remove_item:
                Toast.makeText(FirstActivity.this,"你想删除那个item", Toast.LENGTH_SHORT).show();
                break;
            default:
                break;
        }
        return true;
    }
}

SecondActivity:

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        Intent intent = getIntent();    //定义一个获取intent
        String data = intent.getStringExtra("extra_data");  //通过键“extra_data”,获取第一个活动要传递过来的值
        Log.d("SecondActivity", data);  //在Logcat中显示data信息
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.activity">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Activity">
        <activity android:name=".SecondActivity">
            <intent-filter>
                <action android:name="android.example.activitytest.Action_START"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </activity>
        <activity
            android:name=".FirstActivity"
            android:label="这是第一个活动页">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>