Android activity创建三部曲

1.新建类继承Activity或其子类，现在一般继承AppCompatActivity

public class TestActivity extends AppCompatActivity {    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_test);    }}

2.在AndroidManifest文件中声明这个activity

<activity android:name=".TestActivity"></activity>

3.创建layout布局文件并在activity中的onCreate中设置

public class TestActivity extends AppCompatActivity {    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_test);    }}

在AndroidManifest中设置启动activity

<activity android:name=".HelloWorldActivity"    android:label="lidahua"    >    <intent-filter>        <action android:name="android.intent.action.MAIN" />        <category android:name="android.intent.category.LAUNCHER" />    </intent-filter></activity>

不适用系统自带的titlebar

    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:supportsRtl="true"        android:theme="@style/Theme.AppCompat.Light.NoActionBar">        <activity android:name=".HelloWorldActivity"            android:label="lidahua"  --给titlebar重新设置标题            >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity android:name=".TestActivity">        </activity>    </application>

</manifest>

原文地址：https://www.cnblogs.com/AppTester/p/9937679.html