ANDROID笔记:Activity的显式和隐式调用

package com.example.android_activity.test;

import com.example.android_activity.R;

import android.app.LauncherActivity;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ArrayAdapter;

public class MyTestActivity extends LauncherActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                getApplicationContext(), android.R.layout.simple_list_item_1,
                new String[] { "com1", "com2" });
        setListAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // TODO Auto-generated method stub
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    protected Intent intentForPosition(int position) {
        // TODO Auto-generated method stub
        Intent intent = null;
        switch (position) {
        case 0:
            // 显式声明方式1
            intent = new Intent(MyTestActivity.this, CompActivity.class);
            // 显式声明方式2
            ComponentName componentName = new ComponentName(
                    MyTestActivity.this, CompActivity.class);
            intent.setComponent(componentName);
            // 显式声明方式3
            ComponentName componentName2 = new ComponentName(
                    "com.example.android_activity.test.MyTestActivity",
                    "com.example.android_activity.test.CompActivity");
            intent.setComponent(componentName);
            break;
        case 1:
            intent = new Intent();
            //隐式
            intent.setAction("com.ex.one");
            intent.addCategory("android.intent.category.DEFAULT");
            break;
        }
        return intent;

    }
}

隐式调用时需要在AndroidManifest.xml中配置该activity的action和category,

该方式可以使其他程序调用该程序的activity

 <activity
            android:name="com.example.android_activity.test.CompActivity"
            android:label="@string/app_name"
          
            android:exported="true"
             >
              <!-- android:exported="true" 其他程序可以调用  -->
            <intent-filter>
                <action android:name="com.ex.one" />
    
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>