Activity显式启动-Activity隐式启动

Activity的启动方法

显式启动:
明确指定要启动的Activity的class或者包名.activity类名

方式一:class跳转
Intent intent = new Intent(Activity1.this,Activity2.class);
startActivity(intent);

方式二:包名.类名跳转
Intent intent = new Intent();
intent.setClassName(context,“com.maizi.lasson.activitylasson1”);
startActivity(intent);

方式三:ComponentName跳转
Intent intent = new Intent();
intent.setComponent(new Component(context,Activity2.class))
startActivity(intent);

隐式启动:
设置启动过滤器，通过指定的action或action和data属性，系统会查找符合条 件的activity，并启动它

方式一:构造时传入actionName
Intent intent = new Intent(“com.maizi.lasson.SecondActivity”);
startActivity(intent);

方式二:构造完成后设置actionName
Intent intent = new Intent();
intent.setAction(“com.maizi.lasson.SecondActivity”);
startActivity(intent);

注意:如果自己定义的某个Activity要通过隐式启动，在AndroidManifest.xml那么必须加上android.intent.category.DEFAULT，否则不起作用

关闭Activitiy:调用finish();

package com.maizi.lesson.activity.activitylesson1;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MyActivity extends Activity{

Button btnStart;

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

    btnStart = (Button) findViewById(R.id.btn_start_second);
    btnStart.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v){
            //在这里启动第二个Activity

            //显式启动的第一种写法
            Intent intent = new Intent();
            intent.setClass(MainActivity.this,SecondActivity.class);

            startActivity(intent);

            //显式启动的第二种写法
            Intent intent1 = new Intent();
            intent.setClass(MainActivity.this,"com.maizi.lesson.activity.SecondActivity");

            startActivity(intent1);

            //显式启动的第三种写法
            Intent intent1 = new Intent();
            ComponentName componentName = new ComponentName(MainActivity.this,SecondActivity.class);
            intent.setComponent(componentName);
            startActivity(intent);

            //隐式启动的第一种写法
            Intent intent = new Intent("abcd.SecondActivity");
            startActivity(intent);

            //隐式启动的第二种写法
            Intent intent = new Intent();
            intent.setAction("abcd.SecondActivity");
            startActivity(intent);
        }
    });
}

}

package com.maizi.lesson.activity.activitylesson1;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MyActivity extends Activity{

Button btnStart;

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

    btnStart = (Button) findViewById(R.id.btn_start_second);
    btnStart.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v){
            //在这里启动第二个Activity

            //显式启动的第一种写法
            Intent intent = new Intent();
            intent.setClass(MainActivity.this,SecondActivity.class);

            startActivity(intent);

            //显式启动的第二种写法
            Intent intent1 = new Intent();
            intent.setClass(MainActivity.this,"com.maizi.lesson.activity.SecondActivity");

            startActivity(intent1);

            //显式启动的第三种写法
            Intent intent1 = new Intent();
            ComponentName componentName = new ComponentName(MainActivity.this,SecondActivity.class);
            intent.setComponent(componentName);
            startActivity(intent);

            //隐式启动的第一种写法
            Intent intent = new Intent("abcd.SecondActivity");
            startActivity(intent);

            //隐式启动的第二种写法
            Intent intent = new Intent();
            intent.setAction("abcd.SecondActivity");
            startActivity(intent);
        }
    });
}

}

package com.maizi.lesson.activity.activitylesson1;

import android.app.Activity;
import android.os.Bundle;

public class SecondActivity extends Activity{

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

    Button bthFinish = (Button) findViewById(R.id.bth_finish_self);
    bthFinish.setOnClickListener(){
        @Override
        public void onClick(View v){
            //关闭自己 SecondActivity

            SecondActivity.this.finish();
        }
    });
}

}

<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”

<TextView
android:layout_width=“wrap_content”

android:layout_height="wrap_content"
android:text="这是第二个界面"/>

<Button
android:id="@+id/btn_finish_self"
android:layout_width="wrap_content"
  
android:layout_height="wrap_content"
android:text="关闭"/>

<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”

<Button
android:id="@+id/btn_start_second"
android:layout_width=“wrap_content”

android:layout_height="wrap_content"
android:text="启动第二个界面"/>