Activity概述

Activity的响应事件

Activity之间的数据传递

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <TextView
        android:id="@+id/tv1"
        android:textSize="20sp"
        android:text="第一个activity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/btn1"
        android:text="启动第二个activity"
        android:onClick="btnClick1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/btn2"
        android:text="启动第二个activity-传数据1"
        android:onClick="btnClick2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/btn3"
        android:text="启动第二个activity-传数据2"
        android:onClick="btnClick3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/btn4"
        android:text="启动第二个activity-传回数据1"
        android:onClick="btnClick4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

activity_main2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Main2Activity">
    <TextView
        android:id="@+id/tv1"
        android:textSize="20sp"
        android:text="第二个activity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/tv2"
        android:textSize="20sp"
        android:text="传递的数据："
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/btn1"
        android:textSize="20sp"
        android:text="返回"
        android:onClick="btnRet"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

MainActivity.java

package com.bluelesson.activitydemo;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        Log.d("15pb","onKeyUp");
        return super.onKeyUp(keyCode, event);
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        Log.d("15pb","onKeyDown");
        return super.onKeyDown(keyCode, event);
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        Log.d("15pb","onTouchEvent");
        return super.onTouchEvent(event);
    }
    public void btnClick1(View view) {
        // 1. 创建Intent对象
        Intent intent = new Intent();
        // 2. 设置信息
        intent.setClass(this,
                Main2Activity.class
                );
        // 3. 启动activity
        startActivity(intent);
    }
    public void btnClick2(View view) {
        // 1. 创建Intent对象
        Intent intent = new Intent();
        // 2. 设置信息
        // 2.1 设置类类型
        intent.setClass(this,
                Main2Activity.class
        );
        // 2.2 设置传递的数据
        intent.putExtra("name","hello");
        // 3. 启动activity
        startActivity(intent);
    }
    public void btnClick3(View view) {
        // 1. 创建Intent对象
        Intent intent = new Intent();
        // 2. 设置信息
        // 2.1 设置类类型
        intent.setClass(this,
                Main2Activity.class
        );
        // 2.2 设置传递的数据
        Bundle bundle = new Bundle();
        bundle.putString("name","hello15pb");
        intent.putExtras(bundle);
        // 3. 启动activity
        startActivity(intent);
    }
    public void btnClick4(View view) {
        // 1. 创建Intent对象
        Intent intent = new Intent();
        // 2. 设置信息
        intent.setClass(this,
                Main2Activity.class
        );
        // 3. 启动activity
        // 传入请求码
        startActivityForResult(intent,0x111);
    }
    @Override
    protected void onActivityResult(int requestCode,
                                    int resultCode,
                                    Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode == 0x111){
            String name = data.getStringExtra("name");
            Toast.makeText(this,
                    "传回的数据："+name,
                    Toast.LENGTH_SHORT).show();
        }
    }
}

Main2Activity.java

package com.bluelesson.activitydemo;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
public class Main2Activity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        // 接收数据
        Intent intent = getIntent();
        String name = intent.getStringExtra("name");
        if(name == null){
            Bundle bundle = intent.getExtras();
            if(bundle != null){
                name = bundle.getString("name");
            }
        }
        // 显示数据
        TextView textView = findViewById(R.id.tv2);
        textView.setText("传递的数据："+name);
    }
    public void btnRet(View view) {
        // 返回时，可以设置数据
//        setResult(0x111);
        Intent intent = new Intent();
        intent.putExtra("name","hi hello");
        setResult(0x111,intent);
        finish();//关闭activity
    }
}

Activity的intent隐式启动

隐式启动

隐式启动设置data