2022-10-16学习内容

1.Activity生命周期

1.1ActStartActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class ActStartActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String TAG = "ning";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "ActStartActivity onCreate");
        setContentView(R.layout.activity_act_start);
        findViewById(R.id.btn_act_next).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        startActivity(new Intent(this, ActFinishActivity.class));
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.d(TAG, "ActStartActivity onStart");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG, "ActStartActivity onResume");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "ActStartActivity onPause");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.d(TAG, "ActStartActivity onStop");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "ActStartActivity onDestroy");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.d(TAG, "ActStartActivity onRestart");
    }
}

1.2效果：

2022-10-16 08:09:13.762 5695-5695/com.example.chapter04 D/ning: ActStartActivity onCreate
2022-10-16 08:09:14.350 5695-5695/com.example.chapter04 D/ning: ActStartActivity onStart
2022-10-16 08:09:14.354 5695-5695/com.example.chapter04 D/ning: ActStartActivity onResume
2022-10-16 08:09:43.811 5695-5695/com.example.chapter04 D/ning: ActStartActivity onPause
2022-10-16 08:09:44.800 5695-5695/com.example.chapter04 D/ning: ActStartActivity onStop
2022-10-16 08:09:45.971 5695-5695/com.example.chapter04 D/ning: ActStartActivity onRestart
2022-10-16 08:09:45.981 5695-5695/com.example.chapter04 D/ning: ActStartActivity onStart
2022-10-16 08:09:45.991 5695-5695/com.example.chapter04 D/ning: ActStartActivity onResume

2.Activity启动模式

2.1activity_jump_first.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn_jump_second"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="跳到第二个页面" />

</LinearLayout>

2.2activity_jump_second.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn_jump_first"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="跳到第一个页面"/>

</LinearLayout>

2.3JumpFirstActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class JumpFirstActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_jump_first);
        findViewById(R.id.btn_jump_second).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // 创建一个意图对象，准备跳到指定的活动页面
        Intent intent = new Intent(this, JumpSecondActivity.class);
        // 栈中存在待跳转的活动实例时，则重新创建该活动的实例，并清除原实例上方的所有实例
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
    }
}

2.4JumpSecondActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class JumpSecondActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_jump_second);
        findViewById(R.id.btn_jump_first).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // 创建一个意图对象，准备跳到指定的活动页面
        Intent intent = new Intent(this, JumpFirstActivity.class);
        // 栈中存在待跳转的活动实例时，则重新创建该活动的实例，并清除原实例上方的所有实例
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
    }
}

2.5效果：

 2.6activity_login_input.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="这里是登陆验证页面，此处省略了用户名和密码等输入框"/>

    <Button
        android:id="@+id/btn_jump_success"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="跳转到登录成功页面"/>

</LinearLayout>

2.7activity_login_success.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="这里是登录成功页面，登陆成功后不必返回登录验证页面。请按返回键观察看看"/>

</LinearLayout>

2.8LoginInputActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class LoginInputActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login_input);
        findViewById(R.id.btn_jump_success).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // 创建一个意图对象，准备跳到指定的活动页面
        Intent intent = new Intent(this, LoginSuccessActivity.class);
        // 设置启动标志：跳转到新页面时，栈中的原有实例都被清空，同时开辟新任务的活动栈
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }
}

2.9效果：

 

3.显示Intent和隐式Intent

3.1ActStartActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class ActStartActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String TAG = "ning";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "ActStartActivity onCreate");
        setContentView(R.layout.activity_act_start);
        findViewById(R.id.btn_act_next).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // 1.在Intent的构造函数中指定
//        Intent intent = new Intent(this, ActFinishActivity.class);
        // 2.调用意图对象的setClass方法指定
        Intent intent = new Intent();
//        intent.setClass(this, ActFinishActivity.class);
        // 3.调用意图对象的setComponent方法指定
        ComponentName component = new ComponentName(this, ActFinishActivity.class);
        intent.setComponent(component);
        startActivity(intent);
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.d(TAG, "ActStartActivity onStart");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG, "ActStartActivity onResume");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "ActStartActivity onPause");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.d(TAG, "ActStartActivity onStop");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "ActStartActivity onDestroy");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.d(TAG, "ActStartActivity onRestart");
    }
}

3.2activity_action_uri.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:text="点击以下按钮将向号码12345发起请求"/>

    <Button
        android:id="@+id/btn_dial"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="跳到拨号页面" />

    <Button
        android:id="@+id/btn_sms"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="跳到短信页面" />

    <Button
        android:id="@+id/btn_my"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="跳到我的页面" />

</LinearLayout>

3.3ActionUriActivity.java

package com.example.chapter04;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;

public class ActionUriActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_action_uri);
        findViewById(R.id.btn_dial).setOnClickListener(this);
        findViewById(R.id.btn_sms).setOnClickListener(this);
        findViewById(R.id.btn_my).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Intent intent = new Intent();
        String phoneNo = "12345";
        switch (v.getId()) {
            case R.id.btn_dial:
                // 设置意图动作为准备拨号
                intent.setAction(Intent.ACTION_DIAL);
                // 声明一个拨号的Uri
                Uri uri = Uri.parse("tel:" + phoneNo);
                intent.setData(uri);
                startActivity(intent);
                break;

            case R.id.btn_sms:
                // 设置意图动作为发短信
                intent.setAction(Intent.ACTION_SENDTO);
                // 声明一个拨号的Uri
                Uri uri2 = Uri.parse("smsto:" + phoneNo);
                intent.setData(uri2);
                startActivity(intent);
                break;

            case R.id.btn_my:
                intent.setAction("android.intent.action.NING");
                intent.addCategory(Intent.CATEGORY_DEFAULT);
                startActivity(intent);
                break;
        }
    }
}

3.4charpter03/manifests/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.chapter03">

    <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.MyApplication">
        <activity
            android:name=".CalculatorActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

            <intent-filter>
                <action android:name="android.intent.action.NING" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>

</manifest>

3.5charpter04/manifests/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.chapter04">

    <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.MyApplication">
        <activity
            android:name=".LoginSuccessActivity"
            android:exported="false" />
        <activity
            android:name=".JumpSecondActivity"
            android:exported="false" />
        <activity
            android:name=".ActFinishActivity"
            android:exported="false" />
        <activity
            android:name=".ActionUriActivity"
            android:exported="true"
            android:launchMode="standard">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

3.6效果：