Android基礎------Activity基礎

應用內Activity的跳轉方式

一、通過顯式意圖跳轉，如字面意思一樣，跳轉的目的地是可以明確看到的

二、通過隱式意圖跳轉，這種方式的跳轉需要我們在AndroidManifest.xml文件中爲目的Activity配置Action和Category

模擬賬號登錄，分別使用倆種方式跳轉

這是啓動的Activity

package com.example.myapplication.intentinner;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.myapplication.R;

/**
 * 應用內通過顯式和隱式跳轉
 */
public class SendMessageActivity extends AppCompatActivity {

    private Button buttonShow;
    private Button buttonHide;
    private EditText editTextAccount;
    private EditText editTextPassword;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initListener();
    }

    /**
     * 初始化UI
     */
    private void initView() {
        buttonShow = findViewById(R.id.btn_send_show);
        buttonHide = findViewById(R.id.btn_send_hide);
        editTextAccount = findViewById(R.id.edit_text_account);
        editTextPassword = findViewById(R.id.edit_text_password);
    }

    /**
     * 設置監聽事件
     */
    private void initListener() {
         //通過顯式意圖跳轉
        buttonShow.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(SendMessageActivity.this, ReceiverShowActivity.class);
                String account = editTextAccount.getText().toString().trim();
                if(TextUtils.isEmpty(account)){
                    Toast.makeText(SendMessageActivity.this,"賬號不能爲空",Toast.LENGTH_SHORT).show();
                    return;
                }
                String password = editTextPassword.getText().toString().trim();
                if(TextUtils.isEmpty(password)){
                    Toast.makeText(SendMessageActivity.this,"密碼不能爲空",Toast.LENGTH_SHORT).show();
                    return;
                }
                intent.putExtra("account",account);
                intent.putExtra("password",password);
                startActivity(intent);
            }
        });

        //通過隱式意圖跳轉，需要添加action和category，在AndroidManifest.xml文件對應的Activity中查看
        buttonHide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setAction("com.example.myapplication.LOGIN");
                intent.addCategory(Intent.CATEGORY_DEFAULT);
                String account = editTextAccount.getText().toString().trim();
                if(TextUtils.isEmpty(account)){
                    Toast.makeText(SendMessageActivity.this,"賬號不能爲空",Toast.LENGTH_SHORT).show();
                    return;
                }
                String password = editTextPassword.getText().toString().trim();
                if(TextUtils.isEmpty(password)){
                    Toast.makeText(SendMessageActivity.this,"密碼不能爲空",Toast.LENGTH_SHORT).show();
                    return;
                }
                intent.putExtra("account",account);
                intent.putExtra("password",password);
                startActivity(intent);
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    android:orientation="vertical"
    tools:context=".intentinner.SendMessageActivity">

    <EditText
        android:id="@+id/edit_text_account"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:maxLines="1"
        android:maxLength="16"
        android:inputType="text"
        android:digits="qwertyuiopasdfghjklzxcvbnm."
        android:layout_marginTop="10dp"/>

    <EditText
        android:id="@+id/edit_text_password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:maxLines="1"
        android:maxLength="20"
        android:inputType="textPassword"
        android:digits="1234567890."
        android:layout_marginTop="10dp"/>

    <Button
        android:id="@+id/btn_send_show"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="顯式意圖跳轉"
        android:textSize="20sp"
        android:layout_marginTop="10dp"/>

    <Button
        android:id="@+id/btn_send_hide"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="隱式意圖跳轉"
        android:textSize="20sp"
        android:layout_marginTop="10dp"/>



</LinearLayout>

下面是顯示意圖的目的Activity

package com.example.myapplication.intentinner;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
import androidx.annotation.Nullable;

import com.example.myapplication.R;

/**
 * 顯示意圖接收
 */
public class ReceiverShowActivity extends Activity {

    private TextView textView;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_receiver_show);
        //通過getIntent()方法獲取傳過來Intent
        Intent intent = getIntent();
        String account = intent.getStringExtra("account");
        String password = intent.getStringExtra("password");
        textView = findViewById(R.id.text_view_show_result);
        textView.setText("賬號爲："+account+"，密碼爲："+password);
    }
}

<?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:padding="10dp"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="登錄成功"
        android:textColor="@color/colorAccent"
        android:textSize="20sp"
        android:gravity="center"/>

    <TextView
        android:id="@+id/text_view_show_result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="15sp"
        android:textColor="@color/colorPrimaryDark"
        android:layout_marginTop="15dp"/>
</LinearLayout>

下面是隱式意圖的目的Activity

package com.example.myapplication.intentinner;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

import com.example.myapplication.R;

/**
 * 隱示意圖接收
 */
public class ReceiverHideActivity extends AppCompatActivity {

    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_receiver_hide);
        //通過getIntent()方法獲取傳過來Intent
        Intent intent = getIntent();
        String account = intent.getStringExtra("account");
        String password = intent.getStringExtra("password");
        textView = findViewById(R.id.text_view_hide_result);
        textView.setText("賬號爲："+account+"，密碼爲："+password);
    }
}

<?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:padding="10dp"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="登錄成功"
        android:textColor="@color/colorAccent"
        android:textSize="20sp"
        android:gravity="center"/>

    <TextView
        android:id="@+id/text_view_hide_result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="15sp"
        android:textColor="@color/colorPrimaryDark"
        android:layout_marginTop="15dp"/>
</LinearLayout>

跳轉到第三方應用，例如手機的瀏覽器，電話

打開手機的瀏覽器

package com.example.myapplication.intentout;

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

import androidx.annotation.Nullable;

import com.example.myapplication.R;

public class ThirdActivity extends Activity {

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

    /**
     * 顯式意圖跳轉手機瀏覽器
     * @param view
     */
    public void skipShowIntent(View view){
        Intent intent = new Intent();
        //這裏舉個例子，因爲不同機型的瀏覽器包名可能不同，請根據具體情況而定
        intent.setClassName("com.android.browser","com.android.browser.BrowserActivity");
        startActivity(intent);
    }

    /**
     * 隱式意圖跳轉手機瀏覽器
     * @param view
     */
    public void skipHideIntent(View view){
        Intent intent = new Intent();
        //這裏舉個例子，Action、Category和Package視情況而定
        intent.setAction("android.intent.action.VIEW");
        intent.addCategory(Intent.CATEGORY_DEFAULT);
        startActivity(intent);
    }
}

<?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:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="顯式意圖跳轉"
        android:onClick="skipShowIntent"
        android:textSize="20sp"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="隱式意圖跳轉"
        android:onClick="skipHideIntent"
        android:textSize="20sp"/>

</LinearLayout>

跳轉後獲取數據返回

在第二個界面輸入內容後返回到第一個界面並顯示

package com.example.myapplication.intentforresult;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

import com.example.myapplication.R;

/**
 * 請求結果
 */
public class RequestActivity extends AppCompatActivity {

    TextView textView;
    Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_request);
        textView = findViewById(R.id.text_view_request);
        button = findViewById(R.id.btn_for_result);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(RequestActivity.this,ResponseActivity.class);
                startActivityForResult(intent,1);
            }
        });
    }

    //獲取請求結果
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        String msg = data.getStringExtra("result");
        if(1 == requestCode){
            if(2 == resultCode){
                textView.setText(msg);
            }
        }
    }
}

<?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:id="@+id/text_view_request"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"/>

    <Button
        android:id="@+id/btn_for_result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:text="請求數據"/>

</LinearLayout>

輸入數據並返回界面

package com.example.myapplication.intentforresult;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.myapplication.R;

/**
 * 返回結果
 */
public class ResponseActivity extends AppCompatActivity {

    EditText editText;
    Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_response);
        editText = findViewById(R.id.edit_text_response);
        button = findViewById(R.id.btn_back);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String msg = editText.getText().toString();
                if (TextUtils.isEmpty(msg)) {
                    Toast.makeText(ResponseActivity.this,"輸入不能爲空",Toast.LENGTH_SHORT).show();
                    return;
                }
                Intent intent = new Intent();
                intent.putExtra("result",msg);
                //設置結果碼和數據
                setResult(2,intent);
                //不要忘了調用finish()方法結束當前Activity
                finish();
            }
        });
    }
}

<?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">

    <EditText
        android:id="@+id/edit_text_response"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="請輸入內容"
        android:textSize="20dp"/>

    <Button
        android:id="@+id/btn_back"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="返回結果"/>

</LinearLayout>

這有倆個例子分別是打電話和照相

打電話是跳轉第三方應用，照相不僅調用第三方應用，還用到了數據回傳

下面是打電話的代碼

package com.example.myapplication.intentwithoperate;

import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import com.example.myapplication.R;

/**
 * 調用第三方程序打電話
 */
public class CallPhoneActivity extends AppCompatActivity {

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

    public void callPhone(View view){
        Intent intent = new Intent();
        Uri uri = Uri.parse("tel:10086");
        intent.setData(uri);
        intent.setAction("android.intent.action.CALL");
        intent.addCategory(Intent.CATEGORY_DEFAULT);
        startActivity(intent);
    }
}

<?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">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="撥打電話"
        android:onClick="callPhone"
        android:textSize="20sp"
        android:layout_marginTop="10dp"/>

</LinearLayout>

下面是拍照，注意在虛擬機上無法拍照，所以看不到效果，我在真機上測試沒有問題的

package com.example.myapplication.intentwithoperate;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.example.myapplication.R;

/**
 * 調用相機拍照並返回結果
 */
public class CameraRequestActivity extends AppCompatActivity {

    Button button;
    ImageView imageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_camera_request);
        button = findViewById(R.id.btn_camera);
        imageView = findViewById(R.id.image_camera);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setAction("android.media.action.IMAGE_CAPTURE");
                intent.addCategory(Intent.CATEGORY_DEFAULT);
                startActivityForResult(intent,1);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        /**
         * Activity.RESULT_OK和Activity.RESULT_CANCELED是安卓系統定義的倆個常量，用於表示相機照相的“√”和“×”
         */
        if(1 == requestCode){
            if(Activity.RESULT_OK == resultCode && data != null){
                //用Bitmap來接收照片
                Bitmap bitmap = data.getParcelableExtra("data");
                imageView.setImageBitmap(bitmap);
            }else if(Activity.RESULT_CANCELED == resultCode){
                Toast.makeText(this,"失敗",Toast.LENGTH_SHORT).show();
            }
        }
    }
}

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

    <Button
        android:id="@+id/btn_camera"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="打開相機"
        android:textSize="20sp"/>
    <ImageView
        android:id="@+id/image_camera"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

-----僅爲自己的學習筆記

Android基礎------Activity基礎

應用內Activity的跳轉方式

跳轉到第三方應用，例如手機的瀏覽器，電話

跳轉後獲取數據返回

這有倆個例子分別是打電話和照相

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