• 安卓第一个小项目


    此博客链接:https://www.cnblogs.com/ping2yingshi/p/13112191.html

    学习链接:https://blog.csdn.net/ficey/article/details/80281981

    1新建一个工程,打开activity.main.xml,选择红框部分,删除hello。

     2.新建两个按钮,直接拖拽就可以。

     3.在AndroidManifest.xml中添加源码,注意只是添加代码。原有的东西不要动。

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.wd.flashlight">
        <uses-permission android:name="android.permission.CAMERA" />
        <uses-permission android:name="android.permission.FLASHLIGHT" />
        <uses-feature android:name="android.hardware.Camera" />
        <uses-feature android:name="android.hardware.camera2" />
        <uses-feature android:name="android.hardware.camera2.CameraManager" />

     4.在activity_main.xml中复制如下代码。对,全删了,把你的代码全删了在复制。

    <?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:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    
        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="128dp"
            android:layout_marginLeft="128dp"
            android:layout_marginTop="148dp"
            android:text=""
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <ToggleButton
            android:id="@+id/toggleButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="56dp"
            android:text="ToggleButton"
            app:layout_constraintStart_toStartOf="@+id/button"
            app:layout_constraintTop_toBottomOf="@+id/button" />
    </LinearLayout>

     如何打开activity_main.xml如下图。

     报错如下的错误,这里是因为你没有选择真机运行或者模拟机运行程序。

     在下面的MainActivity.java中复制替换代码

     

     代码:

    package com.example.flashlight;
    
    import android.app.Activity;
    import android.content.Context;
    import android.hardware.Camera;
    import android.hardware.camera2.CameraAccessException;
    import android.hardware.camera2.CameraManager;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.CompoundButton;
    import android.widget.ToggleButton;
    
    //public class MainActivity extends AppCompatActivity {
    public class MainActivity extends Activity {
    
        private CameraManager manager;
        private Camera camera = null;
        private static boolean kaiguan = true;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            //super.onCreate(savedInstanceState);
    
            manager = (CameraManager)getSystemService(Context.CAMERA_SERVICE);
    
            try{
                String [] cameraList = manager.getCameraIdList();
                for (String str:cameraList
                ) {
                    Log.d("List", str);
                }
            }catch (CameraAccessException e){
                Log.e("error",e.getMessage());
            }
            Button open_btn = (Button)findViewById(R.id.button);
    
            open_btn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    try{
                        manager.setTorchMode("0",true);
                    }catch(CameraAccessException e){
                        e.printStackTrace();
                    }
                }
            });
    
            Button close_btn = (Button) findViewById(R.id.button);
            close_btn.setOnClickListener(closeOnClickListener);
    
            ToggleButton toggle_btn = (ToggleButton)findViewById(R.id.toggleButton);
            toggle_btn.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){
                //@Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked){
                    try{
                        manager.setTorchMode("0",isChecked);
                    }catch (CameraAccessException e){
                        e.printStackTrace();
                    }
                }
            });
        }
    
        private View.OnClickListener closeOnClickListener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try{
                    manager.setTorchMode("0",false);
                }catch (CameraAccessException e){
                    e.printStackTrace();
                }
            }
        };
    }

     下面问题可以参考此博客:https://blog.csdn.net/ShiXinXin_Harbour/article/details/103923893 

     最后可能没有成功,那你看看你小象中的参数对吗、调不好就复制下面代码替换你的

     

    apply plugin: 'com.android.application'
    
    android {
        compileSdkVersion 28
        defaultConfig {
            applicationId "com.example.flashlight"
            minSdkVersion 23
            targetSdkVersion 28
            versionCode 1
            versionName "1.0"
            testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        }
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            }
        }
    }
    
    dependencies {
        implementation fileTree(dir: 'libs', include: ['*.jar'])
    
        implementation 'androidx.appcompat:appcompat:1.0.2'
        implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
        testImplementation 'junit:junit:4.12'
        androidTestImplementation 'androidx.test.ext:junit:1.1.0'
        androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
    }

    到此应该就差不多了。

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  • 原文地址:https://www.cnblogs.com/ping2yingshi/p/13112191.html
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