文章目录
MyTool 工具界面：
♦ 回顾
通过上一节的学习，我们实现了工具界面百度、拨号功能的实现，如下图所示。今天，要在这个界面中实现一个新的功能手电筒。
♦ 设置 activity_my_tool.xml 界面
- 添加一个新的
按钮组件：手电筒
<Button
android:id="@+id/flashlight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginStart="39dp"
android:layout_marginLeft="39dp"
android:layout_marginTop="250dp"
android:text="手电筒"
android:textSize="16dp"/>
♦ 编写 MyToolActivity 实现功能界面跳转
public class MyToolActivity extends AppCompatActivity {
TextView welcome;
Button net, call, quick_call,flashlight;
//权限请求：载入界面、特定情况触发
//定义权限 --- 动态权限，申请哪一个就启动哪一个，通常为常量
private static String[] PERMISSIONS_STORAGE = {
Manifest.permission.CALL_PHONE
};
//请求状态码
private static int REQUEST_PERMISSION_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_tool);
.........................
// 获取工具组件
net = findViewById(R.id.net);
call = findViewById(R.id.call);
quick_call = findViewById(R.id.quick_call);
flashlight = findViewById(R.id.flashlight);
.........................
// 手电筒界面跳转
flashlight.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 创建页面跳转
Intent intent = new Intent();
intent.setClass(MyToolActivity.this,FlashLightActivity.class);
startActivity(intent);
}
});
}
}
♦ 创建 activity_flash_light.xml 手电筒界面
-
基本布局、背景
-
添加 ImageButton 组件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.myapplication.FlashLightActivity"
android:background="@drawable/main_page">
<TextView
android:id="@+id/textView9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="76dp"
android:text="欢迎使用手电筒！"
android:textStyle="bold"
android:textColor="@android:color/white"
android:textSize="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.511"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageButton
android:id="@+id/imageButton"
android:layout_width="255dp"
android:layout_height="247dp"
android:layout_alignParentTop="true"
android:layout_centerInParent="true"
android:layout_marginTop="218dp"
android:scaleType="centerInside"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.644"
app:srcCompat="@drawable/off" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="195dp"
android:text="已关闭!"
android:textSize="20dp"
android:textStyle="bold"
android:textColor="@android:color/white"
/>
<SurfaceView
android:id="@+id/surfaceView"
android:layout_width="149dp"
android:layout_height="109dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="124dp"
android:layout_marginBottom="7dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</RelativeLayout>
由于手电筒（闪光灯）常与照相机放在一起使用，不妨这里我们添加一个SurfaceView用于模拟照相功能。
♦ 编写 FlashLightActivity 实现功能
package com.example.myapplication;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import android.Manifest;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Build;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;
import java.io.IOException;
public class FlashLightActivity extends AppCompatActivity {
// 定义对象
ImageButton flashlight;
TextView showNow;
boolean isFlag = false;
// 创建相机对象
Camera cc;
Camera.Parameters pp;
SurfaceView sv;
SurfaceHolder sh;
//权限请求：载入界面、特定情况触发
//定义权限 --- 动态权限，申请哪一个就启动哪一个，通常为常量
private static String[] PERMISSIONS_STORAGE = {
Manifest.permission.CAMERA
};
//请求状态码
private static int REQUEST_PERMISSION_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_flash_light);
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
// 检查当前的权限
if (ActivityCompat.checkSelfPermission(FlashLightActivity.this, Manifest.permission.CAMERA) !=
PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(FlashLightActivity.this,PERMISSIONS_STORAGE,REQUEST_PERMISSION_CODE);
}
}
flashlight = findViewById(R.id.imageButton);
showNow = findViewById(R.id.textView8);
sv = findViewById(R.id.surfaceView);
cc = Camera.open();
pp = cc.getParameters();
sh = sv.getHolder();
sh.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(@NonNull SurfaceHolder holder) {
try {
cc.setPreviewDisplay(sh);
cc.startPreview();
} catch (IOException e) {
e.printStackTrace();
cc.release();
}
}
@Override
public void surfaceChanged(@NonNull SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(@NonNull SurfaceHolder holder) {
}
});
flashlight.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(isFlag==false){
flashlight.setImageDrawable(getResources().getDrawable(R.drawable.on));
showNow.setText("已开启!");
pp.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
cc.setParameters(pp);
isFlag = true;
} else {
flashlight.setImageDrawable(getResources().getDrawable(R.drawable.off));
showNow.setText("已关闭!");
pp.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
cc.setParameters(pp);
isFlag = false;
}
}
});
}
}
♦ 修改AndroidManifest.xml文件授权
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapplication_test">
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.CAMERA" /> 添加摄像权限
<uses-permission android:name="android.permission.FLASHLIGHT" /> 添加电筒权限
<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/AppTheme">
<activity android:name="com.example.myapplication.MyToolActivity"></activity>
<activity android:name="com.example.myapplication.MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
♦ 测试
