android动态申请权限

申请权限对于安卓开发很重要，从Android6.0开始，Android系统提供动态申请权限的机制, APP在使用危险权限时，需要用户的授权才可进一步操作。所以这一篇文章介绍如何动态申请权限。非常简单。

一、在AndroidManifest.xml配置所需要的权限，代码如下

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

    <!--需要配置的权限-->
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <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=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

二、新建一个项目，在MainActivity.java中加入动态申请权限的代码，代码如下

package com.example.camera;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //去除顶部状态栏
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);
        // Android 6.0相机动态权限检查
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)== PackageManager.PERMISSION_GRANTED){
        }else {
            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
        }
        
    }
}

其中requestPermissions的requestcode为1，作为后面的判断用。

第二种方法，新建一个权限的数组，代码如下：

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";

    private static final String[] permission = new String[] {
            Manifest.permission.CAMERA,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //去除顶部状态栏
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);
        // Android 6.0相机动态权限检查
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)== PackageManager.PERMISSION_GRANTED){
        }else {
            ActivityCompat.requestPermissions(this,permission,1);
        }

    }
}