Android学习--运行时权限

运行时权限

       Android6.0以后Google不再允许开发者直接或许应用的权限，需要在用户知情的情况下授予权限，即需要用到权限的时候弹出一个权限提示框。

以例子说明

主MainActivity中添加打电话功能

package com.example.runtimepermissiontest;

import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = (Button) findViewById(R.id.make_call);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    Intent intent = new Intent(Intent.ACTION_CALL);
                    intent.setData(Uri.parse("tel:10086"));
                    startActivity(intent);
                }catch (Exception e){
                   e.printStackTrace();
                }
            }
        });
    }
}

布局文件activity_main

<?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"
    tools:context=".MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/make_call"
        android:text="make call"/>

</LinearLayout>

AndroidManifest.xml添加权限

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.runtimepermissiontest">

    <uses-permission android:name="android.permission.CALL_PHONE"/>

在Android 7.0模拟器运行报错

missiontest W/System.err: java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:xxxxx cmp=com.android.server.telecom/.components.UserCallActivity } from ProcessRecord{af9004b 16293:com.example.runtimepermissiontest/u0a86} (pid=16293, uid=10086) with revoked permission android.permission.CALL_PHONE
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.os.Parcel.readException(Parcel.java:1683)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.os.Parcel.readException(Parcel.java:1636)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:3071)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1518)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.Activity.startActivityForResult(Activity.java:4224)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.Activity.startActivityForResult(Activity.java:4183)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.Activity.startActivity(Activity.java:4507)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at android.app.Activity.startActivity(Activity.java:4475)
2019-06-01 10:43:35.205 16293-16293/com.example.runtimepermissiontest W/System.err:     at com.example.runtimepermissiontest.MainActivity$1.onClick(MainActivity.java:24)

修改代码

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ......
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.
                        CALL_PHONE) != PackageManager.PERMISSION_GRANTED){
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{
                            Manifest.permission.CALL_PHONE}, 1);
                }else{
                    call();
                }
            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    call();
                }else {
                    Toast.makeText(MainActivity.this,"Permission Denied", Toast.LENGTH_SHORT).show();
                }
            default:
        }
    }

    private void call(){
        try {
            Intent intent = new Intent(Intent.ACTION_CALL);
            intent.setData(Uri.parse("tel:10086"));
            startActivity(intent);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}