Android搞定权限申请
0x00 前言
使用EasyPermissions库进行申请权限
打开App时就申请权限，如果用户拒绝权限后，会循环申请
如果永久拒绝后，会跳转到设置里继续申请
效果图：
注：不讲原理，先教你怎么实现
0x01 引入依赖
在app的build.gradle里面，添加EasyPermissions的依赖
implementation 'pub.devrel:easypermissions:2.0.0'
添加后点击 File -> Sync Project with Gradle Files 重新构建一些项目
0x02 创建PermissionActivity
创建一个PermissionActivity用于获取权限，布局随意
可以把它设为启动Activity，也可以由SplashActivity转至PermissionActivity
创建完成后，让PermissionActivity实现EasyPermissions.PermissionCallbacks，并重新下面三个方法
PermissionActivity复制下面的内容即可
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import java.util.List;
import pub.devrel.easypermissions.EasyPermissions;
public class PermissionActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_permission);
}
// 重新下面三个方法
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
}
@Override
public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) {
}
@Override
public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) {
}
}
0x03 三个方法
其中onRequestPermissionsResult是权限申请后执行的方法，默认就写成上面那样就行
onPermissionsGranted是权限授权时的回调
onPermissionsDenied是权限被拒绝时的回调
0x04 申请权限
假如要申请存储权限
首先在AndroidManifest.xml里面加上这两行
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
然后，在PermissionActivity里定义两个常量
// 指定申请存储权限时，一个标识符，用于在成功或失败回调中判断申请成功的或失败的是哪几个权限
static final int STORAGE_CALL_BACK_CODE = 0;
// 存储权限
static final String[] perms_storage = new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};
在onCreate里面加上申请权限的代码
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_permission);
if (EasyPermissions.hasPermissions(this, perms_storage)) {
Toast.makeText(this, "已经有存储权限", Toast.LENGTH_SHORT).show();
} else {
EasyPermissions.requestPermissions(this, "请给我权限", STORAGE_CALL_BACK_CODE, perms_storage);
}
}
0x05 处理授权成功
onPermissionsGranted方法
@Override
public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) {
//noinspection SwitchStatementWithTooFewBranches
switch (requestCode) {
// 如果存储权限申请通过
case STORAGE_CALL_BACK_CODE:
Toast.makeText(this, "已同意存储权限", Toast.LENGTH_SHORT).show();
// pass为通过后执行的方法，注意下面有个finish()，pass()中就不要再加finish()了
pass();
finish();
break;
}
}
0x06 处理授权失败
onPermissionsDenied方法
@Override
public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) {
//noinspection SwitchStatementWithTooFewBranches
switch (requestCode) {
case STORAGE_CALL_BACK_CODE:
Toast.makeText(this, "已拒绝存储权限", Toast.LENGTH_SHORT).show();
ActivityCompat.requestPermissions(this, perms_storage, STORAGE_CALL_BACK_CODE);
break;
}
// 如果权限被永久拒绝，就提示到设置页面中开启
if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {
Toast.makeText(this, "权限已被永久拒绝", Toast.LENGTH_SHORT).show();
new AppSettingsDialog
.Builder(this)
.setTitle("权限已被永久拒绝")
.setRationale("该应用需要此权限，否则无法正常使用，是否打开设置")
.setPositiveButton("确定")
.setNegativeButton("取消")
.build()
.show();
}
}
0x07 完整代码
PermissionActivity
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import android.Manifest;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Toast;
import java.util.List;
import pub.devrel.easypermissions.AppSettingsDialog;
import pub.devrel.easypermissions.EasyPermissions;
public class PermissionActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks {
static final int STORAGE_CALL_BACK_CODE = 0;
static final String[] perms_storage = new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_permission);
if (EasyPermissions.hasPermissions(this, perms_storage)) {
Toast.makeText(this, "已经有存储权限", Toast.LENGTH_SHORT).show();
} else {
EasyPermissions.requestPermissions(this, "请给我权限", STORAGE_CALL_BACK_CODE, perms_storage);
}
}
void pass() {
startActivity(new Intent(this, MainActivity.class));
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
}
@Override
public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) {
//noinspection SwitchStatementWithTooFewBranches
switch (requestCode) {
// 如果存储权限申请通过
case STORAGE_CALL_BACK_CODE:
Toast.makeText(this, "已同意存储权限", Toast.LENGTH_SHORT).show();
// pass为通过后执行的方法，注意下面有个finish()，pass()中就不要再加finish()了
pass();
finish();
break;
}
}
@Override
public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) {
//noinspection SwitchStatementWithTooFewBranches
switch (requestCode) {
case STORAGE_CALL_BACK_CODE:
Toast.makeText(this, "已拒绝存储权限", Toast.LENGTH_SHORT).show();
ActivityCompat.requestPermissions(this, perms_storage, STORAGE_CALL_BACK_CODE);
break;
}
// 如果权限被永久拒绝，就提示到设置页面中开启
if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {
Toast.makeText(this, "权限已被永久拒绝", Toast.LENGTH_SHORT).show();
new AppSettingsDialog
.Builder(this)
.setTitle("权限已被永久拒绝")
.setRationale("该应用需要此权限，否则无法正常使用，是否打开设置")
.setPositiveButton("确定")
.setNegativeButton("取消")
.build()
.show();
}
}
}
0x08 项目代码
项目在github上面，有用的话，可以给一个star
