我设计了一个函数，该函数可以从SD获取/设置资源，如果从sd中找不到资源，则从Asset获取资源，如果可能的话将资产写回到SD。
此函数可以通过方法调用来检查SD是否已安装并可以访问...
boolean bSDisAvalaible = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);我设计的功能可以从一个应用程序（项目）用于另一个应用程序（有或没有android.permission.WRITE_EXTERNAL_STORAGE）
然后，我想在不玩SecurityException的情况下检查当前应用程序是否具有此特定权限。
它是否存在“不错”的方式在运行时查询当前定义的权限？
Answers:
您可以Context.checkCallingorSelfPermission()为此使用功能。这是一个例子：
private boolean checkWriteExternalPermission()
{
String permission = android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
int res = getContext().checkCallingOrSelfPermission(permission);
return (res == PackageManager.PERMISSION_GRANTED);
}checkCallingPermission()代替checkCallingOrSelfPermission()方法。
这也是另一种解决方案
PackageManager pm = context.getPackageManager();
int hasPerm = pm.checkPermission(
android.Manifest.permission.WRITE_EXTERNAL_STORAGE,
context.getPackageName());
if (hasPerm != PackageManager.PERMISSION_GRANTED) {
// do stuff
}共享我的方法，以防有人需要它们：
/** Determines if the context calling has the required permission
* @param context - the IPC context
* @param permissions - The permissions to check
* @return true if the IPC has the granted permission
*/
public static boolean hasPermission(Context context, String permission) {
int res = context.checkCallingOrSelfPermission(permission);
Log.v(TAG, "permission: " + permission + " = \t\t" +
(res == PackageManager.PERMISSION_GRANTED ? "GRANTED" : "DENIED"));
return res == PackageManager.PERMISSION_GRANTED;
}
/** Determines if the context calling has the required permissions
* @param context - the IPC context
* @param permissions - The permissions to check
* @return true if the IPC has the granted permission
*/
public static boolean hasPermissions(Context context, String... permissions) {
boolean hasAllPermissions = true;
for(String permission : permissions) {
//you can return false instead of assigning, but by assigning you can log all permission values
if (! hasPermission(context, permission)) {hasAllPermissions = false; }
}
return hasAllPermissions;
}并称之为：
boolean hasAndroidPermissions = SystemUtils.hasPermissions(mContext, new String[] {
android.Manifest.permission.ACCESS_WIFI_STATE,
android.Manifest.permission.READ_PHONE_STATE,
android.Manifest.permission.ACCESS_NETWORK_STATE,
android.Manifest.permission.INTERNET,
});您应该按照以下方式检查权限（如此处Android权限所述）：
int result = ContextCompat.checkSelfPermission(getContext(), Manifest.permission.READ_PHONE_STATE);然后，将您的结果与以下任意一项进行比较：
result == PackageManager.PERMISSION_DENIED要么：
result == PackageManager.PERMISSION_GRANTED第1步 -添加权限请求
String[] permissionArrays = new String[]{Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE};
int REQUEST_CODE = 101;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(permissionArrays, REQUEST_CODE );
} else {
// if already permition granted
// PUT YOUR ACTION (Like Open cemara etc..)
}
}第2步 -处理权限结果
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
boolean openActivityOnce = true;
boolean openDialogOnce = true;
if (requestCode == REQUEST_CODE ) {
for (int i = 0; i < grantResults.length; i++) {
String permission = permissions[i];
isPermitted = grantResults[i] == PackageManager.PERMISSION_GRANTED;
if (grantResults[i] == PackageManager.PERMISSION_DENIED) {
// user rejected the permission
}else {
// user grant the permission
// you can perfome your action
}
}
}
}对我来说很好的代码是：
final int MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE = 102;
if ((ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
} else {
// user already provided permission
// perform function for what you want to achieve
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
boolean canUseExternalStorage = false;
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE: {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
canUseExternalStorage = true;
}
if (!canUseExternalStorage) {
Toast.makeText(getActivity(), "Cannot use this feature without requested permission", Toast.LENGTH_SHORT).show();
} else {
// user now provided permission
// perform function for what you want to achieve
}
}
}
}启用GPS位置Android Studio
MapsActivity.java
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private Context context;
private static final int PERMISSION_REQUEST_CODE = 1;
Activity activity;
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
@Override
protected void onCreate(Bundle savedInstanceState) {
context = getApplicationContext();
activity = this;
super.onCreate(savedInstanceState);
requestPermission();
checkPermission();
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
LatLng location = new LatLng(0, 0);
mMap.addMarker(new MarkerOptions().position(location).title("Marker in Bangalore"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(location));
mMap.setMyLocationEnabled(true);
}
private void requestPermission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.ACCESS_FINE_LOCATION)) {
Toast.makeText(context, "GPS permission allows us to access location data. Please allow in App Settings for additional functionality.", Toast.LENGTH_LONG).show();
} else {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSION_REQUEST_CODE);
}
}
private boolean checkPermission() {
int result = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION);
if (result == PackageManager.PERMISSION_GRANTED) {
return true;
} else {
return false;
}
}if ((ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) && (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) && (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA},
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
}
} 在KOTLIN中检查权限（运行时）
在清单中：（android.permission.WRITE_EXTERNAL_STORAGE）
fun checkPermissions(){
var permission_array=arrayOf(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
if((ContextCompat.checkSelfPermission(this,permission_array[0]))==PackageManager.PERMI SSION_DENIED){
requestPermissions(permission_array,0)
}
}
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if(requestCode==0 && grantResults[0]==PackageManager.PERMISSION_GRANTED){
//Do Your Operations Here
---------->
//
}
}