我正在尝试制作一个能够读取用户当前位置的简单Android GPS应用程序。
在执行此操作时，我需要请求权限。我已经按照Google自己的Android页面上的教程进行了操作。
我的应用程序启动正常，它达到我需要开始请求权限的程度，然后它不再起作用。
我在应用程序中放了几个“调试消息”，将文本打印到textViews。 它只在onConnected（）方法中变为“1”。
任何线索我做错了什么？非常感谢提前！
这是我的活动Java代码
public class StartActivity extends AppCompatActivity implements ConnectionCallbacks, OnConnectionFailedListener {
private Location mLastLocation;
private boolean locationPermissionGoodToGo = false;
private final int MY_PERMISSION_ACCESS_FINE_LOCATION = 1;
// Google client to interact with Google API
private GoogleApiClient mGoogleApiClient;
// UI elements
private TextView mLatitudeText,mLongitudeText, mTextTest, mTextPerRes;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create an instance of GoogleAPIClient.
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
mLatitudeText = (TextView) findViewById(R.id.mLatitudeText);
mLongitudeText = (TextView) findViewById(R.id.mLongitudeText);
mTextTest = (TextView) findViewById(R.id.textTest);
mTextPerRes = (TextView) findViewById(R.id.textPerRes);
LocationRequest mLocationRequest = createLocationRequest();
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
.addLocationRequest(mLocationRequest);
PendingResult<LocationSettingsResult> result =
LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, //mGoogleClient
builder.build());
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_start, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
protected void onStart() {
mGoogleApiClient.connect();
super.onStart();
}
protected void onStop() {
mGoogleApiClient.disconnect();
super.onStop();
}
public boolean refreshLocation(){
return false;
}
@Override
public void onConnected(Bundle bundle) {
mTextPerRes.setText("Permission getting ready");//DEBUG!!!
mTextTest.setText("1");//DEBUG!!!
if ( ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ) {
mTextTest.setText("1.5");//DEBUG!!!
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, MY_PERMISSION_ACCESS_FINE_LOCATION);
}
if(locationPermissionGoodToGo == true) {
//TODO: Kommer inte in här. Något fel med permissions! :(
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
mTextTest.setText("2");//DEBUG!!!
if (mLastLocation != null) {
mTextTest.setText("3");//DEBUG!!!
mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));
mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));
}
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
protected LocationRequest createLocationRequest() {
LocationRequest mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(10000);
mLocationRequest.setFastestInterval(5000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
return mLocationRequest;
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
mTextPerRes.setText("Permission wanted");//DEBUG!!!
switch (requestCode) {
case MY_PERMISSION_ACCESS_FINE_LOCATION: {
mTextPerRes.setText("Permission case right");//DEBUG!!!
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
mTextPerRes.setText("Permission granted");//DEBUG!!!
locationPermissionGoodToGo = true;
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
}
这是我的清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="se.adrianhansson.gpsapp"
android:versionCode="1"
android:versionName="1.0">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
<activity
android:name=".StartActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
我编辑的代码仍然无效。相同的结果。
public class StartActivity extends AppCompatActivity implements ConnectionCallbacks, OnConnectionFailedListener {
private Location mLastLocation;
private boolean locationPermissionGoodToGo = false;
private final int MY_PERMISSION_ACCESS_FINE_LOCATION = 1;
// Google client to interact with Google API
private GoogleApiClient mGoogleApiClient;
// UI elements
private TextView mLatitudeText,mLongitudeText, mTextTest, mTextPerRes;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create an instance of GoogleAPIClient.
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
mLatitudeText = (TextView) findViewById(R.id.mLatitudeText);
mLongitudeText = (TextView) findViewById(R.id.mLongitudeText);
mTextTest = (TextView) findViewById(R.id.textTest);
mTextPerRes = (TextView) findViewById(R.id.textPerRes);
LocationRequest mLocationRequest = createLocationRequest();
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
.addLocationRequest(mLocationRequest);
PendingResult<LocationSettingsResult> result =
LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, //mGoogleClient
builder.build());
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_start, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
protected void onStart() {
mGoogleApiClient.connect();
super.onStart();
}
protected void onStop() {
mGoogleApiClient.disconnect();
super.onStop();
}
public boolean refreshLocation(){
return false;
}
@Override
public void onConnected(Bundle bundle) {
mTextPerRes.setText("Permission getting ready");//DEBUG!!!
mTextTest.setText("1");//DEBUG!!!
if ( ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ) {
mTextTest.setText("1.5");//DEBUG!!!
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, MY_PERMISSION_ACCESS_FINE_LOCATION);
}
setCoordinates();
// original location of setCoordinates() code
}
public void setCoordinates(){
if(locationPermissionGoodToGo == true) {
//TODO: Kommer inte in här. Något fel med permissions! :(
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
mTextTest.setText("2");//DEBUG!!!
if (mLastLocation != null) {
mTextTest.setText("3");//DEBUG!!!
mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));
mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));
}
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
protected LocationRequest createLocationRequest() {
LocationRequest mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(10000);
mLocationRequest.setFastestInterval(5000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
return mLocationRequest;
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
mTextPerRes.setText("Permission wanted");//DEBUG!!!
switch (requestCode) {
case MY_PERMISSION_ACCESS_FINE_LOCATION: {
mTextPerRes.setText("Permission case right");//DEBUG!!!
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
mTextPerRes.setText("Permission granted");//DEBUG!!!
locationPermissionGoodToGo = true;
setCoordinates();
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
locationPermissionGoodToGo = false;
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
}
答案 0 :(得分：1)
requestPermissions()是异步的。您在调用它后立即检查locationPermissionGoodToGo，这太早 。
将if(locationPermissionGoodToGo == true)块中的代码移动到单独的方法中。如果checkSelfPermission()表示您拥有该权限，请立即调用该单独方法。否则，请在onRequestPermissionResult()中将其设置为locationPermissionGoodToGo至true。