Android在Main活动之前检查权限

Question

在我的应用程序上，我实现了一个启动活动，检查是否是第一个运行的应用程序，如果是true，则显示一条对话框消息，这是代码：

public void onConnected(Bundle connectionHint) {
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
myLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
}
SharedPreferences getPrefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
boolean isFirstStart = getPrefs.getBoolean("firstStart", true);
if (isFirstStart) {
android.app.AlertDialog alertDialog = new android.app.AlertDialog.Builder(splashscreen.this).create();
alertDialog.setTitle(getResources().getString(R.string.titolo_intro_sms));
alertDialog.setMessage(getResources().getString(R.string.intro_sms));
alertDialog.setButton(android.app.AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent i = new Intent(splashscreen.this, MainActivity.class);
startActivity(i);
}
});
alertDialog.show();
SharedPreferences.Editor e = getPrefs.edit();
e.putBoolean("firstStart", false);
e.apply();
} else {
startApp();
}
}

当对话框显示时，如果单击"确定"，我将打开MainActivity。现在，在"确定"之后，在开始MainActivity之前单击对话框，我想显示一个对话框请求权限。我已经为此创建了一个抽象类，并以这种方式调用：

requestAppPermissions(new String[]{
Manifest.permission.ACCESS_COARSE_LOCATION},
R.string.msg,REQUEST_PERMISSION);

现在我将这行代码设置为OnCreate，权限请求在启动活动之前显示，但如果我设置为"确定"对话框的onClick方法，则不会显示。

在开始"主活动"之前，单击"确定"后，如何显示权限请求？任何帮助都很棒感谢

我已经以这种方式将onRequestPermissionresult集成到抽象类中：

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
int permissionCheck = PackageManager.PERMISSION_GRANTED;
for(int permisson : grantResults) {
permissionCheck = permissionCheck + permisson;
}
if( (grantResults.length > 0) && PackageManager.PERMISSION_GRANTED == permissionCheck) {
onPermissionsGranted(requestCode);
Intent i = new Intent(this, MainActivity.class); //start activity
startActivity(i);
} else {
//Display message when contain some Dangerous permisson not accept
Snackbar.make(findViewById(android.R.id.content), mErrorString.get(requestCode),
Snackbar.LENGTH_INDEFINITE).setAction("ENABLE", new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent();
i.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
i.setData(Uri.parse("package:" + getPackageName()));
i.addCategory(Intent.CATEGORY_DEFAULT);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
i.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
startActivity(i);
}
}).show();
}
}

并且消息权限在ok点击后显示，但在应用程序关闭而未打开MainActivity 后显示

我已经更改了我的splashcrenn，并且我已经将所有关于置换的方法设置到它中，这是代码：

public void onPermissionsGranted(int requestCode) {
}
public void requestAppPermissions(final String[]requestedPermissions, final int stringId, final int requestCode) {
mErrorString.put(requestCode, stringId);
int permissionCheck = PackageManager.PERMISSION_GRANTED;
boolean showRequestPermissions = false;
for(String permission: requestedPermissions) {
permissionCheck = permissionCheck + ContextCompat.checkSelfPermission(this, permission);
showRequestPermissions = showRequestPermissions || ActivityCompat.shouldShowRequestPermissionRationale(this, permission);
}
if (permissionCheck!=PackageManager.PERMISSION_GRANTED) {
if(showRequestPermissions) {
Snackbar.make(findViewById(android.R.id.content), stringId, Snackbar.LENGTH_INDEFINITE).setAction("GRANT", new View.OnClickListener() {
@Override
public void onClick(View v) {
ActivityCompat.requestPermissions(splashscreen.this, requestedPermissions, requestCode);
}
}).show();
} else {
ActivityCompat.requestPermissions(this, requestedPermissions, requestCode);
}
} else {
onPermissionsGranted(requestCode);
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getApplicationContext(), "Permission granted", Toast.LENGTH_SHORT).show();
Intent i = new Intent(splashscreen.this, MainActivity.class); //start activity
splashscreen.this.startActivity(i);
} else {
Toast.makeText(getApplicationContext(), "Permission denied", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}

进入对话框"确定"点击按钮我已经设置了这个：

alertDialog.setButton(android.app.AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(splashscreen.this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
/*Intent i = new Intent(splashscreen.this, MainActivity.class);
startActivity(i);*/
}
});
alertDialog.show();

但当我点击"确定"时，应用程序关闭而不打开MainActivity

Answer 1

试试这个：

单击按钮显示权限对话框：

alertDialog.setButton(android.app.AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1); //show reuest dialog
}
});
alertDialog.show();

现在在onRequestPermissionsResult()中获取结果并启动MainActivity

@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getContext(), "Permission granted", Toast.LENGTH_SHORT).show();
Intent i = new Intent(splashscreen.this, MainActivity.class); //start activity
startActivity(i);
} else {
Toast.makeText(getContext(), "Permission denied", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}

在抽象类中，传递活动上下文并使用它启动MainActivity

传递上下文：

class YourAbstractClass{
// variable to hold context
private Context context;
//save the context recievied via constructor in a local variable
public YourAbstractClass(Context context){  //constructor
this.context=context;
}
}

在你的启动活动中，调用你的抽象类，比如：

YourAbstractClass class = new YourAbstractClass(this); //pass context

现在使用上下文到startActivity

Intent myIntent = new Intent(context, MainActivity.class);
context.startActivity(myIntent);

Answer 2

单击"确定"后请求权限，但不要立即启动活动。等待onRequestPermissionResult中的结果，然后在那里启动MainActivity。

Answer 3

在按钮调用中使用if-else语句。

如果您已经拥有权限，则在中执行MainActivity调用if部分。如果没有，请在If else的else部分请求许可。

现在使用OnRequestPermissionResult方法，当授予或拒绝权限时会调用该方法。如果在此方法中授予了权限，则再次执行MainActivity调用，或者在权限被拒绝时执行您需要执行的操作，例如向他显示您需要权限的原因，然后重试或退出。

希望它能有所帮助。有关android简化版中权限的所有信息，请单击此处(http://www.vogella.com/tutorials/AndroidPermissions/article.html)。