IllegalStateException - 调用DialogFragment.show（）方法后，无法在onSaveInstanceState之后执行此操作

Question

我正在开发一个关于如何请求ACCESS_FINE_LOCATION权限的Android 6.0应用示例，就像在下图中一样。

选择DENY选项时，我想向用户显示一个自定义对话框，但它会抛出以下异常：

IllegalStateException - Can not perform this action after onSaveInstanceState

调用方法时抛出的

：

grantPermissionDialog.show(getSupportFragmentManager(),"GrantPermissionDialog");

在onRequestPermissionsResult方法

中

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode == REQUEST_ACCESS_FINE_LOCATION){
        if(grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
            Toast.makeText(this, "Location permission granted", Toast.LENGTH_LONG).show();
        }else{
            grantPermissionDialog.show(getSupportFragmentManager(),"GrantPermissionDialog");
        }
    }
}

我想这是因为调用了getSupportFragmentManager()方法。 这是我的GrantPermissionDialog代码。

public class GrantPermissionDialog extends DialogFragment {

private int statusCode;
private String message="El permiso de ubicación es necesario para que esta aplicación funcione.";
private String positiveButtonText="Salir";
private String negativeButtonText="Solicitar permiso";
public static int EXIT_APPLICATION=0;
public static int REQUEST_PERMISSION=1;

@NonNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setMessage(message);
    builder.setPositiveButton(positiveButtonText, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
                statusCode = EXIT_APPLICATION;
        }
    });
    builder.setNegativeButton(negativeButtonText, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            statusCode = REQUEST_PERMISSION;
        }
    });
    return builder.create();
}


public int getStatusCode() {
    return statusCode;
}

}

有关如何解决此问题的任何想法？

Answer 1

这是一个众所周知的场景，并且得到了很好的解释here。根据那篇文章，它引起了

  

因为您尝试在保存活动状态后提交FragmentTransaction

您应该将show（）对话框代码移动到“onPostResume（）”并使用所述的标记here

private boolean mRequestPermissionsWithResult = false;    

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode == REQUEST_ACCESS_FINE_LOCATION){
        if(grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
            Toast.makeText(this, "Location permission granted", Toast.LENGTH_LONG).show();
        }else{
            mRequestPermissionsWithResult = true;
        }
    }
}

@Override
protected void onPostResume() {
    super.onPostResume();
    if (mRequestPermissionsWithResult) {
        grantPermissionDialog.show(getSupportFragmentManager(),"GrantPermissionDialog");
    }
    mRequestPermissionsWithResult = false;
}