How to set AlterDialog globally in android studio

问题

Using this solution, I am trying to display a loading box using 'AlterDialog'.

public void setProgressDialogRelayResponse() {

    int llPadding = 30;
    LinearLayout ll = new LinearLayout(mContext);
    ll.setOrientation(LinearLayout.HORIZONTAL);
    ll.setPadding(llPadding, llPadding, llPadding, llPadding);
    ll.setGravity(Gravity.CENTER);
    LinearLayout.LayoutParams llParam = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.WRAP_CONTENT,
            LinearLayout.LayoutParams.WRAP_CONTENT);
    llParam.gravity = Gravity.CENTER;
    ll.setLayoutParams(llParam);

    ProgressBar progressBar = new ProgressBar(mContext);
    progressBar.setIndeterminate(true);
    progressBar.setPadding(0, 0, llPadding, 0);
    progressBar.setLayoutParams(llParam);

    llParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
            ViewGroup.LayoutParams.WRAP_CONTENT);
    llParam.gravity = Gravity.CENTER;
    TextView tvText = new TextView(mContext);
    tvText.setText("Status Verification.....");
    tvText.setTextColor(Color.RED);
    tvText.setTextSize(20);
    tvText.setLayoutParams(llParam);

    ll.addView(progressBar);
    ll.addView(tvText);

    AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
    builder.setCancelable(true);
    builder.setView(ll);

     AlertDialog dialog = builder.create();
    dialog.show();
     dialog.setCancelable(false);
    Window window = dialog.getWindow();
    if (window != null) {
        WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
        layoutParams.copyFrom(dialog.getWindow().getAttributes());
        layoutParams.width = LinearLayout.LayoutParams.WRAP_CONTENT;
        layoutParams.height = LinearLayout.LayoutParams.WRAP_CONTENT;
        dialog.getWindow().setAttributes(layoutParams);
    }
}

It's displaying but it keeps on showing. I want to dismiss it when a certain method is performed. For this I want to set the AlteDialog globally. I have tried the following

public class NewFormFragment extends Fragment {
public AlertDialog dialog = new AlertDialog(); }

it gives me error: no suitable constructor found for AlertDialog(no arguments)

Then I tried the following

 public AlertDialog dialog = new AlertDialog(getActivity());

Which gives me bellow error

error: no suitable constructor found for AlertDialog(Activity)

Then I do the following

error: no suitable constructor found for AlertDialog(Context) 

Provided: Context mContext;

It also gives me the same error

error: no suitable constructor found for AlertDialog(Context)

Finally I tried the following

AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
public AlertDialog dialog = builder.create();

But at this time my app crashes after login screen with the following error.

  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.thumbsol.accuratemobileassetsmanagament/com.thumbsol.accuratemobileassetsmanagament.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources$Theme android.content.Context.getTheme()' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2946)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3081)
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1831)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:201)
    at android.app.ActivityThread.main(ActivityThread.java:6810)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources$Theme android.content.Context.getTheme()' on a null object reference
    at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:224)
    at android.app.AlertDialog$Builder.<init>(AlertDialog.java:465)
    at com.thumbsol.accuratemobileassetsmanagament.fragment.NewFormFragment.<init>(NewFormFragment.java:339)
    at com.thumbsol.accuratemobileassetsmanagament.MainActivity.onCreate(MainActivity.java:76)
    at android.app.Activity.performCreate(Activity.java:7224)
    at android.app.Activity.performCreate(Activity.java:7213)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1272)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2926)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3081) 
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) 
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1831) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:201) 
    at android.app.ActivityThread.main(ActivityThread.java:6810) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

(NewFormFragment.java:339) is hitting at `AlertDialog.Builder builder = new AlertDialog.Builder(mContext);`

Any help would be highly appreciated

来源：https://stackoverflow.com/questions/63393532/how-to-set-alterdialog-globally-in-android-studio