安卓 |如何在显示下一个对话之前关闭上一个对话？

Question

我有多个不同条件的对话盒。当我为一种情况显示对话时，然后我尝试为另一种情况显示另一种对话。它与上一个重叠。

具体场景

我有两个对话。一个用于当 wifi 不活动时。另一种是当 wifi 处于活动状态时。假设当我启动一个应用程序时，wifi 没有激活。因此，它显示了一个对话。然后我打开了wifi。它显示了另一个对话。但是，它与前一个重叠。在下面的屏幕截图中，通过查看对话框的阴影可以清楚地看到。左边是打开wifi的时候。然后我关掉了wifi再打开。这种重叠发生了。

ScreenShots

Java 代码

 private BroadcastReceiver wifiStateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int wifiStateExtra = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,
                    WifiManager.WIFI_STATE_UNKNOWN);
            switch (wifiStateExtra) {


                case WifiManager.WIFI_STATE_ENABLED:
                    //WIFI ENABLED

                    {
                    info = wifiManager.getConnectionInfo();
                    if (!info.getSSID().trim().equals(ssid)) {
                        title = "Connect to Devil";
                        msg = "In order to work with system you need to be connected with Devil";

                        builder.setTitle(title);
                        builder.setMessage(msg);
                        builder.setPositiveButton("OK", (dialog, which) -> startActivity(WiFiIntent));
                        builder.setNegativeButton("Close App", ((dialog, which) -> finishAffinity()));
                        alertDialog = builder.create();
                        alertDialog.show();
                        alertDialog.setCancelable(false);

                    }

                    break;
                }


                case WifiManager.WIFI_STATE_DISABLED:
                    //WIFI DISABLED
                {
                    title = "Enable WiFi";
                    msg = "Please enable wifi and connect to Devil";
                    builder.setTitle(title);
                    builder.setMessage(msg);
                    builder.setPositiveButton("OK", (dialog, which) -> startActivity(WiFiIntent));
                    builder.setNegativeButton("Close App", ((dialog, which) -> finishAffinity()));
                    alertDialog = builder.create();
                    alertDialog.show();
                    alertDialog.setCancelable(false);
                    break;
                }
            }
        }
    };

Answer 1

在显示下一个对话框之前，您必须关闭上一个显示的对话框。

请检查此代码，它可以根据您的要求正常工作

public class MainActivity extends AppCompatActivity {

    private MaterialAlertDialogBuilder materialDialog;
    private AlertDialog dialog;
    private String title;
    private String msg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        materialDialog = new MaterialAlertDialogBuilder(this);
    }

    @Override
    protected void onStart() {
        super.onStart();
        IntentFilter intentFilter = new IntentFilter(WifiManager.WIFI_STATE_CHANGED_ACTION);

        registerReceiver(wifiStateReceiver, intentFilter);
    }

    @Override
    protected void onStop() {
        super.onStop();
        unregisterReceiver(wifiStateReceiver);
    }

    private final BroadcastReceiver wifiStateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int wifiStateExtra = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);

            switch (wifiStateExtra) {

                case WifiManager.WIFI_STATE_ENABLED:
                    title = "Connected";
                    msg = "Wifi Enabled.";
                    materialDialog.setPositiveButton("ok", (dialogInterface, i) -> {
                        dialogInterface.dismiss();
                    }).setNegativeButton("close", (dialogInterface, i) -> {                    
                    dialogInterface.dismiss();
                        showToast(msg);
                    });

                    break;
                case WifiManager.WIFI_STATE_DISABLED:
                    title = "disconnected";
                    msg = "Wifi Disabled.";
                    materialDialog.setPositiveButton("ok", (dialogInterface, i) -> {
                        dialogInterface.dismiss();
                    }).setNegativeButton("close", (dialogInterface, i) -> {                       
                      dialogInterface.dismiss();
                        showToast(msg);
                    });
                    break;
            }

            if (dialog != null && dialog.isShowing()) {
                dialog.dismiss();
            }

            dialog = materialDialog.setTitle(title).setMessage(msg).create();
            dialog.show();
        }
    };

    private void showToast(String msg) {
        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
    }
}

Answer 2

在重新分配alertDialog之前，只需致电cancel：

...
alertDialog.cancel(); // add this line
alertDialog = builder.create();
...