Activity改为AppCompatActivity

app/src/main/java/com/lyq/autocall/MainActivity.java

@@ -19,7 +19,9 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
-public class MainActivity extends Activity {
+import androidx.appcompat.app.AppCompatActivity;
+
+public class MainActivity extends AppCompatActivity {
     SharedPreferences sharedPreferences;//保存输入过的号码
     EditText edt1, edt2;
     TextView tv1, tv2;
@@ -132,7 +134,7 @@ public class MainActivity extends Activity {
 
     }
 
-    Handler handler = new Handler() {
+    final Handler handler = new Handler() {
 
         @SuppressLint("HandlerLeak")
         @Override