ADD file via upload

main/java/com/example/musicwork/StartActivity.java

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+package com.example.musicwork;
+
+import androidx.appcompat.app.AppCompatActivity;
+import android.os.Bundle;
+import android.content.Intent;
+import android.os.Handler;
+import android.view.KeyEvent;
+
+public class StartActivity extends AppCompatActivity {
+    private Handler handler = new Handler();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        // 注意：此处将setContentView()方法注释掉
+        // setContentView(R.layout.activity_start);
+        handler.postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                gotoLogin();
+            }
+        }, 1500);
+    }
+
+    /**
+     * 前往注册、登录主页
+     */
+    private void gotoLogin() {
+        Intent intent = new Intent(StartActivity.this, SignIn.class);
+        startActivity(intent);
+        finish();
+        //取消界面跳转时的动画，使启动页的logo图片与注册、登录主页的logo图片完美衔接
+        overridePendingTransition(0, 0);
+    }
+
+    /**
+     * 屏蔽物理返回键
+     */
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        if (keyCode == KeyEvent.KEYCODE_BACK) {
+            return true;
+        }
+        return super.onKeyDown(keyCode, event);
+    }
+
+    @Override
+    protected void onDestroy() {
+        if (handler != null) {
+            //If token is null, all callbacks and messages will be removed.
+            handler.removeCallbacksAndMessages(null);
+        }
+        super.onDestroy();
+    }
+
+
+}