未找到 Activity 来处理 Intent { }

No Activity found to handle Intent { }

在我的 天气应用程序 上,启动画面运行良好,但是当它进入 HomeActivity 时,它显示 app has stopped 我在我的设备上测试了它

logcat上显示:

No Activity found to handle Intent {  }

与此同时,我在启动画面中传递了意图:

        int SPLASH_SCREEN = 5000;
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent = new Intent(MainActivity.this, HomeActivity.class);
                startActivity(intent);
                finish();
            }
        }, SPLASH_SCREEN);
    }
}

我的家庭活动代码:

public class HomeActivity extends AppCompatActivity {
    ConstraintLayout constraintLayout;
    public static int count=0;
    int[] drawable =new int[]{R.drawable.burj_khalifa,R.drawable.central_bank_of_nigeria,R.drawable.eiffel_tower,R.drawable.hong_kong,R.drawable.statue_of_liberty};
    Timer _t;

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

        constraintLayout = (ConstraintLayout) findViewById(R.id.layout);
        constraintLayout.setBackgroundResource(R.drawable.burj_khalifa);
            _t = new Timer();
            _t.scheduleAtFixedRate(new TimerTask() {
                @Override
                        public void run() {
                    runOnUiThread(new Runnable() { // run on ui thread
                        @Override
                        public void run() {
                            if (count < drawable.length) {

                                constraintLayout.setBackgroundResource(drawable[count]);
                                count = (count + 1) % drawable.length;
                            }
                        }
                    });
            }
        }, 5000, 5000);
    }
}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.tex.lightweatherforecast">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".Activity.HomeActivity"
            android:label="@string/title_activity_home" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="preloaded_fonts"
            android:resource="@array/preloaded_fonts" />
    </application>

</manifest> 

activity_home.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/burj_khalifa"
    tools:context=".Activity.HomeActivity">


</androidx.constraintlayout.widget.ConstraintLayout>

有什么可以纠正的吗?

在您的清单中尝试只写 .HomeActivity 而不是 .Activity.HomeActivity 此外,如果它仍然显示错误,我认为你不能写 'R.id.layout' 只是因为 'layout' 是一个关键字所以尝试为你的约束布局定义任何其他 id。

因此,从您的处理程序中删除 finish(); 将解决此问题

       new Handler().postDelayed(new Runnable() {
           @Override
           public void run() {
               Intent intent = new Intent(MainActivity.this, HomeActivity.class);
               startActivity(intent);
               finish();
           }
       }, SPLASH_SCREEN);

如果你想从堆栈中删除启动画面,那么你可以这样做

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

Attempt to invoke virtual method 'void androidx.constraintlayout.widget.ConstraintLayout.setBackgroundResource(int)' on a null object reference

现在您进入了 HomeActivity onCreate,这与 No Activity found to handle Intent { } 错误不同。

这表明您在以下语句中的 constraintLayout 为空,您不能调用 setBackgroundResource 除非您使用非空值

对其进行初始化
 constraintLayout.setBackgroundResource(R.drawable.burj_khalifa);

您是从 activity 布局中获取的,您需要检查此 ID R.id.layout 是否确实存在于 activity_home.xml 布局中作为第一个故障排除步骤

 constraintLayout = (ConstraintLayout) findViewById(R.id.layout);