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
在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);
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
在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
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);