代码之家  ›  专栏  ›  技术社区  ›  Black

应用程序显示半秒钟的黑屏,没有错误地崩溃。

  •  -2
  • Black  · 技术社区  · 5 年前

    我刚刚开始学习Android应用程序开发。我尝试创建一个非常简单的应用程序,它只是在全屏模式下将用户重定向到我们的主页。

    但是如果我启动应用程序,一个黑色窗口会显示不到半秒钟,应用程序就会关闭。

    我不知道如何调试/修复这个问题,我希望有人能帮助初学者!谢谢!

    app\src\main\res\layout\activity\u fullscreen.xml

    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#0099cc"
        tools:context=".FullscreenActivity">
    
        <!-- The primary full-screen view. This can be replaced with whatever view
             is needed to present your content, e.g. VideoView, SurfaceView,
             TextureView, etc. -->
        <WebView android:id="@+id/botecView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:keepScreenOn="true"
            android:textColor="#33b5e5"
            android:textStyle="bold"
            android:textSize="50sp"
            android:gravity="center"
            android:text="@string/dummy_content" />
    
        <!-- This FrameLayout insets its children based on system windows using
             android:fitsSystemWindows. -->
        <FrameLayout android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true">
    
            <LinearLayout android:id="@+id/fullscreen_content_controls"
                style="?metaButtonBarStyle"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom|center_horizontal"
                android:background="@color/black_overlay"
                android:orientation="horizontal"
                tools:ignore="UselessParent">
    
            </LinearLayout>
        </FrameLayout>
    </FrameLayout>
    

    App\Src\Madia\java\COM\Base\FulcStudio Actuviv.java的例子

    package com.example.botec;
    
    import android.annotation.SuppressLint;
    import android.support.v7.app.ActionBar;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.os.Handler;
    import android.view.MotionEvent;
    import android.view.View;
    import android.webkit.WebView;
    import android.util.Log;
    
    /**
     * An example full-screen activity that shows and hides the system UI (i.e.
     * status bar and navigation/system bar) with user interaction.
     */
    public class FullscreenActivity extends AppCompatActivity {
        /**
         * Whether or not the system UI should be auto-hidden after
         * {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
         */
        private static final boolean AUTO_HIDE = true;
    
        /**
         * If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
         * user interaction before hiding the system UI.
         */
        private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
    
        /**
         * Some older devices needs a small delay between UI widget updates
         * and a change of the status and navigation bar.
         */
        private static final int UI_ANIMATION_DELAY = 300;
    
        private View mContentView;
        private View mControlsView;
        private boolean mVisible;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            setContentView(R.layout.activity_fullscreen);
    
            mVisible = true;
    
            // Set up the user interaction to manually show or hide the system UI.
    
            // Upon interacting with UI controls, delay any scheduled hide()
            // operations to prevent the jarring behavior of controls going away
            // while interacting with the UI.
            //findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
    
            WebView botecView = findViewById(R.id.botecView);
            botecView.getSettings().setJavaScriptEnabled(true);
            botecView.loadUrl("https://www.botec.de");
        }
    
        @Override
        protected void onPostCreate(Bundle savedInstanceState) {
            super.onPostCreate(savedInstanceState);
    
            // Trigger the initial hide() shortly after the activity has been
            // created, to briefly hint to the user that UI controls
            // are available.
            delayedHide(100);
        }
    
        /**
         * Touch listener to use for in-layout UI controls to delay hiding the
         * system UI. This is to prevent the jarring behavior of controls going away
         * while interacting with activity UI.
         */
        private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                if (AUTO_HIDE) {
                    delayedHide(AUTO_HIDE_DELAY_MILLIS);
                }
                return false;
            }
        };
    
        private void toggle() {
            if (mVisible) {
                hide();
            } else {
                show();
            }
        }
    
        private void hide() {
            // Hide UI first
            ActionBar actionBar = getSupportActionBar();
            if (actionBar != null) {
                actionBar.hide();
            }
            mControlsView.setVisibility(View.GONE);
            mVisible = false;
    
            // Schedule a runnable to remove the status and navigation bar after a delay
            mHideHandler.removeCallbacks(mShowPart2Runnable);
            mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
        }
    
        private final Runnable mHidePart2Runnable = new Runnable() {
            @SuppressLint("InlinedApi")
            @Override
            public void run() {
                // Delayed removal of status and navigation bar
    
                // Note that some of these constants are new as of API 16 (Jelly Bean)
                // and API 19 (KitKat). It is safe to use them, as they are inlined
                // at compile-time and do nothing on earlier devices.
                mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
            }
        };
    
        @SuppressLint("InlinedApi")
        private void show() {
            // Show the system bar
            mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
            mVisible = true;
    
            // Schedule a runnable to display UI elements after a delay
            mHideHandler.removeCallbacks(mHidePart2Runnable);
            mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
        }
    
        private final Runnable mShowPart2Runnable = new Runnable() {
            @Override
            public void run() {
                // Delayed display of UI elements
                ActionBar actionBar = getSupportActionBar();
                if (actionBar != null) {
                    actionBar.show();
                }
                mControlsView.setVisibility(View.VISIBLE);
            }
        };
    
        private final Handler mHideHandler = new Handler();
        private final Runnable mHideRunnable = new Runnable() {
            @Override
            public void run() {
                hide();
            }
        };
    
        /**
         * Schedules a call to hide() in delay milliseconds, canceling any
         * previously scheduled calls.
         */
        private void delayedHide(int delayMillis) {
            mHideHandler.removeCallbacks(mHideRunnable);
            mHideHandler.postDelayed(mHideRunnable, delayMillis);
        }
    }
    

    LogCAT(空):

    enter image description here

    2 回复  |  直到 5 年前
        1
  •  0
  •   clauub    5 年前

    对于您在注释中显示的错误,我有两个选项: 7847-7847/com.huawei.hwdetectrepair E/SmartNotifyService: intent null in onStartCommand

    第一个:

    您应将支票延期至:

    if(intent != null && intent.getAction() != null) {
    

    如果要将操作添加到您的意图中,您需要调用[setAction()][1]:

    Intent i = new Intent(this, MainService.class);
    i.setAction("foo");
    startService(i);
    

    第二种:

    只需尝试添加此简单检查:

    intent.getAction() != null
    

    希望有帮助。让我知道:

        2
  •  0
  •   Black    5 年前

    好的,似乎有不需要的代码。我把它改成了:

    app\src\main\res\layout\activity\u fullscreen.xml

    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#0099cc"
        tools:context=".FullscreenActivity">
    
        <!-- The primary full-screen view. This can be replaced with whatever view
             is needed to present your content, e.g. VideoView, SurfaceView,
             TextureView, etc. -->
        <WebView android:id="@+id/botecView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:keepScreenOn="true"
            android:gravity="center" />
    </FrameLayout>
    

    App\Src\Madia\java\COM\Base\FulcStudio Actuviv.java的例子

    package com.example.botec;
    
    import android.annotation.SuppressLint;
    import android.support.v7.app.ActionBar;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.os.Handler;
    import android.view.MotionEvent;
    import android.view.View;
    import android.webkit.WebView;
    import android.util.Log;
    
    /**
     * An example full-screen activity that shows and hides the system UI (i.e.
     * status bar and navigation/system bar) with user interaction.
     */
    public class FullscreenActivity extends AppCompatActivity {
        /**
         * Whether or not the system UI should be auto-hidden after
         * {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
         */
        private static final boolean AUTO_HIDE = true;
    
        /**
         * If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
         * user interaction before hiding the system UI.
         */
        private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
    
        /**
         * Some older devices needs a small delay between UI widget updates
         * and a change of the status and navigation bar.
         */
        private static final int UI_ANIMATION_DELAY = 300;
        private boolean mVisible;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            setContentView(R.layout.activity_fullscreen);
    
            mVisible = true;
    
            WebView botecView = findViewById(R.id.botecView);
            botecView.getSettings().setJavaScriptEnabled(true);
            botecView.loadUrl("https://www.botec.de");
        }
    
        @Override
        protected void onPostCreate(Bundle savedInstanceState) {
            super.onPostCreate(savedInstanceState);
    
            // Trigger the initial hide() shortly after the activity has been
            // created, to briefly hint to the user that UI controls
            // are available.
            delayedHide(100);
        }
    
        /**
         * Touch listener to use for in-layout UI controls to delay hiding the
         * system UI. This is to prevent the jarring behavior of controls going away
         * while interacting with activity UI.
         */
        private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                if (AUTO_HIDE) {
                    delayedHide(AUTO_HIDE_DELAY_MILLIS);
                }
                return false;
            }
        };
    
        private void toggle() {
            if (mVisible) {
                hide();
            } else {
                show();
            }
        }
    
        private void hide() {
            // Hide UI first
            ActionBar actionBar = getSupportActionBar();
            if (actionBar != null) {
                actionBar.hide();
            }
            mVisible = false;
    
            // Schedule a runnable to remove the status and navigation bar after a delay
            mHideHandler.removeCallbacks(mShowPart2Runnable);
            mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
        }
    
        private final Runnable mHidePart2Runnable = new Runnable() {
            @SuppressLint("InlinedApi")
            @Override
            public void run() {
                // Delayed removal of status and navigation bar
    
                // Note that some of these constants are new as of API 16 (Jelly Bean)
                // and API 19 (KitKat). It is safe to use them, as they are inlined
                // at compile-time and do nothing on earlier devices.
            }
        };
    
        @SuppressLint("InlinedApi")
        private void show() {
            // Show the system bar
            mVisible = true;
    
            // Schedule a runnable to display UI elements after a delay
            mHideHandler.removeCallbacks(mHidePart2Runnable);
            mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
        }
    
        private final Runnable mShowPart2Runnable = new Runnable() {
            @Override
            public void run() {
                // Delayed display of UI elements
                ActionBar actionBar = getSupportActionBar();
                if (actionBar != null) {
                    actionBar.show();
                }
            }
        };
    
        private final Handler mHideHandler = new Handler();
        private final Runnable mHideRunnable = new Runnable() {
            @Override
            public void run() {
                hide();
            }
        };
    
        /**
         * Schedules a call to hide() in delay milliseconds, canceling any
         * previously scheduled calls.
         */
        private void delayedHide(int delayMillis) {
            mHideHandler.removeCallbacks(mHideRunnable);
            mHideHandler.postDelayed(mHideRunnable, delayMillis);
        }
    }
    

    现在,如果我执行我的代码,那么我会得到一个页面,上面写着“网站不可用”。网站位于 https://www.botec.de/ 无法加载,因为:net::err“缓存未命中”(可以找到此新问题的解决方案) here )

    因此,黑屏和“崩溃”或者更确切地说是关闭应用程序的问题,是因为在创建一个新的空全屏项目之后出现了不必要的代码。