小编jnt*_*jns的帖子

我的Android应用程序的一段代码遇到了一些麻烦.我NullPointerException在尝试设置ImageView对象的背景时不断得到.

这是代码:

public View getView(int position, View view, ViewGroup parent) {
    ImageView imageView;
    if (view == null) {
        imageView = new ImageView(mContext);
    } else {
        imageView = (ImageView) view;
    }
    imageView.setTag(position);
    return imageView;
}

private OnItemClickListener itemClickListener = new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {

        ImageView imageView;
        //Variable i, here, is from a for loop.
        imageView = (ImageView)v.findViewWithTag(i);
        //I get a NullPointerException at the next line, "Log.d"
        Log.d("View …

我想添加 PreferenceFragment一个FragmentPagerAdapter.

我的课程延伸FragmentActivity,我尝试过FragmentTransaction,如下所示,以及尝试添加到容器,似乎无法得到任何工作.没有错误被抛出,实际上没有任何反应.

主要活动:

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

    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);
}

activity_main.xml中:

<android.support.v4.view.ViewPager 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
</android.support.v4.view.ViewPager>

我的选项菜单选择:

android.app.FragmentManager fm;
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.menu_settings:
        JJSettings settings = new JJSettings();
        fm = getFragmentManager();
        FragmentTransaction fragTrans = fm.beginTransaction();
        // I also tried `replace()` here as well. Same 'nothing happens' result.
        fragTrans.add(settings, …

我的应用程序有点问题.我刚刚实现了捏缩放,但是当我捏缩放时,图像不会在2点的中心缩放,如下图所示.图像1是我的手指在捏之前的位置,图像2是显示它没有像我应该的那样在我的手指中心缩放.

图1与图2:

这是我的代码:

        package com.jpiionefourone.guitarimage;

    import android.content.Context;
    import android.graphics.Canvas;
    import android.graphics.drawable.Drawable;
    import android.util.AttributeSet;
    import android.view.MotionEvent;
    import android.view.ScaleGestureDetector;
    import android.view.View;

    public class MultiTouchView extends View {
        private Drawable mIcon;
        private float mPosX;
        private float mPosY;

        private float mLastTouchX;
        private float mLastTouchY;

        private static final int INVALID_POINTER_ID = -1;

        // The ‘active pointer’ is the one currently moving our object.
        private int mActivePointerId = INVALID_POINTER_ID;

        private ScaleGestureDetector mScaleDetector;
        private float mScaleFactor = 1.f;


        public MultiTouchView(Context context) {
            this(context, null, 0);
        }

        public …

有没有办法点击子菜单中的隐藏值.我希望能够做类似的事情

driver.findElement(protractor.By.xpath('/html/body/div/div/a')).mouseover.then(function() {
    ptor.findElement(protractor.By.className('name').getText().then(function(result) {
        expect(result).toBe('Me');
    });
});

当菜单项不可见时,或者我们目前是否受此限制.如果这是不可能的,目前有办法解决这个问题.

单击操作栏中的中间图标时,会出现一个下拉菜单:

我如何制作其中一个？RelativeLayouts？

Eclipse当我在模拟器和手机上遇到强制关闭错误时,我正在使用IDE 编写一个Android应用程序.我只是改变了布局,strings.xml并且我没有在eclipse中显示错误,当我尝试在eclipse模拟器或智能手机上打开应用程序时,它仍然说"强制关闭".这是我的布局,main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<Button
    android:id="@+id/connect"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/ButtonConnect" />

<Button
    android:id="@+id/device"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/connect"
    android:text="@string/ButtonDevice" />

<ImageView
    android:id="@+id/joystick_hulle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:contentDescription="@string/joystickhulle"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_marginBottom="30dp"
    android:layout_marginLeft="30dp"
    android:src="@drawable/joystick_bg" />

<ImageView
    android:id="@+id/joystick"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:contentDescription="@string/joystick"
    android:layout_alignLeft="@+id/joystick_hulle"
    android:layout_alignTop="@+id/joystick_hulle"
    android:layout_marginLeft="17dp"
    android:layout_marginTop="17dp"
    android:src="@drawable/joystick" />

<Button
    android:id="@+id/M1P"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/device"
    android:layout_marginLeft="25dp"
    android:layout_toRightOf="@+id/device"
    android:text="@string/Pfeilhoch" />

<Button
    android:id="@+id/M2P"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/M1P"
    android:layout_alignBottom="@+id/M1P"
    android:layout_marginLeft="25dp"
    android:layout_toRightOf="@+id/M1P"
    android:text="@string/Pfeilhoch" />

<Button
    android:id="@+id/M3P"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/M2P"
    android:layout_alignBottom="@+id/M2P"
    android:layout_marginLeft="25dp"
    android:layout_toRightOf="@+id/M2P"
    android:text="@string/Pfeilhoch" />

<Button
    android:id="@+id/M4P" …

我已编写此代码在屏幕上打开surfaceview上的前置摄像头,但是当你点击按钮时我想用前置摄像头录制视频.

这段代码崩溃了.我已经为相机使用了两个不同的变量,但我找不到我的错误:( ..我已经按照谷歌指南.

public class MainActivity extends Activity {
    public static final int MEDIA_TYPE_VIDEO = 2;

    private Camera mCamera;
    private CameraPreview mPreview;
    public static final int MEDIA_TYPE_IMAGE = 1;
    protected static final String TAG = null;

    private MediaRecorder mMediaRecorder; 
    private Camera mCamerafront;
    private boolean isRecording = false;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Button captureButton = (Button) findViewById(id.button_capture);
        mCamera = getCameraInstance();

        // Create our Preview view and set it as the content of our activity.
        mPreview = …

我在尝试通过SQL语句将最近的位置返回给用户时遇到问题.为了测试我使用完全相同的坐标,这里是我所拥有的:

SQL:

SELECT  `companies`.`customerName` , 
    (3959 * 
        ACOS(
            COS(
                RADIANS(37.367485) * COS(RADIANS(`locations`.`gps_lat`)) * 
                COS(
                    RADIANS(`locations`.`gps_lng`) - RADIANS(-77.399994) + 
                    SIN(RADIANS(37.367485)) * SIN(RADIANS(`locations`.`gps_lat`))
                )
            )
        )
    )
AS  `distance` 
FROM  `locations` 
JOIN  `companies` ON  `locations`.`co_id` 
HAVING  `distance` > 25
ORDER BY distance
LIMIT 0 , 10

结果:

| customerName  | distance           |
| SOME COMPANY  | 1914.41747964854   |

locations 表值:

gps_lat   | gps_lng
37.367485 | -77.399994

我使用了谷歌的例子,我检查了几次公式,我似乎无法想出我出错的地方.任何帮助表示赞赏.

编辑:
因为我知道自己在做什么似乎有些困惑:

的>被取代的,得到的结果,1914很明显大于25.

这个应用程序是将用户坐标从Android应用程序传递到我们的Web服务器.纬度和经度将从$_GET值中提取,并从我们的Web服务器MYSQL数据库中的公司进行交叉引用.

上面的语法只是我在Mysql …

我正在使用exifInterface进行照片旋转问题代码如下:面对从相机捕获的图像方向问题.

• 从文件创建位图

Bitmap b = BitmapFactory.decodeFile(imagePath);

• 通过将位图缩放到适当的级别来调整位图的大小

int width = b.getWidth();
int height = b.getHeight();
int newWidth = 150;
int newHeight = 150;
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
// Bitmap resizedBitmap = Bitmap.createBitmap(b, 0, 0, width, height, matrix, true);
// resizedBitmap.compress(Bitmap.CompressFormat.JPEG, 70, out);

• 处理图像的方向

 ExifInterface exif = new ExifInterface(imagePath);
    String orientation = exif.getAttribute(ExifInterface.TAG_ORIENTATION);
    if (orientation.equals(ExifInterface.ORIENTATION_NORMAL)) {
            // Do nothing. The original image is fine. …

我有以下TabHost布局:

<?xml version="1.0" encoding="iso-8859-1"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_margin="0dp"
    android:padding="0dp" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_margin="0dp"
        android:background="@drawable/main_app_background"
        android:orientation="vertical"
        android:padding="0dp" >

        <ImageView
            android:id="@+id/logo"
            android:layout_width="fill_parent"
            android:layout_height="@dimen/site_logo_height"
            android:layout_margin="0dp"
            android:background="@color/tab_subtitle_background"
            android:padding="0dp"
            android:src="@drawable/barlogo" />

        <FrameLayout
            android:id="@+id/tab_subtitle"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_margin="0dp"
            android:gravity="center"
            android:padding="0dp" />

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_gravity="center"
            android:layout_margin="0dp"
            android:layout_weight="99"
            android:padding="0dp" />

        <Button
            android:id="@+id/btn_save"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="15dp"
            android:layout_marginTop="7dp"
            android:focusableInTouchMode="true"
            android:imeOptions="actionNext"
            android:tag="done"
            android:text="Ok" />

        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_margin="0dp"
            android:layout_weight="1"
            android:padding="0dp" />
    </LinearLayout>

</TabHost>

问题是,当软键盘出现时,Button和TabWidget都向上移动.

我的目标是将TabWidget保持在底部(软键盘下方),然后让Ok按钮向上移动(在键盘顶部).可能吗？

提前致谢!