我对 Android 开发还很陌生,因此非常感谢任何帮助。
我有一个应用程序,它使用光传感器读取光量并将其显示在屏幕上。我正在android studio上开发它。标题下方是一个 textView,是一个 imageView,后面还有两个 TextView 。无论我尝试哪种布局,当我有 imageView 时,应用程序都会崩溃。一旦我删除 imageView,应用程序就会毫无问题地运行。我的图像位于可绘制包中(希望这是正确的术语)并且是 JPEG(根据文档,这是受支持的文件类型)。
此外,我了解到我的 textView 项目之一设置为等于“Light”,而不是指向字符串。我知道这不是我应该做的事情,我仍在开发该应用程序。
请帮我找出我做错了什么。我感谢所有的帮助和时间!
<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="#ffffffff">
<TextView android:text="@string/title" android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textIsSelectable="false"
android:textSize="@dimen/abc_text_size_headline_material"
android:textColor="#ff2db81a"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/light_available"
android:text="Sensor"
android:layout_marginBottom="35dp"
android:layout_above="@+id/light_reading"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/light_reading"
android:text="Light"
android:layout_marginBottom="43dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />
<ImageView
android:layout_width="300dp"
android:layout_height="300dp"
android:id="@+id/imageView"
android:layout_above="@+id/light_available"
android:layout_centerInParent="true"
android:layout_margin="10dp"
android:src="@drawable/homeplant" />
这是 Java...
public class MainActivity extends ActionBarActivity {
TextView textLightIsAvailable, textLightReading;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textLightIsAvailable = (TextView)findViewById(R.id.light_available);
textLightReading = (TextView)findViewById(R.id.light_reading);
SensorManager mySensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
Sensor LightSensor = mySensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
if(LightSensor != null){
textLightIsAvailable.setText("You Have a Sensor!");
mySensorManager.registerListener(LightSensorListener, LightSensor, SensorManager.SENSOR_DELAY_NORMAL);
}
else{
textLightIsAvailable.setText("You Don't Have a Sensor!");
}
}
private final SensorEventListener LightSensorListener= new SensorEventListener(){
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType() == Sensor.TYPE_LIGHT){
textLightReading.setText("LIGHT: " + event.values[0]);
}
}
};
更新:2015 年 3 月 10 日:我也尝试了两种不同的虚拟设备,但出现与物理设备相同的错误。 logcat 仅显示(我取出了时间戳/我的包名称,因为它在此处的格式看起来如何)...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ waiting for debugger to settle...
I/System.out﹕ debugger has settled (1433)
再次感谢。
编辑:2015 年 3 月 12 日
我的 JRE 版本是 - 1.6.0_65-B14-466.1 11M4716 x86_64 Android Studio 版本 - 1.1.0
最佳答案
我认为你必须写
android:layout_above="@id/light_available"
而不是
android:layout_above="@+id/light_available"
我不知道如何使用layout_above,但是看到@+id两次很奇怪。
编辑 1: 正如我在评论中所说
- @id/someId 引用项目中现有的 ID
- @+id/someId 在您的项目中创建一个新 ID
我认为你必须将代码更改为
<RelativeLayout
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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="#ffffffff">
<TextView android:text="@string/title" android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textIsSelectable="false"
android:textSize="@dimen/abc_text_size_headline_material"
android:textColor="#ff2db81a"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/light_available"
android:text="Sensor"
android:layout_marginBottom="35dp"
android:layout_above="@id/light_reading"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/light_reading"
android:text="Light"
android:layout_marginBottom="43dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />
<ImageView
android:layout_width="300dp"
android:layout_height="300dp"
android:id="@+id/imageView"
android:layout_above="@id/light_available"
android:layout_centerInParent="true"
android:layout_margin="10dp"
android:src="@drawable/homeplant" />
如果这个答案不起作用,here是一个有替代想法的线程。 (您会注意到 @id 与 android:layout_above 的使用)
编辑2: 这是一个新代码(我测试了这个代码,它对我有用)。
Under the title, which is a textView, is an imageView, followed by two more text views.
<RelativeLayout
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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="#ffffffff">
<TextView
android:id="@+id/textView"
android:text="@string/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textIsSelectable="false"
android:textSize="@dimen/abc_text_size_headline_material"
android:textColor="#ff2db81a"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<ImageView
android:id="@+id/imageView"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_below="@id/textView"
android:layout_margin="10dp"
android:src="@drawable/homeplant" />
<TextView
android:id="@+id/light_available"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Sensor"
android:layout_below="@id/imageView"
android:layout_marginBottom="35dp"
android:layout_centerHorizontal="true" />
<TextView
android:id="@+id/light_reading"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Light"
android:layout_marginBottom="43dp"
android:layout_alignParentBottom="true"
android:layout_below="@id/light_available"
android:layout_centerHorizontal="true" />
</RelativeLayout>
按照您想要的显示顺序放置元素会更容易。在这种情况下,您还可以使用 LinearLayout。这是代码
<LinearLayout
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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="#ffffffff"
android:orientation="vertical">
<TextView
android:id="@+id/textView"
android:text="@string/title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textIsSelectable="false"
android:textSize="@dimen/abc_text_size_headline_material"
android:textColor="#ff2db81a"
android:gravity="center"/>
<ImageView
android:id="@+id/imageView"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_below="@id/textView"
android:layout_margin="10dp"
android:src="@drawable/homeplant"
android:layout_gravity="center"/>
<TextView
android:id="@+id/light_available"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Sensor"
android:layout_below="@id/imageView"
android:layout_marginBottom="35dp"
android:gravity="center" />
<TextView
android:id="@+id/light_reading"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Light"
android:layout_marginBottom="43dp"
android:layout_alignParentBottom="true"
android:layout_below="@id/light_available"
android:layout_centerHorizontal="true"
android:gravity="center"/>
</LinearLayout>
编辑3:
public class MainActivity extends ActionBarActivity implements SensorEventListener {
TextView textLightIsAvailable, textLightReading;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textLightIsAvailable = (TextView) findViewById(R.id.light_available);
textLightReading = (TextView) findViewById(R.id.light_reading);
SensorManager mySensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
Sensor lightSensor = mySensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
if (lightSensor != null) {
textLightIsAvailable.setText("You Have a Sensor!");
mySensorManager.registerListener(this, lightSensor, SensorManager.SENSOR_DELAY_NORMAL);
} else {
textLightIsAvailable.setText("You Don't Have a Sensor!");
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_LIGHT) {
textLightReading.setText("LIGHT: " + event.values[0]);
}
}
}
关于android - ImageView 导致崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28954584/