我正在尝试制作一个在 Galaxy Nexus 上运行的闪光灯应用程序。我知道您需要实现 SurfaceHolder.Callback。但是当我这样做时,应用程序正在编译和运行,没有错误。但是 LED 根本没有打开,并且应用程序在按下切换按钮 3 次后崩溃。
public class MainActivity extends Activity implements SurfaceHolder.Callback {
Camera cam;
public static SurfaceHolder mHolder;
public static SurfaceView preview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
preview = (SurfaceView) findViewById(R.id.PREVIEW);
mHolder = preview.getHolder();
cam = Camera.open();
try {
cam.setPreviewDisplay(mHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ToggleButton toggle = (ToggleButton) findViewById(R.id.toggleButton1);
final TextView text = (TextView) findViewById(R.id.textView1);
text.setText("Flash Light");
toggle.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
// TODO Auto-generated method stub
if(isChecked) {
text.setText("Flash Light is ON");
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();
} else {
text.setText("Flash Light is OFF");
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
cam.setParameters(p);
cam.stopPreview();
cam.release();
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
mHolder = holder;
try {
cam.setPreviewDisplay(mHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
cam.stopPreview();
mHolder = null;
}
}
编辑: list
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.flashlight"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.FLASHLIGHT"/>
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.flash" />
<uses-feature android:name="android.hardware.camera.Parameters" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" android:debuggable="true">
<activity
android:name="com.example.flashlight.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
已回答 :
我发现在我需要在我的 SurfaceView 下添加的 activity_main.xml 中的最后一行:
activity_main.xml
<SurfaceView
android:id="@+id/PREVIEW"
android:layout_width="1dip"
android:layout_height="1dip"
android:visibility="visible" />
最佳答案
检查 flashModes 是否可用。也让你Camera mCamera static
否则当方向改变时,它会丢失相机实例。
public static void FlashOn(Camera mCamera)
{
//Get Camera Params for customisation
Camera.Parameters parameters = mCamera.getParameters();
//Check Whether device supports AutoFlash, If you YES then set AutoFlash
List<String> flashModes = parameters.getSupportedFlashModes();
if (flashModes.contains(android.hardware.Camera.Parameters.FLASH_MODE_TORCH))
{
parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
}
else if(flashModes.contains(Parameters.FLASH_MODE_ON))
{
parameters.setFlashMode(Parameters.FLASH_MODE_ON);
}
mCamera.setParameters(parameters);
mCamera.startPreview();
}
public static void FlashOff(Camera mCamera)
{
//Get Camera Params for customisation
Camera.Parameters parameters = mCamera.getParameters();
//Check Whether device supports AutoFlash, If you YES then set AutoFlash
List<String> flashModes = parameters.getSupportedFlashModes();
if (flashModes.contains(android.hardware.Camera.Parameters.FLASH_MODE_OFF))
{
parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
}
mCamera.setParameters(parameters);
mCamera.startPreview();
}
关于android - 按下切换按钮 3 次后,闪光灯 Android 应用程序崩溃,并且 LED 永远不会亮起,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14785504/