我从方法surfaceChanged()调用Camera.setParameters()时出现RuntimeException错误。我看到了同一个问题的其他职位,但没有找到一个明确的解决方案: Issue with setting the parameters to camera在setChanged()中传递的宽度和高度不受setParameters()支持?
我的问题是:
为什么要surfaceChanged()来surfaceCreated之后称为()?这是直观的(至少对我来说)在surfaceCreated()中启动预览,只是停止它并重新启动surfaceChanged()中的另一个。
当第一次调用surfaceChanged()时,什么决定传入的宽度和高度?正如前面提到的文章中所建议的,并且在我的实验中进行了验证,Camera.setParameters()不一定支持这些值。请参阅下面的代码片段和日志信息。
在调用surfaceChanged()之前,有没有办法确保Camera.setParameters()支持宽度和高度值?可以在surfaceChanged()中添加代码来确保。例如,可以将w和h与所有支持的预览尺寸进行比较,并将其更改为最接近的支持值。但是,这样做会妨碍性能。
以下列表是我的代码片段和LogCat输出。日志记录信息表明surfaceChanged()中的Camera.setParameters()导致错误。如果我注释掉setParameters()被调用的那一行,我不会再看到错误消息。
[编辑:我正在测试亚马逊Kindle Fire HD。 Android版本是4.0.3,API 15]
代码片段:
public void surfaceCreated(SurfaceHolder holder) {
// Log & debug
Log.d(TAG, "surfaceCreated() is called");
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "surfaceCreated(): " + e.getMessage());
}
if (mHolder.getSurface() == null) {
Log.d(TAG, "surfaceCreated(): preview surface does not exist yet!");
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Log & debug
Log.d(TAG, "surfaceDestroyed() is called");
// Stop preview and release camera
if (holder.getSurface() != null) {
mCamera.stopPreview();
//mCamera.release(); //should we release camera here?
//mCamera = null;
}
else {
Log.d(TAG, "surfaceDestroyed(): preview surface does not exist");
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Log and debug
Log.d(TAG, "surfaceChanged() is called with width = " + w);
Log.d(TAG, "surfaceChanged() is called with height = " + h);
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (holder.getSurface() == null) {
Log.d(TAG, "surfaceChanged(): preview surface does not exist");
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
Log.d(TAG, "surfaceChanged(): tried to stop a non-existent preview " + e.getMessage());
}
// set preview size and make any resize, rotate or
// reformatting changes here
Camera.Parameters params = mCamera.getParameters();
List<Size> mSizes = params.getSupportedPreviewSizes();
// list all 25 supported preview sizes
// i==25 will cause an "IndexOutofBoundsException"
for (int i=0; i<25; i++) {
Size mSize = mSizes.get(i);
if (mSize == null) break;
Log.d(TAG, "surfaceChanged() i = " + i);
Log.d(TAG, "surfaceChanged() preview width = " + mSize.width);
Log.d(TAG, "surfaceChanged() preview height = " + mSize.height);
}
Size mSize = mSizes.get(0);
if(mSize != null) { //make sure we don't pull a NullException.
if (w > mSize.width) w = mSize.width;
if (h > mSize.height) h = mSize.height;
params.setPreviewSize(w, h); //set the size, since we know it.
}
mCamera.setParameters(params); //set the parameters now.
// start preview with new settings
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "surfaceChanged() restart preview " + e.getMessage());
}
}
logcat的输出:那你可能会得到这样的问题
02-13 10:46:08.113: D/CameraPreview(2886): surfaceCreated() is called
02-13 10:46:08.496: D/CameraPreview(2886): surfaceChanged() is called with width = 1072
02-13 10:46:08.496: D/CameraPreview(2886): surfaceChanged() is called with height = 705
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 0
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 1280
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 1
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 960
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 2
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 800
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 3
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 576
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 4
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 5
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 768
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 576
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 6
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 640
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 7
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 320
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 240
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 8
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 352
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 288
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 9
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 240
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 160
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 10
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 176
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 144
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 11
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 160
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 120
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 12
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 128
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 96
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 13
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 1280
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 14
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 800
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 15
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 576
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 16
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 576
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 768
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 17
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 720
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 18
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 480
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 640
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 19
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 288
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 352
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 20
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 240
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 320
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 21
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 240
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 160
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 22
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 144
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 176
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 23
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 120
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 160
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() i = 24
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview width = 96
02-13 10:46:08.941: D/CameraPreview(2886): surfaceChanged() preview height = 128
02-13 10:46:08.957: D/AndroidRuntime(2886): Shutting down VM
02-13 10:46:08.957: W/dalvikvm(2886): threadid=1: thread exiting with uncaught exception (group=0x40a6c1f8)
02-13 10:46:08.965: E/AndroidRuntime(2886): FATAL EXCEPTION: main
02-13 10:46:08.965: E/AndroidRuntime(2886): java.lang.RuntimeException: setParameters failed
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.hardware.Camera.native_setParameters(Native Method)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.hardware.Camera.setParameters(Camera.java:1295)
02-13 10:46:08.965: E/AndroidRuntime(2886): at com.xyz.camera.CameraPreview.surfaceChanged(CameraPreview.java:109)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.SurfaceView.updateWindow(SurfaceView.java:544)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.SurfaceView.access$000(SurfaceView.java:81)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:169)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:590)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1630)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2462)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.os.Handler.dispatchMessage(Handler.java:99)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.os.Looper.loop(Looper.java:137)
02-13 10:46:08.965: E/AndroidRuntime(2886): at android.app.ActivityThread.main(ActivityThread.java:4486)
02-13 10:46:08.965: E/AndroidRuntime(2886): at java.lang.reflect.Method.invokeNative(Native Method)
02-13 10:46:08.965: E/AndroidRuntime(2886): at java.lang.reflect.Method.invoke(Method.java:511)
02-13 10:46:08.965: E/AndroidRuntime(2886): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-13 10:46:08.965: E/AndroidRuntime(2886): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-13 10:46:08.965: E/AndroidRuntime(2886): at dalvik.system.NativeStart.main(Native Method)
哪个API是你编译和你测试哪个设备? – Raigex 2013-02-13 19:44:01
@Raigex:很好的问题。亚马逊Kindle Fire HD(android 4.0.3,API 15)。 – hubeir 2013-02-13 19:50:36
任何人都知道答案问题1? – hubeir 2013-02-13 23:20:12