关于Android的活动 [英] Regarding Android Activity
本文介绍了关于Android的活动的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我现在面临一个很大的问题涉及到活动。我的情况如下：
我开始活动A，点击一个按钮，然后选择了一个形象的画廊则在 onActivityResult 我叫 startActivity（B）。
现在在我的活动B，在选定的图像已被证明对的ListView 这是显示。
现在在点击一个按钮，我叫 startActivityforResult（录像机类）打开了一个新的活动，这是一个自定义视频录像机的活动。
现在在点击停止按钮活动记录 mediaRecorder 停止，释放和保存视频，然后在的setResult 不言而喻再次活动B插入 onActivityResult（）。
但现在的问题是：
有两种不同的情况下，我在这里找到：
-
第一个是，当我宣布我的录音机类景观：
下面的点击记录类停止按钮，屏幕突然变成黑色和A开始几秒钟活动后。
-
第二个是，当我改变了录音机类的方向为纵向模式：
下面的点击记录课堂活动B停止按钮启动（无黑屏），但之后又几秒钟活性的开始。
还有一件事，我发现在这里：
- 在我替换
startActivityForResult（）与startActivity（）的活动B和从记录的活动我再次呼吁startActivity（B）这表明活动B， 但几秒钟后，同样的b活动重新开始。 在这里一些新的东西发生
- 我相信这是只是因为
MediaRecorder，当我评论从我的记录所有的媒体记录code类则是罚款。
录音机类的我的code是在这里：
公共类录音机延伸活动实现SurfaceHolder.Callback {
/ **第一次创建活动时调用。 * /
@覆盖
公共无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
mediaRecorder =新MediaRecorder（）;
的setContentView（R.layout.recorde）;
initMediaRecorder（）;
定时器=新的Timer（）;
TimerTask的TimerTask的=新的TimerTask（）{
@覆盖
公共无效的run（）{
如果（柜＆LT; = 10）
反++;
// Android的UI获得continouly更新
其他 {
//如果条件满打满计时器将停在这里
mediaRecorder.stop（）;
mediaRecorder.reset（）;
mediaRecorder.release（）;
timer.cancel（）;
Recorder.this.finish（）;
意图I =新的意图（Recorder.this，B.class）;
的setResult（Activity.RESULT_OK，i.putExtra（returnedVideo，strPath中））;
}
}
};
timer.schedule（TimerTask的，1000，1000）;
SurfaceView myVideoView =（SurfaceView）findViewById（R.id.videoview）;
surfaceHolder = myVideoView.getHolder（）;
surfaceHolder.addCallback（本）;
surfaceHolder.setType（SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS）;
为myButton =（按钮）findViewById（R.id.mybutton）;
myButton.setOnClickListener（myButtonOnClickListener）;
}
私人Button.OnClickListener myButtonOnClickListener
=新Button.OnClickListener（）{
公共无效的onClick（查看为arg0）{
// TODO自动生成方法存根
mediaRecorder.stop（）;
mediaRecorder.reset（）;
mediaRecorder.release（）;
timer.cancel（）;
Recorder.this.finish（）;
意图I =新的意图（Recorder.this，B.class）;
的setResult（Activity.RESULT_OK，i.putExtra（returnedVideo，strPath中））;
}};
公共无效surfaceChanged（SurfaceHolder为arg0，诠释ARG1，诠释ARG2，诠释ARG3）{
// TODO自动生成方法存根
}
公共无效surfaceCreated（SurfaceHolder为arg0）{
// TODO自动生成方法存根
prepareMediaRecorder（）;
}
公共无效surfaceDestroyed（SurfaceHolder为arg0）{
// TODO自动生成方法存根
mediaRecorder.stop（）;
mediaRecorder.release（）;
//Recorder.this.finish（）;
}
@覆盖
公共无效onBack pressed（）{
// TODO自动生成方法存根
super.onBack pressed（）;
mediaRecorder.stop（）;
mediaRecorder.release（）;
}
私人无效initMediaRecorder（）{
随机genraotr =新的随机（）;
INT N = 10000;
N = genraotr.nextInt（N）;
mediaRecorder.setAudioSource（MediaRecorder.AudioSource.DEFAULT）;
mediaRecorder.setVideoSource（MediaRecorder.VideoSource.DEFAULT）;
CamcorderProfile camcorderProfile_HQ = CamcorderProfile.get（CamcorderProfile.QUALITY_HIGH）;
mediaRecorder.setProfile（camcorderProfile_HQ）;
mediaRecorder.setOutputFile（/ SD卡/ my_video+ N +MP4。）;
strPath的=/sdcard/my_video"+n+".mp4;
mediaRecorder.setMaxDuration（10000）; //设置最大持续时间10秒。
mediaRecorder.setMaxFileSize（5000000）; //设置最大文件大小为5M
}
私人无效prepareMediaRecorder（）{
mediaRecorder.set previewDisplay（surfaceHolder.getSurface（））;
尝试 {
mediaRecorder prepare（）。
mediaRecorder.start（）;
}赶上（IllegalStateException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
}
}
解决方案
这似乎有一个与你的刻录机类的问题。使用这个code请再试一次：
公共类AndroidVideoCapture延伸活动{
私人相机myCamera;
私人MyCameraSurfaceView myCameraSurfaceView;
私人MediaRecorder mediaRecorder;
按钮myButton的;
SurfaceHolder surfaceHolder;
布尔记录;
公共静态字符串strPath的;
/ **第一次创建活动时调用。 * /
@覆盖
公共无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
记录= FALSE;
的setContentView（R.layout.main）;
//获取相机为preVIEW
myCamera = getCameraInstance（）;
如果（myCamera == NULL）{
Toast.makeText（AndroidVideoCapture.this，
轮不到相机，
Toast.LENGTH_LONG）.show（）;
}
myCameraSurfaceView =新MyCameraSurfaceView（这一点，myCamera）;
的FrameLayout myCamera preVIEW =（的FrameLayout）findViewById（R.id.videoview）;
myCamera preview.addView（myCameraSurfaceView）;
为myButton =（按钮）findViewById（R.id.mybutton）;
myButton.setOnClickListener（myButtonOnClickListener）;
}
Button.OnClickListener myButtonOnClickListener
=新Button.OnClickListener（）{
公共无效的onClick（视图v）{
// TODO自动生成方法存根
如果（录音）{
//停止录制并发行摄像头
mediaRecorder.stop（）; //停止录制
releaseMediaRecorder（）; //释放MediaRecorder对象
意图I =新的意图（AndroidVideoCapture.this，TakeAnotherPhoto.class）;
i.putExtra（returnedVideo，strPath的）;
的setResult（Activity.RESULT_OK，我）;
//保存退出后，
完（）;
}其他{
//发布MediaRecorder开始前摄像头
releaseCamera（）;
如果（！prepareMediaRecorder（））{
Toast.makeText（AndroidVideoCapture.this，
在失败prepareMediaRecorder（）\ N - ！结束 - ，
Toast.LENGTH_LONG）.show（）;
完（）;
}
mediaRecorder.start（）;
记录= TRUE;
myButton.setText（STOP）;
}
}};
私人摄像机getCameraInstance（）{
// TODO自动生成方法存根
相机C = NULL;
尝试 {
C = Camera.open（）; //尝试获取摄像头实例
}
赶上（例外五）{
//相机无法使用（使用或不存在）
}
返回℃; //如果相机是不可用，则返回null
}
私人布尔prepareMediaRecorder（）{
随机genraotr =新的随机（）;
INT N = 10000;
N = genraotr.nextInt（N）;
myCamera = getCameraInstance（）;
mediaRecorder =新MediaRecorder（）;
myCamera.unlock（）;
mediaRecorder.setCamera（myCamera）;
mediaRecorder.setAudioSource（MediaRecorder.AudioSource.CAMCORDER）;
mediaRecorder.setVideoSource（MediaRecorder.VideoSource.CAMERA）;
mediaRecorder.setProfile（CamcorderProfile.get（CamcorderProfile.QUALITY_HIGH））;
mediaRecorder.setOutputFile（/ SD卡/ auction_video+ N +MP4。）;
strPath的=/sdcard/auction_video"+n+".mp4;
mediaRecorder.setMaxDuration（10000）; //设置最大持续时间10秒。
mediaRecorder.setMaxFileSize（5000000）; //设置最大文件大小为5M
mediaRecorder.set previewDisplay（myCameraSurfaceView.getHolder（）getSurface（））;
尝试 {
mediaRecorder prepare（）。
}赶上（IllegalStateException异常E）{
releaseMediaRecorder（）;
返回false;
}赶上（IOException异常E）{
releaseMediaRecorder（）;
返回false;
}
返回true;
}
保护无效的onPause（）{
super.onPause（）;
releaseMediaRecorder（）; //如果您使用的是MediaRecorder，先将它
releaseCamera（）; //在暂停时立即松开相机
}
私人无效releaseMediaRecorder（）{
如果（mediaRecorder！= NULL）{
mediaRecorder.reset（）; //清晰的记录配置
mediaRecorder.release（）; //释放录像机对象
mediaRecorder = NULL;
myCamera.lock（）; //锁定相机以备后用
}
}
私人无效releaseCamera（）{
如果（myCamera！= NULL）{
myCamera.release（）; //释放相机用于其它应用
myCamera = NULL;
}
}
公共类MyCameraSurfaceView扩展了SurfaceView实现SurfaceHolder.Callback {
私人SurfaceHolder mHolder;
私人相机mCamera;
公共MyCameraSurfaceView（上下文的背景下，相机摄像头）{
超（上下文）;
mCamera =摄像头;
//安装SurfaceHolder.Callback所以我们得到通知时，该
//下垫面创建和销毁。
mHolder = getHolder（）;
mHolder.addCallback（本）;
//德precated设置，但在Android上之前的版本3.0所需
mHolder.setType（SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS）;
}
公共无效surfaceChanged（SurfaceHolder持有人，INT格式，诠释权重，
INT高度）{
//如果你的preVIEW可以改变或旋转，把这些事件的关心在这里。
//确保调整或重新格式化之前停止preVIEW。
如果（mHolder.getSurface（）== NULL）{
// preVIEW表面不存在
返回;
}
在进行更改之前//停止preVIEW
尝试 {
mCamera.stop preVIEW（）;
}赶上（例外五）{
//忽略：试图阻止一个不存在的preVIEW
}
//做任何调整大小，旋转或重新格式化这里的变化
//启动preVIEW使用新设置
尝试 {
mCamera.set previewDisplay（mHolder）;
mCamera.start preVIEW（）;
}赶上（例外五）{
}
}
公共无效surfaceCreated（SurfaceHolder持有者）{
// TODO自动生成方法存根
//表面有被创建，现在告诉相机在哪里画preVIEW。
尝试 {
mCamera.set previewDisplay（保持器）;
mCamera.start preVIEW（）;
}赶上（IOException异常E）{
}
}
公共无效surfaceDestroyed（SurfaceHolder持有者）{
// TODO自动生成方法存根
}
}
@覆盖
公共无效onBack pressed（）{
// TODO自动生成方法存根
super.onBack pressed（）;
mediaRecorder.stop（）; //停止录制
releaseMediaRecorder（）; //释放MediaRecorder对象
//保存退出后，
完（）;
}
//公共无效showMessage（标题字符串，字符串的消息，最终的上下文语境）{
// 尝试
// {
// AlertDialog.Builder alt_bld =新AlertDialog.Builder（上下文）;
// alt_bld.setTitle（职称）;
// alt_bld.setMessage（消息）;
// alt_bld.setCancelable（假）;
// alt_bld.setNeutralButton（OK，新DialogInterface.OnClickListener（）{
//
//公共无效的onClick（DialogInterface对话，诠释它）{
// // TODO自动生成方法存根
// dialog.dismiss（）;
//
//意图I =新的意图（AndroidVideoCapture.this，TakeAnotherPhoto.class）;
// i.putExtra（returnedVideo，strPath的）;
//的setResult（Activity.RESULT_OK，我）;
//}
//}）;
// alt_bld.show（）;
//}
//赶上（例外五）{
// // TODO：处理异常
//}
//}
}
让我知道，如果它的工作原理。
感谢
I'm facing a big problem related to Activity. My scenario is as follows:
I starts activity A,clicked on a button then picked an image from the gallery then in onActivityResult I called startActivity(B).
Now in my Activity B that image selected in A has been shown on ListView which is showing.
Now on click of a button I called startActivityforResult(Recorder class) opened a new activity which is a custom video recorder activity.
Now in activity Recorder on clicking stop button mediaRecorder stops, release and save video and then after setResult it goes to again activity B into onActivityResult().
But here is the problem:
Two different cases I found here:
First one is when I declared my Recorder class as Landscape:
Here on clicking stop button in Recorder class my screen goes black and after few seconds activity A starts.
Second one is when I changed orientation of Recorder class to Portrait mode:
Here on clicking stop button in Recorder class activity B starts (no black screen) but again after few seconds activity A starts.
One more thing which I observed here:
- I replaced
startActivityForResult()withstartActivity()in activity B and from Recorder Activity i again calledstartActivity(B)which shows activity B, but here something new happens after few seconds the same activity B starts again. - I am sure this is just because of
MediaRecorderas when I commented all media recorder code from myRecorderclass then it was fine.
My Code of Recorder class is here:
public class Recorder extends Activity implements SurfaceHolder.Callback{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mediaRecorder = new MediaRecorder();
setContentView(R.layout.recorde);
initMediaRecorder();
timer = new Timer();
TimerTask timerTask = new TimerTask() {
@Override
public void run() {
if(counter<=10)
counter++;
//Android UI get Updated continouly
else {
// If condition full filled the timer will stop here
mediaRecorder.stop();
mediaRecorder.reset();
mediaRecorder.release();
timer.cancel();
Recorder.this.finish();
Intent i = new Intent(Recorder.this,B.class);
setResult(Activity.RESULT_OK, i.putExtra("returnedVideo", strPath));
}
}
};
timer.schedule(timerTask, 1000, 1000);
SurfaceView myVideoView = (SurfaceView)findViewById(R.id.videoview);
surfaceHolder = myVideoView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
myButton = (Button)findViewById(R.id.mybutton);
myButton.setOnClickListener(myButtonOnClickListener);
}
private Button.OnClickListener myButtonOnClickListener
= new Button.OnClickListener(){
public void onClick(View arg0) {
// TODO Auto-generated method stub
mediaRecorder.stop();
mediaRecorder.reset();
mediaRecorder.release();
timer.cancel();
Recorder.this.finish();
Intent i = new Intent(Recorder.this,B.class);
setResult(Activity.RESULT_OK, i.putExtra("returnedVideo", strPath));
}};
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder arg0) {
// TODO Auto-generated method stub
prepareMediaRecorder();
}
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
mediaRecorder.stop();
mediaRecorder.release();
//Recorder.this.finish();
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
super.onBackPressed();
mediaRecorder.stop();
mediaRecorder.release();
}
private void initMediaRecorder(){
Random genraotr = new Random();
int n = 10000;
n = genraotr.nextInt(n);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
CamcorderProfile camcorderProfile_HQ = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
mediaRecorder.setProfile(camcorderProfile_HQ);
mediaRecorder.setOutputFile("/sdcard/my_video"+n+".mp4");
strPath = "/sdcard/my_video"+n+".mp4";
mediaRecorder.setMaxDuration(10000); // Set max duration 10 sec.
mediaRecorder.setMaxFileSize(5000000); // Set max file size 5M
}
private void prepareMediaRecorder(){
mediaRecorder.setPreviewDisplay(surfaceHolder.getSurface());
try {
mediaRecorder.prepare();
mediaRecorder.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
解决方案
It seems there is a problem with your recorder class. Please try once using this code:
public class AndroidVideoCapture extends Activity{
private Camera myCamera;
private MyCameraSurfaceView myCameraSurfaceView;
private MediaRecorder mediaRecorder;
Button myButton;
SurfaceHolder surfaceHolder;
boolean recording;
public static String strPath;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
recording = false;
setContentView(R.layout.main);
//Get Camera for preview
myCamera = getCameraInstance();
if(myCamera == null){
Toast.makeText(AndroidVideoCapture.this,
"Fail to get Camera",
Toast.LENGTH_LONG).show();
}
myCameraSurfaceView = new MyCameraSurfaceView(this, myCamera);
FrameLayout myCameraPreview = (FrameLayout)findViewById(R.id.videoview);
myCameraPreview.addView(myCameraSurfaceView);
myButton = (Button)findViewById(R.id.mybutton);
myButton.setOnClickListener(myButtonOnClickListener);
}
Button.OnClickListener myButtonOnClickListener
= new Button.OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
if(recording){
// stop recording and release camera
mediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
Intent i = new Intent(AndroidVideoCapture.this,TakeAnotherPhoto.class);
i.putExtra("returnedVideo", strPath);
setResult(Activity.RESULT_OK, i);
//Exit after saved
finish();
}else{
//Release Camera before MediaRecorder start
releaseCamera();
if(!prepareMediaRecorder()){
Toast.makeText(AndroidVideoCapture.this,
"Fail in prepareMediaRecorder()!\n - Ended -",
Toast.LENGTH_LONG).show();
finish();
}
mediaRecorder.start();
recording = true;
myButton.setText("STOP");
}
}};
private Camera getCameraInstance(){
// TODO Auto-generated method stub
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
private boolean prepareMediaRecorder(){
Random genraotr = new Random();
int n = 10000;
n = genraotr.nextInt(n);
myCamera = getCameraInstance();
mediaRecorder = new MediaRecorder();
myCamera.unlock();
mediaRecorder.setCamera(myCamera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mediaRecorder.setOutputFile("/sdcard/auction_video"+n+".mp4");
strPath = "/sdcard/auction_video"+n+".mp4";
mediaRecorder.setMaxDuration(10000); // Set max duration 10 sec.
mediaRecorder.setMaxFileSize(5000000); // Set max file size 5M
mediaRecorder.setPreviewDisplay(myCameraSurfaceView.getHolder().getSurface());
try {
mediaRecorder.prepare();
} catch (IllegalStateException e) {
releaseMediaRecorder();
return false;
} catch (IOException e) {
releaseMediaRecorder();
return false;
}
return true;
}
protected void onPause() {
super.onPause();
releaseMediaRecorder(); // if you are using MediaRecorder, release it first
releaseCamera(); // release the camera immediately on pause event
}
private void releaseMediaRecorder(){
if (mediaRecorder != null) {
mediaRecorder.reset(); // clear recorder configuration
mediaRecorder.release(); // release the recorder object
mediaRecorder = null;
myCamera.lock(); // lock camera for later use
}
}
private void releaseCamera(){
if (myCamera != null){
myCamera.release(); // release the camera for other applications
myCamera = null;
}
}
public class MyCameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback{
private SurfaceHolder mHolder;
private Camera mCamera;
public MyCameraSurfaceView(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceChanged(SurfaceHolder holder, int format, int weight,
int height) {
// 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 (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// make any resize, rotate or reformatting changes here
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
}
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
super.onBackPressed();
mediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
//Exit after saved
finish();
}
// public void showMessage(String title, String message, final Context context){
// try
// {
// AlertDialog.Builder alt_bld = new AlertDialog.Builder(context);
// alt_bld.setTitle(title);
// alt_bld.setMessage(message);
// alt_bld.setCancelable(false);
// alt_bld.setNeutralButton("OK", new DialogInterface.OnClickListener() {
//
// public void onClick(DialogInterface dialog, int which) {
// // TODO Auto-generated method stub
// dialog.dismiss();
//
// Intent i = new Intent(AndroidVideoCapture.this,TakeAnotherPhoto.class);
// i.putExtra("returnedVideo", strPath);
// setResult(Activity.RESULT_OK, i);
// }
// });
// alt_bld.show();
// }
// catch (Exception e) {
// // TODO: handle exception
// }
// }
}
and let me know if it works.
Thanks
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