android - 无法使闪光灯连续闪烁并在单击按钮时停止

Question

我试图让手电筒在连续按下按钮时闪烁，直到再次按下按钮。闪光灯持续闪烁，但我无法停止闪烁，因为应用程序卡住了。这是我的代码:

public void Buts1(View view) {
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    long blinkDelay = 50;//delay in ms
    if(textView.getText().toString().equals("ON")){
       boolean s=false;
        while (textView.getText().toString().equals("ON")){
            if(s){
                try {
                    String cameraId = cameraManager.getCameraIdList()[0];
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        cameraManager.setTorchMode(cameraId, true);
                    }
                } catch (CameraAccessException e) {
                }
                s=false;
            }else{
                try {
                    String cameraId = cameraManager.getCameraIdList()[0];
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        cameraManager.setTorchMode(cameraId, false);
                    }
                } catch (CameraAccessException e) {
                }
                s=true;
            }
            try {
                Thread.sleep(blinkDelay);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
} 

Answer 1

我相信您在这里卡住了 UI 线程。此外，我没有看到任何将 textView 文本设置为“OFF”的内容。

我稍微修改了您的代码，假定 textView 以文本“OFF”开头，并在您单击按钮时更改为“ON”。再次单击该按钮会将 textView 文本设置为“OFF”并关闭闪烁。这是通过在单独的线程而不是 UI 线程上工作的。

        button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
            Thread flashThread = new Thread(new Runnable() {
                @Override
                public void run() {
                    boolean s=false;
                    long blinkDelay = 50;//delay in ms
                    while (textView.getText().toString().equals("ON")){
                        if(s){
                            try {
                                String cameraId = cameraManager.getCameraIdList()[0];
                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                    cameraManager.setTorchMode(cameraId, true);
                                }
                            } catch (CameraAccessException e) {
                            }
                            s=false;
                        }else{
                            try {
                                String cameraId = cameraManager.getCameraIdList()[0];
                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                    cameraManager.setTorchMode(cameraId, false);
                                }
                            } catch (CameraAccessException e) {
                            }
                            s=true;
                        }
                        try {
                            Thread.sleep(blinkDelay);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }


                }
            });
            if(textView.getText().toString().equalsIgnoreCase("OFF")){
                textView.setText("ON");
                flashThread.start();
            }else{
                flashThread.interrupt();
                try {
                    String cameraId = cameraManager.getCameraIdList()[0];
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        cameraManager.setTorchMode(cameraId, false);
                    }
                } catch (CameraAccessException e) {
                }
                textView.setText("OFF");
            }
        }
    });