自己编写Android手电筒,支持5.0

2015-4-30 11:38 741 0

摘要: android手电筒原理很简单，就是打开相机的闪光灯。核心的代码就这么多：打开相机设置闪光灯开 ...

关键词： nbsp Camera mParameters android Parameters import Flashlight autoFocus AutoFocusCallbac Activity

android手电筒原理很简单，就是打开相机的闪光灯。核心的代码就这么多：打开相机设置闪光灯开打开预览设置相机的autoFocus [java] view plaincopyprint? Camera camera = Camera.open(); Parameters mParameters = camera.getParameters(); mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH); camera.setParameters(mParameters); camera.startPreview(); camera.autoFocus(new AutoFocusCallback() { public void onAutoFocus(boolean success, Camera camera) { } }); 这几个步骤缺一不可。照网上之前的例子试了，一直不成功。就是因为有些缺了打开预览，有些缺了autoFocus 然后就是设置权限 [html] view plaincopyprint? <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.autofocus" /> <uses-feature android:name="android.hardware.camera.flash" /> 最后贴以下完整的Activity。我这个很简单，create的时候就打开手电筒，屏幕上显示”Flashlight open“，按返回键，关闭并退出应用。 [java] view plaincopyprint?package org.lhc.flashlight; import android.app.Activity; import android.hardware.Camera; import android.hardware.Camera.AutoFocusCallback; import android.hardware.Camera.Parameters; import android.os.Bundle; import android.util.Log; import android.view.KeyEvent; import android.widget.TextView; public class MainActivity extends Activity { private Camera camera = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); this.camera = Camera.open(); if (this.camera != null) { Parameters mParameters = camera.getParameters(); mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH); camera.setParameters(mParameters); camera.startPreview(); camera.autoFocus(new AutoFocusCallback() { public void onAutoFocus(boolean success, Camera camera) { } }); TextView info = (TextView)this.findViewById(R.id.flashlight_info); info.setText("Flashlight open"); } } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { if (this.camera != null) { Parameters mParameters = camera.getParameters(); mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF); camera.setParameters(mParameters); camera.stopPreview(); camera.release(); } Log.i("Flashlight", "exit"); this.finish(); System.exit(0); } return super.onKeyDown(keyCode, event); }

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