TextureView必须工作在硬件加速条件, 否则什么都不执行.
因为需要 android:hardwareAccelerated=”true”或者
Window w = activity.getWindow(); w.setFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
如果是在Service里面，直接在AndroidManifest设置会不起作用，只能直接对Window设置flag
WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED
看官方文档
A TextureView can be used to display a content stream. Such a content stream can for instance be a video or an OpenGL scene. The content stream can come from the application's process as well as a remote process.
TextureView can only be used in a hardware accelerated window. When rendered in software, TextureView will draw nothing.
Unlike SurfaceView , TextureView does not create a separate window but behaves as a regular View. This key difference allows a TextureView to be moved, transformed, animated, etc. For instance, you can make a TextureView semi-translucent by calling myView.setAlpha(0.5f).
Using a TextureView is simple: all you need to do is get its SurfaceTexture . The SurfaceTexture can then be used to render content. The following example demonstrates how to render the camera preview into a TextureView:
public class LiveCameraActivity extends Activity implements TextureView.SurfaceTextureListener {
private Camera mCamera;
private TextureView mTextureView;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mTextureView = new TextureView(this);
mTextureView.setSurfaceTextureListener(this);
setContentView(mTextureView);
}
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
mCamera = Camera.open();
try {
mCamera.setPreviewTexture(surface);
mCamera.startPreview();
} catch (IOException ioe) {
// Something bad happened
}
}
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
// Ignored, Camera does all the work for us
}
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
mCamera.stopPreview();
mCamera.release();
return true;
}
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
// Invoked every time there's a new Camera preview frame
}
}
A TextureView's SurfaceTexture can be obtained either by invoking getSurfaceTexture() or by using a TextureView.SurfaceTextureListener . It is important to know that a SurfaceTexture is available only after the TextureView is attached to a window (and onAttachedToWindow() has been invoked.) It is therefore highly recommended you use a listener to be notified when the SurfaceTexture becomes available.
It is important to note that only one producer can use the TextureView. For instance, if you use a TextureView to display the camera preview, you cannot use lockCanvas() to draw onto the TextureView at the same time.
以下转载自: https://blog.csdn.net/u010775683/article/details/78364141
几个注意事项:
1、TextureView是Android 4.0之后加入的，低版本么这个类。TextureView必须工作在开启硬件加速的环境中，也即配置文件里Activity的设置项里：android:hardwareAccelerated="true" 默认的这个属性就是true，因此不用再写了。但如果写成false，可以看到onSurfaceTextureAvailable()这个回调就进不来了；
2、有两点跟Surfaceview不同。第一，TextureView创建过程中没有进到onSurfaceTextureSizeChanged()这个函数里。而SurfaceView在创建过程中，从无到有的时候会进到大小发生变化回调里。第二，onSurfaceTextureUpdated()这个函数每上来一帧数据，这块就进来一次。这是跟Surfaceview相比，最伟大的一个地方。通过这个接口，可以将上来的SurfaceTexture送给OpenGL再去处理。这个回调是实时的，而非用Camera的PreviewCallback这种2次回调的方式。从时间看，基本上每32ms左右上来一帧数据，即每秒30帧，跟本手机的Camera的性能吻合。
3、Camera再执行startPreview时必须保证TextureView的SurfaceTexture上来了，如果因为一些性能原因onSurfaceTextureAvailable()这个回调上不来就开预览，就开不了的。如果发生这种情况，就在onSurfaceTextureAvailable()回调里执行open和startPreview操作，保证万无一失。
4、SurfaceTexture和TextureView的关系:
如果说TextureView是一幅画的话，那SurfaceTexture就是画布，真正渲染的载体是SurfaceTexture。
5、TextureView可以像一般View执行各种变化，其中有个textureView.setAlpha(1.0f);默认不写这句话，它的alpha也是1.0f,即不透明。如果设成透明0.0f，可以看到啥都看不到了，这一点跟Surfaceview刚好相反。Surfaceview的SurfaceHolder一般要设一下Transparent即透明。但TextureView因为是个view，任何一个png的照片透明度设成0肯定啥都看不到。
6、如果认为预览个Camera这就是TextureView和SurfaceTexture的使命的话，就大错特错了，真正用意是和OpenGL无缝连接。
参考:
https://blog.csdn.net/WeLoveSunFlower/article/details/53423992
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