【Android Studio】SurfaceView

Android Studio

SurfaceView

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MainSV.java

public class MainSV extends SurfaceView implements SurfaceHolder.Callback, Runnable {
    private SurfaceHolder sh;
    private Thread th;
    private boolean flag;
    private Paint paint;
    private int FPS;
    private float scalerw,scalerh;
    private Canvas canvas;

    public MainSV(Context context){
        super(context);
        sh=this.getHolder();
        sh.addCallback(this);
        paint=new Paint();
        paint.setColor(Color.WHITE);
        setFocusable(true);
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        flag=true;
        th=new Thread(this);
        th.start();
    }
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        scalerw=(float)width/720;
        scalerh=(float)height/1280;
    }
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        flag=false;
    }
    public void logicSV(){
        //logic
    }
    public void drawSV(){
        try{
            canvas=sh.lockCanvas();
            if(canvas!=null){
                canvas.save();
                canvas.scale(scalerw,scalerh);
                canvas.drawText("FPS:"+String.valueOf(FPS)+"  "+String.valueOf(scalerw)+"*"+String.valueOf(scalerh),0,30,paint);
                canvas.restore();
            }
        } catch (Exception e){
        } finally {
            if(canvas!=null)
                sh.unlockCanvasAndPost(canvas);
        }
    }
    @Override
    public void run() {
        while(flag){
            long tinterval=System.currentTimeMillis();
            logicSV();
            drawSV();
            tinterval=System.currentTimeMillis()-tinterval;
            try{
                if(tinterval<33){
                    FPS=30;
                    Thread.sleep(33-tinterval);
                }else{
                    FPS=1000/(int)tinterval;
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

drawSV()中：

內容	位置
文本	canvas.scale()和canvas.restore()之間
圖片	圖片無需縮放，圖片位置需要*scalerw(h)

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MainActivity.java

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        MainSV mainsv=new MainSV(this);
        setContentView(mainsv);
    }
    @Override
    protected void onResume(){
        if(getRequestedOrientation()!= ActivityInfo.SCREEN_ORIENTATION_PORTRAIT)
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        super.onResume();
    }
}

屏幕	ActivityInfo.
豎屏	SCREEN_ORIENTATION_PORTRAIT
橫屏	SCREEN_ORIENTATION_LANDSCAPE