Question

我应该使用哪种函数从firebase检索数据到标签的正确语法是什么？

例如，我想将电子邮件和密码检索为in the picture here

我试过这个代码，但它没有用！它在模拟器中找不到任何东西!!

public class MySurfaceThread extends AsyncTask<Void, Void, Void> {


    SurfaceHolder mSurfaceHolder;
    CustomSurfaceView cSurfaceView;


    public MySurfaceThread(SurfaceHolder sh, CustomSurfaceView csv) {
        mSurfaceHolder = sh;
        cSurfaceView = csv;
        x = y = 0;

        cSurfaceView.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                x = event.getX();
                y = event.getY();

                calculateValues(x, y);

                switch (event.getAction() & MotionEvent.ACTION_MASK) {
                    case MotionEvent.ACTION_DOWN:

                        break;
                    case MotionEvent.ACTION_UP:
                        x = y = 0;
                        dx = dy = 0;
                        break;
                    case MotionEvent.ACTION_CANCEL:

                        break;
                    case MotionEvent.ACTION_MOVE:

                        break;
                }

                return true;
            }

            private void calculateValues(float xx, float yy) {
                dx = xx - zeroX;
                dy = yy - zeroY;
                angle = (float)Math.atan(Math.abs(dy/dx));
                hyp = (float)Math.sqrt((dx * dx) + (dy * dy));

                if(hyp > radius) {
                    if(dx > 0 && dy > 0){ //bottom right
                        xx = (zeroX + (radius*(float)Math.cos(angle)));
                        yy = (zeroY + (radius*(float)Math.sin(angle)));
                    }
                    else if(dx > 0 && dy < 0){ //top right
                        xx = (zeroX + (radius*(float)Math.cos(angle)));
                        yy = (zeroY - (radius*(float)Math.sin(angle)));
                    }

                    else if(dx < 0 && dy < 0){ //top left
                        xx = (zeroX - (radius*(float)Math.cos(angle)));
                        yy = (zeroY - (radius*(float)Math.sin(angle)));
                    }

                    else if(dx < 0 && dy > 0) { //bottom left
                        xx = (zeroX - (radius*(float)Math.cos(angle)));
                        yy = (zeroY + (radius*(float)Math.sin(angle)));
                    }
                }

                else {
                    xx = zeroX + dx;
                    yy = zeroY + dy;
                }

                x = xx;
                y = yy;
            }


        });
    }

    @Override
    protected Void doInBackground(Void... params) {
        Canvas canvas = null;

        while (running) {
            try {
                canvas = mSurfaceHolder.lockCanvas();
                synchronized (mSurfaceHolder) {
                    zeroX = canvas.getWidth()/2;
                    zeroY = canvas.getHeight()/2;
                    cSurfaceView.onDraw(canvas, x, y, zeroX, zeroY);
                }
                Thread.sleep(10);
            } catch (InterruptedException e) {

            } finally {
                if (canvas != null) {
                    mSurfaceHolder.unlockCanvasAndPost(canvas);
                }
            }
        }
        return null;
    }
}

Answer 1

试试这个

var ref = Firebase(url:"YOUR_URL_PATH/Users")

ref.observeEventType(.Value, withBlock: { snapshot in
        let m = snapshot.value.objectForKey("Email")as?
        self.EmailLabel.text = m
}, withCancelBlock: { error in
    println(error.description)
})

希望这会对你有帮助......

从Firebase检索数据到标签＆＃39; Swift Project＆＃39;

1 个答案: