停止<select>跳转到信件按

时间：2018-03-16 21:35:30

标签： html

＆lt; select size =“5”＆gt;   ＆LT;选项＆gt;一种与LT; /选项＆GT;   ＆LT;选项＆GT; b将/选项＆GT;   ＆LT;选项＆GT;℃下/选项＆GT;   ＆LT;选项＆GT; d＆LT; /选项＆GT;   ＆LT;选项＆GT; e控制/选项＆GT; ＆LT; /选择＆GT; 当然，当我按a，b，c，d或e时，这会跳转到选项，作为第一个字母。我需要禁用它，最好不要通过Javascript（不是必需的）。 真的没有办法关掉这个按键跳转到字母选项吗？ 谢谢！

4 个答案:

答案 0 :(得分：2)

没有JavaScript，你无法做到这一点。

使用JavaScript，您需要为$("select").on("keypress", function (event) { event.preventDefault(); event.stopPropagation(); }); 事件添加事件处理程序，以防止默认行为并停止传播。

使用jQuery：

$("select")

请注意keypress将选择所有选择的输入，并且您最终会为所有输入添加此<select id="mySelect" size="5"> <option>a</option> <option>b</option> <option>c</option> <option>d</option> <option>e</option> </select> var select = document.getElementById('mySelect'); select.addEventListener ("keypress", function (event) { event.preventDefault(); event.stopPropagation(); }); 。

没有jQuery：

package <your package>;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;

/**
 * Zooming view.
 */
public class ZoomView extends FrameLayout {

public ZoomView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
}

public ZoomView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
}

public ZoomView(final Context context) {
    super(context);
}

/**
 * Zooming view listener interface.
 * 
 * @author karooolek
 * 
 */
public interface ZoomViewListener {

    void onZoomStarted(float zoom, float zoomx, float zoomy);

    void onZooming(float zoom, float zoomx, float zoomy);

    void onZoomEnded(float zoom, float zoomx, float zoomy);
}

// zooming
float zoom = 1.0f;
float maxZoom = 2.0f;
float smoothZoom = 1.0f;
float zoomX, zoomY;
float smoothZoomX, smoothZoomY;
private boolean scrolling; // NOPMD by karooolek on 29.06.11 11:45

// minimap variables
private boolean showMinimap = false;
private int miniMapColor = Color.WHITE;
private int miniMapHeight = -1;
private String miniMapCaption;
private float miniMapCaptionSize = 10.0f;
private int miniMapCaptionColor = Color.WHITE;

// touching variables
private long lastTapTime;
private float touchStartX, touchStartY;
private float touchLastX, touchLastY;
private float startd;
private boolean pinching;
private float lastd;
private float lastdx1, lastdy1;
private float lastdx2, lastdy2;

// drawing
private final Matrix m = new Matrix();
private final Paint p = new Paint();

// listener
ZoomViewListener listener;

private Bitmap ch;

public float getZoom() {
    return zoom;
}

public float getMaxZoom() {
    return maxZoom;
}

public void setMaxZoom(final float maxZoom) {
    if (maxZoom < 1.0f) {
        return;
    }

    this.maxZoom = maxZoom;
}

public void setMiniMapEnabled(final boolean showMiniMap) {
    this.showMinimap = showMiniMap;
}

public boolean isMiniMapEnabled() {
    return showMinimap;
}

public void setMiniMapHeight(final int miniMapHeight) {
    if (miniMapHeight < 0) {
        return;
    }
    this.miniMapHeight = miniMapHeight;
}

public int getMiniMapHeight() {
    return miniMapHeight;
}

public void setMiniMapColor(final int color) {
    miniMapColor = color;
}

public int getMiniMapColor() {
    return miniMapColor;
}

public String getMiniMapCaption() {
    return miniMapCaption;
}

public void setMiniMapCaption(final String miniMapCaption) {
    this.miniMapCaption = miniMapCaption;
}

public float getMiniMapCaptionSize() {
    return miniMapCaptionSize;
}

public void setMiniMapCaptionSize(final float size) {
    miniMapCaptionSize = size;
}

public int getMiniMapCaptionColor() {
    return miniMapCaptionColor;
}

public void setMiniMapCaptionColor(final int color) {
    miniMapCaptionColor = color;
}

public void zoomTo(final float zoom, final float x, final float y) {
    this.zoom = Math.min(zoom, maxZoom);
    zoomX = x;
    zoomY = y;
    smoothZoomTo(this.zoom, x, y);
}

public void smoothZoomTo(final float zoom, final float x, final float y) {
    smoothZoom = clamp(1.0f, zoom, maxZoom);
    smoothZoomX = x;
    smoothZoomY = y;
    if (listener != null) {
        listener.onZoomStarted(smoothZoom, x, y);
    }
}

public ZoomViewListener getListener() {
    return listener;
}

public void setListner(final ZoomViewListener listener) {
    this.listener = listener;
}

public float getZoomFocusX() {
    return zoomX * zoom;
}

public float getZoomFocusY() {
    return zoomY * zoom;
}

@Override
public boolean dispatchTouchEvent(final MotionEvent ev) {
    // single touch
    if (ev.getPointerCount() == 1) {
        processSingleTouchEvent(ev);
    }

    // // double touch
    if (ev.getPointerCount() == 2) {
        processDoubleTouchEvent(ev);
    }

    // redraw
    getRootView().invalidate();
    invalidate();

    return true;
}

private void processSingleTouchEvent(final MotionEvent ev) {

    final float x = ev.getX();
    final float y = ev.getY();

    final float w = miniMapHeight * (float) getWidth() / getHeight();
    final float h = miniMapHeight;
    final boolean touchingMiniMap = x >= 10.0f && x <= 10.0f + w
            && y >= 10.0f && y <= 10.0f + h;

    if (showMinimap && smoothZoom > 1.0f && touchingMiniMap) {
        processSingleTouchOnMinimap(ev);
    } else {
        processSingleTouchOutsideMinimap(ev);
    }
}

private void processSingleTouchOnMinimap(final MotionEvent ev) {
    final float x = ev.getX();
    final float y = ev.getY();

    final float w = miniMapHeight * (float) getWidth() / getHeight();
    final float h = miniMapHeight;
    final float zx = (x - 10.0f) / w * getWidth();
    final float zy = (y - 10.0f) / h * getHeight();
    smoothZoomTo(smoothZoom, zx, zy);
}

private void processSingleTouchOutsideMinimap(final MotionEvent ev) {
    final float x = ev.getX();
    final float y = ev.getY();
    float lx = x - touchStartX;
    float ly = y - touchStartY;
    final float l = (float) Math.hypot(lx, ly);
    float dx = x - touchLastX;
    float dy = y - touchLastY;
    touchLastX = x;
    touchLastY = y;

    switch (ev.getAction()) {
    case MotionEvent.ACTION_DOWN:
        touchStartX = x;
        touchStartY = y;
        touchLastX = x;
        touchLastY = y;
        dx = 0;
        dy = 0;
        lx = 0;
        ly = 0;
        scrolling = false;
        break;

        case MotionEvent.ACTION_MOVE:
            if (scrolling || (smoothZoom > 1.0f && l > 30.0f)) {
                if (!scrolling) {
                    scrolling = true;
                    ev.setAction(MotionEvent.ACTION_CANCEL);
                    super.dispatchTouchEvent(ev);
                }
                smoothZoomX -= dx / zoom;
                smoothZoomY -= dy / zoom;
                return;
            }
            break;

        case MotionEvent.ACTION_OUTSIDE:
        case MotionEvent.ACTION_UP:

            // tap
            if (l < 30.0f) {
                // check double tap
                if (System.currentTimeMillis() - lastTapTime < 500) {
                    if (smoothZoom == 1.0f) {
                        smoothZoomTo(maxZoom, x, y);
                    } else {
                        smoothZoomTo(1.0f, getWidth() / 2.0f,
                            getHeight() / 2.0f);
                    }
                    lastTapTime = 0;
                    ev.setAction(MotionEvent.ACTION_CANCEL);
                    super.dispatchTouchEvent(ev);
                    return;
                }

                lastTapTime = System.currentTimeMillis();

                performClick();
            }
            break;

        default:
            break;
        }

        ev.setLocation(zoomX + (x - 0.5f * getWidth()) / zoom, zoomY
            + (y - 0.5f * getHeight()) / zoom);

        ev.getX();
        ev.getY();

        super.dispatchTouchEvent(ev);
    }

    private void processDoubleTouchEvent(final MotionEvent ev) {
        final float x1 = ev.getX(0);
        final float dx1 = x1 - lastdx1;
        lastdx1 = x1;
        final float y1 = ev.getY(0);
        final float dy1 = y1 - lastdy1;
        lastdy1 = y1;
        final float x2 = ev.getX(1);
        final float dx2 = x2 - lastdx2;
        lastdx2 = x2;
        final float y2 = ev.getY(1);
        final float dy2 = y2 - lastdy2;
        lastdy2 = y2;

        // pointers distance
        final float d = (float) Math.hypot(x2 - x1, y2 - y1);
        final float dd = d - lastd;
        lastd = d;
        final float ld = Math.abs(d - startd);

        Math.atan2(y2 - y1, x2 - x1);
        switch (ev.getAction()) {
        case MotionEvent.ACTION_DOWN:
            startd = d;
            pinching = false;
            break;

        case MotionEvent.ACTION_MOVE:
            if (pinching || ld > 30.0f) {
                pinching = true;
                final float dxk = 0.5f * (dx1 + dx2);
                final float dyk = 0.5f * (dy1 + dy2);
                smoothZoomTo(Math.max(1.0f, zoom * d / (d - dd)), zoomX - dxk
                    / zoom, zoomY - dyk / zoom);
            }

            break;

        case MotionEvent.ACTION_UP:
        default:
        pinching = false;
        break;
        }

        ev.setAction(MotionEvent.ACTION_CANCEL);
        super.dispatchTouchEvent(ev);
    }

    private float clamp(final float min, final float value, final float max) {
        return Math.max(min, Math.min(value, max));
    }

    private float lerp(final float a, final float b, final float k) {
    return a + (b - a) * k;
    }

    private float bias(final float a, final float b, final float k) {
    return Math.abs(b - a) >= k ? a + k * Math.signum(b - a) : b;
    }

    @Override
    protected void dispatchDraw(final Canvas canvas) {

        // do zoom
        zoom = lerp(bias(zoom, smoothZoom, 0.05f), smoothZoom, 0.2f);
        smoothZoomX = clamp(0.5f * getWidth() / smoothZoom, smoothZoomX,
            getWidth() - 0.5f * getWidth() / smoothZoom);
        smoothZoomY = clamp(0.5f * getHeight() / smoothZoom, smoothZoomY,
            getHeight() - 0.5f * getHeight() / smoothZoom);

        zoomX = lerp(bias(zoomX, smoothZoomX, 0.1f), smoothZoomX, 0.35f);
        zoomY = lerp(bias(zoomY, smoothZoomY, 0.1f), smoothZoomY, 0.35f);
        if (zoom != smoothZoom && listener != null) {
            listener.onZooming(zoom, zoomX, zoomY);
        }

        final boolean animating = Math.abs(zoom - smoothZoom) > 0.0000001f
                || Math.abs(zoomX - smoothZoomX) > 0.0000001f
                || Math.abs(zoomY - smoothZoomY) > 0.0000001f;

        // nothing to draw
        if (getChildCount() == 0) {
            return;
        }

        // prepare matrix
        m.setTranslate(0.5f * getWidth(), 0.5f * getHeight());
        m.preScale(zoom, zoom);
        m.preTranslate(
                -clamp(0.5f * getWidth() / zoom, zoomX, getWidth() - 0.5f
                    * getWidth() / zoom),
                -clamp(0.5f * getHeight() / zoom, zoomY, getHeight() - 0.5f
                    * getHeight() / zoom));

        // get view
        final View v = getChildAt(0);
        m.preTranslate(v.getLeft(), v.getTop());

        // get drawing cache if available
        if (animating && ch == null && isAnimationCacheEnabled()) {
            v.setDrawingCacheEnabled(true);
            ch = v.getDrawingCache();
        }

        // draw using cache while animating
        if (animating && isAnimationCacheEnabled() && ch != null) {
            p.setColor(0xffffffff);
            canvas.drawBitmap(ch, m, p);
        } else { // zoomed or cache unavailable
            ch = null;
            canvas.save();
            canvas.concat(m);
            v.draw(canvas);
            canvas.restore();
        }

        // draw minimap
        if (showMinimap) {
            if (miniMapHeight < 0) {
                miniMapHeight = getHeight() / 4;
            }

            canvas.translate(10.0f, 10.0f);

            p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
            final float w = miniMapHeight * (float) getWidth() / getHeight();
            final float h = miniMapHeight;
            canvas.drawRect(0.0f, 0.0f, w, h, p);

            if (miniMapCaption != null && miniMapCaption.length() > 0) {
                p.setTextSize(miniMapCaptionSize);
                p.setColor(miniMapCaptionColor);
                p.setAntiAlias(true);
                canvas.drawText(miniMapCaption, 10.0f,
                        10.0f + miniMapCaptionSize, p);
                p.setAntiAlias(false);
            }

            p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
            final float dx = w * zoomX / getWidth();
            final float dy = h * zoomY / getHeight();
            canvas.drawRect(dx - 0.5f * w / zoom, dy - 0.5f * h / zoom, dx
                    + 0.5f * w / zoom, dy + 0.5f * h / zoom, p);

            canvas.translate(-10.0f, -10.0f);
        }

        // redraw
        // if (animating) {
        getRootView().invalidate();
        invalidate();
        // }
    }
}

工作小提琴：https://jsfiddle.net/ep3xfyc8/9/

稍后编辑：存在一种无需JavaScript即可实现此目的的解决方案。请参阅Lee Kowalkowski的回复。

答案 1 :(得分：2)

你 可以不用 JavaScript

使用Zero-Width Non Joiner字符为每个选项添加前缀。

<label for="select">Select:</label>
<select size="5" id="select">
  <option>&zwnj;a</option>
  <option>&zwnj;b</option>
  <option>&zwnj;c</option>
  <option>&zwnj;d</option>
  <option>&zwnj;e</option>
</select>

如果要在HTTP请求中提交，则浏览器应忽略&zwnj;字符。无论如何，每个选项都应该有自己的value属性用于表单提交，并且您不需要将&zwnj;字符放入选项值。

答案 2 :(得分：0)

来源：https://stackoverflow.com/a/1227324/9505307

投票结束 接受

有人给我留下了正确答案，然后由于某种原因将其删除了，所以这就是：

SELECT s.*, COUNT(*) as count from stats AS s 
   INNER JOIN users as u on u.client_id=s.client_id
   GROUP BY client_id

好奇心......你为什么要这样做？

答案 3 :(得分：0)

这是@ razvan-dimitru提出的改编，但将JS保持在最低限度。在某种程度上，您只需要为此解决方案添加标记：

<select onkeyup='event.preventDefault(); event.stopPropagation();'>
  <option>a</option>
  <option>b</option>
  <option>c</option>
  <option>d</option>
  <option>e</option>
</select>

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