Android webview 如何禁止双击缩放

public class MyWebView extends WebView {    private long last_time = 0L;    public MyWebView(Context context) {        super(context);    }    public MyWebView(Context context, AttributeSet attrs) {        super(context, attrs);    }    @Override    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()) {            case MotionEvent.ACTION_DOWN:                long current_time = System.currentTimeMillis();                long d_time = current_time - last_time;//                System.out.println(d_time);                if (d_time < 300) {                    last_time = current_time;                    return true;                } else {                    last_time = current_time;                }                break;        }        return super.onTouchEvent(event);    }}