问题
在开发Android应用程序时,经常会有登录界面,无非是输入用户名、密码进行登录。当输入框获取焦点时,会弹出软键盘进行输入,如果输入框和登录按钮布局在整个布局文件的中间或靠下,势必会被软键盘遮挡,让人十分郁闷。网络上的解决方法无非也就那么三种:
第一、将登录框放在布局文件的顶端,软键盘不会遮挡;这种方案虽然能解决问题,但相当不灵活;
第二、在布局文件中根节点处加入ScrollView控件;
第三、这是我今天要讲的内容
首先,继承RelativeLayout,获取当前屏幕高度,实现onMesure、onSizeChanged方法;
其次,为自定义的Layout添加视图偏移的监听器
最后、在Activity当中实现监听
代码
- public class InputMethodRelativeLayout extends RelativeLayout {
- private int width;
- private int height;
- private int screenHeight;
- private boolean sizeChanged = false;
- private OnSizeChangedListener onSizeChangedListener;
- public InputMethodRelativeLayout(Context context, AttributeSet attrs,
- int defStyle) {
- super(context, attrs, defStyle);
- Display localDisplay = ((Activity)context).getWindowManager().getDefaultDisplay();
- screenHeight = localDisplay.getHeight();
- // TODO Auto-generated constructor stub
- }
- public InputMethodRelativeLayout(Context context, AttributeSet attrs) {
- super(context, attrs);
- // TODO Auto-generated constructor stub
- }
- public InputMethodRelativeLayout(Context context) {
- super(context);
- // TODO Auto-generated constructor stub
- }
- @Override
- protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
- // TODO Auto-generated method stub
- this.width = widthMeasureSpec;
- this.height = heightMeasureSpec;
- super.onMeasure(widthMeasureSpec, heightMeasureSpec);
- }
- @Override
- protected void onSizeChanged(int w, int h, int oldw, int oldh) {
- // TODO Auto-generated method stub
- //监听不为空、宽度不变、当前高度与历史高度不为0
- if(this.onSizeChangedListener != null && w == oldw && h != 0 && oldh != 0){
- if(h >= oldh || (Math.abs(h - oldh) <= 1 * this.screenHeight / 4)){
- sizeChanged = false;
- }else if(h <= oldh || (Math.abs(h - oldh) <= 1 * this.screenHeight / 4)){
- sizeChanged = true;
- }
- this.onSizeChangedListener.onSizeChange(sizeChanged);
- measure(this.width - w + getWidth(), this.height - h + getHeight());
- }
- }
- /**
- * @Title: setOnSizeChangedListener
- * @Description: 为当前布局设置onSizeChanged监听器
- * @param sizeChangedListener
- * @return void
- */
- public void setOnSizeChangedListener(OnSizeChangedListener sizeChangedListener) {
- this.onSizeChangedListener = sizeChangedListener;
- }
- public abstract interface OnSizeChangedListener{
- public abstract void onSizeChange(boolean flag);
- }
在Activity中实现OnSizeChangedListener,原理是设置该布局的paddingTop属性来控制子View的偏移,如下:
- public class OALogin extends BaseActivity implements InputMethodRelativeLayout.OnSizeChangedListener{
- @InjectView(R.id.loginpage)
- private InputMethodRelativeLayout layout;
- @Inject
- private InputMethodManager inputMethodManager;
- private float density;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // TODO Auto-generated method stub
- super.onCreate(savedInstanceState);
- setContentView(R.layout.login_page);
- getSupportActionBar().hide();
- density = getResources().getDisplayMetrics().density;
- layout.setOnSizeChangedListener(this);
- }
- @Override
- public void onSizeChange(boolean flag) {
- // TODO Auto-generated method stub
- if(flag){
- layout.setPadding(0, -159, 0, 0);
- }else
- layout.setPadding(0, 0, 0, 0);
- }
- @Override
- public boolean onTouchEvent(MotionEvent event) {
- // TODO Auto-generated method stub
- if(event.getAction() == MotionEvent.ACTION_UP){
- inputMethodManager.hideSoftInputFromWindow(getWindow().getDecorView().getWindowToken(),0);
- }
- return super.onTouchEvent(event);
- }
在AndroidManifest.xml中注册该Activity,需要注意的是:必须为该Activity设置android:windowSoftInputMode="adjustResize"属性,当windowSoftInputMode为adjustResiz时,Layout才会调用protected void onSizeChanged(int w, int h, int oldw, int oldh)这个方法。
俗话说,无图无真相,直接上图(借助了QQ2012的登录界面)
各位体会下吧!