在项目中有时会遇到在一个ListView中item中含有EditText和其他控件的一些列问题,这里就针对ListView中EditText焦点丢失、自动调键盘、保存数据以及滚动冲突的问题简单的介绍并总结一下,希望可以帮助大家:
一.相关布局文件和类文件:
1.activity布局
2.item的布局edittext_item
3.EditText的圆角矩形背景shape_edittext
4.MainActivity
public class MainActivity extends Activity {
private static final String TAG = "zbw";
private static final int DATA_CAPACITY = 20;
private ListView mListView;
private List mList = new ArrayList(DATA_CAPACITY);
private MyAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = (ListView) findViewById(R.id.list_view);
//填充数据
for(int i = 0; i < DATA_CAPACITY; i++) {
mList.add("" + i);
}
//设置Adapter
mAdapter = new MyAdapter(this, mList);
mListView.setAdapter(mAdapter);
}
}
5.MyAdapter
public class MyAdapter extends BaseAdapter {
private ViewHolder mViewHolder;
private LayoutInflater mLayoutInflater;
private List mList;
public MyAdapter(Context context, List list) {
mLayoutInflater = LayoutInflater.from(context);
mList = list;
}
@Override
public int getCount() {
return mList.size();
}
@Override
public Object getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
mViewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.edittext_item, null);
mViewHolder.mTextView = (TextView) convertView.findViewById(R.id.text_view);
mViewHolder.mEditText = (EditText) convertView.findViewById(R.id.edit_text);
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder) convertView.getTag();
}
if (position <= 9) {
mViewHolder.mTextView.setText("0" + (position));
} else {
mViewHolder.mTextView.setText("" + (position));
}
mViewHolder.mEditText.setText(mList.get(position));
return convertView;
}
static final class ViewHolder {
TextView mTextView;
EditText mEditText;
}
}
(在edittext中输入完内容后,隐藏软键盘时,原来输入到edittext中的内容消失了就可以使用下面的方法解决)点击ListView中的某一条目的时候应该能明显看出来ListView移动了一下。软键盘弹出的时候会重新绘制界面,因此ListView进行了一次重新绘制,重新走了一边getView方法,生成了一个新的EditText,而之前展示光标的EditText被销毁,所以才造成了EditText的焦点丢失。
焦点丢失是因为ListView的重绘导致的,我们可以定义一个变量mTouchItemPosition来记录用户触碰的EditText的位置,然后在getView方法中去判断当前的position是否和用户触碰的位置相等,如果相等则让其获得焦点,否则清除焦点。而mTouchItemPosition的值可以在EditText的OnTouch事件中获取。
6.解决焦点问题处理:
//定义成员变量mTouchItemPosition,用来记录手指触摸的EditText的位置
private int mTouchItemPosition = -1;
...
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
mViewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.edittext_item, null);
mViewHolder.mTextView = (TextView) convertView.findViewById(R.id.text_view);
mViewHolder.mEditText = (EditText) convertView.findViewById(R.id.edit_text);
mViewHolder.mEditText.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
//注意,此处必须使用getTag的方式,不能将position定义为final,写成mTouchItemPosition = position
mTouchItemPosition = (Integer) view.getTag();
return false;
}
});
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder) convertView.getTag();
}
if (position <= 9) {
mViewHolder.mTextView.setText("0" + (position));
} else {
mViewHolder.mTextView.setText("" + (position));
}
mViewHolder.mEditText.setText(mList.get(position));
mViewHolder.mEditText.setTag(position);
if (mTouchItemPosition == position) {
mViewHolder.mEditText.requestFocus();
mViewHolder.mEditText.setSelection(mViewHolder.mEditText.getText().length());
} else {
mViewHolder.mEditText.clearFocus();
}
return convertView;
}
上述代码是解决焦点丢失问题,下面来看看保存数据问题:
首先让我们来分析一下怎么保存EditText中的数据。其实保存数据比较简单,我们只需要做两步就可以了,第一步我们需要拿到EditText变化之后的数据;第二步我们将这些数据替换掉之前的就大功告成了。
再次对MyAdapter类进行修改,而用于TextWatcher的afterTextChanged方法中获取不到当前position,所以我们需要新建一个内部类MyTextWatcher实现TextWatcher接口并持有一个position,其次在ViewHolder中需要持有一个MyTextWatcher的引用来动态更新其position的值:
7.保存数据处理:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
mViewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.edittext_item, null);
mViewHolder.mTextView = (TextView) convertView.findViewById(R.id.text_view);
mViewHolder.mEditText = (EditText) convertView.findViewById(R.id.edit_text);
mViewHolder.mEditText.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
//注意,此处必须使用getTag的方式,不能将position定义为final,写成mTouchItemPosition = position
mTouchItemPosition = (Integer) view.getTag();
return false;
}
});
// 让ViewHolder持有一个TextWathcer,动态更新position来防治数据错乱;不能将position定义成final直接使用,必须动态更新
mViewHolder.mTextWatcher = new MyTextWatcher();
mViewHolder.mEditText.addTextChangedListener(mViewHolder.mTextWatcher);
mViewHolder.updatePosition(position);
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder) convertView.getTag();
//动态更新TextWathcer的position
mViewHolder.updatePosition(position);
}
if (position <= 9) {
mViewHolder.mTextView.setText("0" + (position));
} else {
mViewHolder.mTextView.setText("" + (position));
}
mViewHolder.mEditText.setText(mList.get(position));
mViewHolder.mEditText.setTag(position);
if (mTouchItemPosition == position) {
mViewHolder.mEditText.requestFocus();
mViewHolder.mEditText.setSelection(mViewHolder.mEditText.getText().length());
} else {
mViewHolder.mEditText.clearFocus();
}
return convertView;
}
static final class ViewHolder {
TextView mTextView;
EditText mEditText;
MyTextWatcher mTextWatcher;
//动态更新TextWathcer的position
public void updatePosition(int position) {
mTextWatcher.updatePosition(position);
}
}
class MyTextWatcher implements TextWatcher {
//由于TextWatcher的afterTextChanged中拿不到对应的position值,所以自己创建一个子类
private int mPosition;
public void updatePosition(int position) {
mPosition = position;
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void afterTextChanged(Editable s) {
mList.set(mPosition, s.toString());
}
};
8.解决滚动冲突问题:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
mViewHolder = new ViewHolder();
convertView = mLayoutInflater.inflate(R.layout.edittext_item, null);
mViewHolder.mTextView = (TextView) convertView.findViewById(R.id.text_view);
mViewHolder.mEditText = (EditText) convertView.findViewById(R.id.edit_text);
mViewHolder.mEditText.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
//注意,此处必须使用getTag的方式,不能将position定义为final,写成mTouchItemPosition = position
mTouchItemPosition = (Integer) view.getTag();
//触摸的是EditText并且当前EditText可以滚动则将事件交给EditText处理;否则将事件交由其父类处理
if ((view.getId() == R.id.edit_text && canVerticalScroll((EditText)view))) {
view.getParent().requestDisallowInterceptTouchEvent(true);
if (event.getAction() == MotionEvent.ACTION_UP) {
view.getParent().requestDisallowInterceptTouchEvent(false);
}
}
return false;
}
});
// 让ViewHolder持有一个TextWathcer,动态更新position来防治数据错乱;不能将position定义成final直接使用,必须动态更新
mViewHolder.mTextWatcher = new MyTextWatcher();
mViewHolder.mEditText.addTextChangedListener(mViewHolder.mTextWatcher);
mViewHolder.updatePosition(position);
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder) convertView.getTag();
//动态更新TextWathcer的position
mViewHolder.updatePosition(position);
}
if (position <= 9) {
mViewHolder.mTextView.setText("0" + (position));
} else {
mViewHolder.mTextView.setText("" + (position));
}
mViewHolder.mEditText.setText(mList.get(position));
mViewHolder.mEditText.setTag(position);
if (mTouchItemPosition == position) {
mViewHolder.mEditText.requestFocus();
mViewHolder.mEditText.setSelection(mViewHolder.mEditText.getText().length());
} else {
mViewHolder.mEditText.clearFocus();
}
return convertView;
}
/**
* EditText竖直方向是否可以滚动
* @param editText 需要判断的EditText
* @return true:可以滚动 false:不可以滚动
*/
private boolean canVerticalScroll(EditText editText) {
//滚动的距离
int scrollY = editText.getScrollY();
//控件内容的总高度
int scrollRange = editText.getLayout().getHeight();
//控件实际显示的高度
int scrollExtent = editText.getHeight() - editText.getCompoundPaddingTop() -editText.getCompoundPaddingBottom();
//控件内容总高度与实际显示高度的差值
int scrollDifference = scrollRange - scrollExtent;
if(scrollDifference == 0) {
return false;
}
return (scrollY > 0) || (scrollY < scrollDifference - 1);
}
9.EditText自动调起键盘问题:
1).当一个ListView的item中含有抢占焦点的控件的时候,我们通常在item的布局中加上这样一句:
android:descendantFocusability=”blocksDescendants”
防止抢占焦点,大多数情况下都能够解决问题,但是如果是EditText的时候,就很坑了,你会发现软件盘都不能够弹出,更别说输入文字了,要解决这个问题,就是让点击EditText的时候,item最外层不拦截点击事件就ok了,点解item的时候,在拦截点击事件也同样ok了:
mHolder.edtInput.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
((ViewGroup) v.getParent())
.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
return false;
}
});
这个是EditText的时候的处理
setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
这个很关键,而且是在OnTouchListener中执行的,因为在Android中View的触摸事件传递中,View的OnTouchListener调用是早于其他事件的,而且返回值false,代表目前事件没有被消耗,继续向下传递,不影响后续事件的处理(这里不影响EditText其他事件的处理)
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
((ViewGroup) v)
.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
Toast.makeText(mContext, "点击了" + mDatas.get(position), Toast.LENGTH_SHORT).show();
}
});
下面来看看适配器的主要逻辑:
public class NormalAdapter extends ArrayAdapter {
private List mDatas;
private Context mContext;
public NormalAdapter(Context context, List objects) {
super(context, R.layout.activity_list, objects);
mDatas = objects;
mContext = context;
}
@Override
public View getView(final int position, View convertView,
final ViewGroup parent) {
Log.e("tag", parent.toString());
Holder mHolder = null;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(
R.layout.item_group, null);
mHolder = new Holder();
mHolder.tvTitle = (TextView) convertView
.findViewById(R.id.tvGroupTitle);
mHolder.edtInput = (EditText) convertView
.findViewById(R.id.edtGroupContent);
convertView.setTag(mHolder);
} else {
mHolder = (Holder) convertView.getTag();
}
mHolder.tvTitle.setText(mDatas.get(position));
mHolder.edtInput.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
((ViewGroup) v.getParent())
.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
return false;
}
});
convertView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
((ViewGroup) v)
.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
Toast.makeText(mContext, "点击了" + mDatas.get(position), Toast.LENGTH_SHORT).show();
return false;
}
});
return convertView;
}
private static final class Holder {
TextView tvTitle;
EditText edtInput;
}
}
2).在开发过程中,我们经常会碰到Activity中包含EditText控件时会自动弹出虚拟键盘的情形,其实这是由于EditText自动获得焦点的缘故,只要让EditText失去焦点就行了,解决办法如下:
a.在Manifest.xml文件中相应的Activity下添加如下代码即可:
android:windowSoftInputMode=”stateHidden”
b.让EditText失去焦点,用EditText的clearFocus即可:
EditText edit = (EditText)findViewById(R.id.edit);
edit.clearFocus();
c.强制隐藏Android输入法窗口
EditText edit = (EditText)findViewById(R.id.edit);
InputMethodManager imm =
(InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(edit.getWindowToken(), 0);
d.EditText始终不弹出虚拟键盘
EditText edit = (EditText)findViewById(R.id.edit);
edit.setInputType(InputType.TYPE_NULL);
但有时,我们确实是想让EditText自动获得焦点并弹出软键盘,在设置了EditText自动获得焦点后,软件盘不会弹出。注意:此时是由于刚跳到一个新的界面,界面未加载完全而无法弹出软键盘。此时应该适当的延迟弹出软键盘,如500毫秒(保证界面的数据加载完成,如果500毫秒仍未弹出,则延长至1000毫秒)。可以在EditText后面加上一段代码,实例代码如下:
Timer timer = new Timer();
timer.schedule(new TimerTask() {
public void run() {
InputMethodManager inputManager = (InputMethodManager) editText.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
inputManager.showSoftInput(editText, 0);
}
}, 500);
也可以给activity配置加入属性android:windowSoftInputMode=”adjustResize”。
3).设置EditText自动获取焦点并弹出输入法
// 获取编辑框焦点
editText.setFocusable(true);
//打开软键盘
InputMethodManager imm = (InputMethodManager)MainActivity.this.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);
//关闭软键盘
imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
4).方法四:
InputMethodManager imm = (InputMethodManager) getApplicationContext().getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);
private void listenerSoftInput() {
final View activityRootView = findViewById(R.id.baojia);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
int heightDiff = activityRootView.getRootView()
.getHeight() - activityRootView.getHeight();
if (heightDiff > 100) { // 如果高度差超过100像素,就很有可能是有软键盘...
Log.e("软键盘弹出了", "软键盘弹出");
confim.setVisibility(View.GONE);
} else if (heightDiff < 100) {
Log.e("软键盘弹出了", "软键盘没有弹出");
confim.setVisibility(View.VISIBLE);
//new Thread(Confim).start();
}
}
});
}
10.ListView被键盘遮挡的问题处理:
用ListView或者其它显示大量Items的控件实时跟踪或者查看信息,并且希望最新的条目可以自动滚动到可视范围内。通过设置控件transcriptMode属性可以将Android平台的控件(支持ScrollBar)自动滑动到最底部。
1).方法一:
android:transcriptMode="alwaysScroll"
2).方法二: