“我们已经有一个EditText，只能有一个”
我为我的应用程序（LoginFragment）构建了一个Fragment，它可以处理两种主要的身份验证模式;即登录和注册用户。有一个按钮允许用户在“登录模式”和“注册”模式之间切换。每个“模式”都有一些额外的视图，而另一个视图则不需要。因此，在切换模式时需要添加和删除视图。
我在TextInputLayout布局中使用EditText视图。当我执行以下操作时，我的应用程序崩溃了：
这是我得到的错误：
java.lang.IllegalArgumentException: We already have an EditText, can only have one
at android.support.design.widget.TextInputLayout.setEditText(TextInputLayout.java:166)
at android.support.design.widget.TextInputLayout.addView(TextInputLayout.java:155)
at android.view.ViewGroup.addView(ViewGroup.java:3985)
at android.view.ViewGroup.addView(ViewGroup.java:3961)
at com.mydomain.myapp.fragments.LoginFragment.showActivateAccountViews(LoginFragment.java:317)
这来自android.support.design.widget.TextInputLayout，它有一个内部私有EditText变量，在添加视图时设置（源代码如下）。当我尝试第二次将视图添加到TextInputLayout时，mEditText变量已经设置了。该类没有自己的.removeView（）方法，所以我不知道应该如何删除它？
我怀疑我正在错误地删除EditText视图，但无法弄清楚我做错了什么。我还阅读了其他一些处理删除视图的Stack Overflow帖子，但这些方法也没有解决问题。
有没有人对如何让它发挥作用有任何想法？
以下是我自己的代码供参考。
LoginFragment.java
...
import android.support.design.widget.TextInputLayout;
import android.widget.EditText;
public class LoginFragment extends Fragment {
private RelativeLayout mContainer;
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_login, container, false);
mContainer = ((RelativeLayout) view.findViewById(R.id.login_container));
showLoginViews();
LayoutTransition layoutTransition = mContainer.getLayoutTransition();
layoutTransition.enableTransitionType(LayoutTransition.CHANGING);
return view;
}
/**
* Show the view elements for Login mode
*/
private void showLoginViews() {
LayoutInflater li = (LayoutInflater)getActivity().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
// Configure the button for the primary action
Button loginButton = (Button)mContainer.findViewById(R.id.button_login_fragment_primary_action);
...
// Configure the toggle button to navigate to Activate Account mode
TextView toggleButton = (TextView)mContainer.findViewById(R.id.button_toggle_mode);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LoginFragment.this.showActivateAccountViews();
}
});
toggleButton.setText(getResources().getString(R.string.action_activate_account));
// Hide the Member ID EditText
((TextInputLayout)mContainer.findViewById(R.id.member_id_inputlayout)).removeView(mContainer.findViewById(R.id.editText_member_id_field));
}
/**
* Show view elements for Activate Account mode
*/
private void showActivateAccountViews() {
LayoutInflater li = (LayoutInflater)getActivity().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
// Configure the primary button for the primary action - Activate Account
Button activateAccountButton = (Button)mContainer.findViewById(R.id.button_login_fragment_primary_action);
...
// Add the Member ID EditText
((TextInputLayout)mContainer.findViewById(R.id.member_id_inputlayout)).addView(li.inflate(R.layout.login_member_id_element_layout, (ViewGroup)mContainer.findViewById(R.id.member_id_inputlayout), false));
// Configure the toggle button to navigate to Login mode
TextView toggleButton = (TextView)mContainer.findViewById(R.id.button_toggle_mode);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LoginFragment.this.showLoginViews();
}
});
toggleButton.setText(getResources().getString(R.string.action_login));
}
...
}
login_member_id_element_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<EditText xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/editText_member_id_field"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/member_id" />
login_fragment.xml
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context="com.mydomain.myapp.fragments.LoginFragment">
<RelativeLayout
android:id="@+id/login_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true">
<!--placeholder layout with params for activate account elements-->
<android.support.design.widget.TextInputLayout
android:id="@+id/member_id_inputlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!-- a view can be added here-->
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/email_inputlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/editText_email_field"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:inputType="textEmailAddress" />
</android.support.design.widget.TextInputLayout>
<Button
android:id="@+id/button_login_fragment_primary_action"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/password_inputlayout"
android:text="@string/action_login" />
<!-- Toggle button for Login/Activate Account-->
<TextView
android:id="@+id/button_toggle_mode"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/action_activate_account" />
</RelativeLayout>
</android.support.design.widget.CoordinatorLayout>
android.support.design.widget.TextInputLayout （来自最新的22.2.1支持库）
public class TextInputLayout extends LinearLayout {
private EditText mEditText;
...
public void addView(View child, int index, LayoutParams params) {
if(child instanceof EditText) {
android.widget.LinearLayout.LayoutParams params1 = this.setEditText((EditText)child, params);
super.addView(child, 0, params1);
} else {
super.addView(child, index, params);
}
}
private android.widget.LinearLayout.LayoutParams setEditText(EditText editText, LayoutParams lp) {
if(this.mEditText != null) {
throw new IllegalArgumentException("We already have an EditText, can only have one");
} else {
this.mEditText = editText;
this.mCollapsingTextHelper.setExpandedTextSize(this.mEditText.getTextSize());
this.mEditText.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
TextInputLayout.this.mHandler.sendEmptyMessage(0);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
});
this.mDefaultTextColor = this.mEditText.getHintTextColors().getDefaultColor();
this.mEditText.setOnFocusChangeListener(new OnFocusChangeListener() {
public void onFocusChange(View view, boolean focused) {
TextInputLayout.this.mHandler.sendEmptyMessage(0);
}
});
if(TextUtils.isEmpty(this.mHint)) {
this.setHint(this.mEditText.getHint());
this.mEditText.setHint((CharSequence)null);
}
if(this.mErrorView != null) {
ViewCompat.setPaddingRelative(this.mErrorView, ViewCompat.getPaddingStart(this.mEditText), 0, ViewCompat.getPaddingEnd(this.mEditText), this.mEditText.getPaddingBottom());
}
this.updateLabelVisibility(false);
android.widget.LinearLayout.LayoutParams newLp = new android.widget.LinearLayout.LayoutParams(lp);
Paint paint = new Paint();
paint.setTextSize(this.mCollapsingTextHelper.getExpandedTextSize());
newLp.topMargin = (int)(-paint.ascent());
return newLp;
}
}
}
答案 0 :(得分：3)
com.android.support.design库（v22.2.1）似乎存在限制。您无法在运行时直接删除然后将EditText添加到TextInputLayout。你可以将此错误标记为here。
我已经为这个问题设计了一个解决方法。我修改了xml布局，以便不在运行时从TextInputLayout添加/删除EditText视图（这不起作用），我们将TextInputLayout本身添加/删除到LinearLayout持有者。使用此解决方案，我们永远不需要从TextInputLayout中实际删除EditText。
关于此解决方案唯一需要注意的是，它使您的视图层次结构比其他方式更深入。因此，如果您已经遇到UI性能问题，请记住这一点。如果您正在阅读此版本并且com.android.support.design v22.2.1版本可用，则可能需要检查此问题是否已解决。
否则请参阅下面的示例代码以了解我的变通方法的实现。
<强> LoginFragment.java
import android.support.design.widget.TextInputLayout;
import android.widget.EditText;
public class LoginFragment extends Fragment {
private RelativeLayout mContainer;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_login, container, false);
mContainer = ((RelativeLayout) view.findViewById(R.id.login_container));
showLoginViews();
LayoutTransition layoutTransition = mContainer.getLayoutTransition();
layoutTransition.enableTransitionType(LayoutTransition.CHANGING);
return view;
}
/**
* Show the view elements for Login mode
*/
private void showLoginViews() {
LayoutInflater li = (LayoutInflater)getActivity().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
// Configure the toggle button to navigate to Activate Account mode
s TextView toggleButton = (TextView)mContainer.findViewById(R.id.button_toggle_mode);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LoginFragment.this.showActivateAccountViews();
}
});
toggleButton.setText(getResources().getString(R.string.action_activate_account));
// Hide the Member ID EditText
((LinearLayout)mContainer.findViewById(R.id.member_id_holderlayout)).removeView(mContainer.findViewById(R.id.member_id_inputlayout));
}
/**
* Show view elements for Activate Account mode
*/
private void showActivateAccountViews() {
LayoutInflater li = (LayoutInflater)getActivity().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
// Configure the primary button for the primary action - Activate Account
Button activateAccountButton = (Button)mContainer.findViewById(R.id.button_login_fragment_primary_action);
// Add the Member ID EditText
((LinearLayout)mContainer.findViewById(R.id.member_id_holderlayout)).addView(li.inflate(R.layout.login_member_id_element_layout, (ViewGroup) mContainer.findViewById(R.id.member_id_inputlayout), false));
// Configure the toggle button to navigate to Login mode
TextView toggleButton = (TextView)mContainer.findViewById(R.id.button_toggle_mode);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LoginFragment.this.showLoginViews();
}
});
toggleButton.setText(getResources().getString(R.string.action_login));
}
}
<强> login_member_id_element_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.TextInputLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/member_id_inputlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/editText_member_id_field"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/member_id" />
</android.support.design.widget.TextInputLayout>
<强> login_fragment.xml
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<RelativeLayout
android:id="@+id/login_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--placeholder for TextInputLayout to be dynamically added at runtime-->
<LinearLayout
android:id="@+id/member_id_holderlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<!-- a login_member_id_element_layout can be dynamically added/removed here at runtime-->
</LinearLayout>
<!--TextInputLayout for static fields, the EditText is not removed at runtime-->
<android.support.design.widget.TextInputLayout
android:id="@+id/email_inputlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/member_id_holderlayout">
<EditText
android:id="@+id/editText_email_field"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:drawablePadding="@dimen/edittext_drawable_padding"
android:drawableStart="?emailIcon"
android:focusable="true"
android:hint="Email"
android:inputType="textEmailAddress" />
</android.support.design.widget.TextInputLayout>
</RelativeLayout>
</android.support.design.widget.CoordinatorLayout>
答案 1 :(得分：0)
恭喜，您（可能？）发现了一个可能的错误（或者我应该说删除TextInputLayout的{{1}}时会出现非预期行为？）
您可以看到EditText是ViewGroup的方法。它会从{View> 子视图的数组中删除removeView()，但不会删除View对InputTextLayout的引用。
那我该怎么办？
您必须扩展EditText并创建自己的方法，将TextInputLayout设置为super.mEditText。问题是你仍然需要调用这两种方法，因为只需将null引用设置为null，就可以在应用程序生命周期中将旧布局留在内存中。