最近研究android的material design中的TextInputLayout发现setError()隐藏之后就无法再显示。
通过源码发现此问题出现在compile 'com.android.support:design:24.0.0'之下， 24.0.0版本已修复此问题
此问题具体情况：
<android.support.design.widget.TextInputLayout
android:id="@+id/password"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password" />
</android.support.design.widget.TextInputLayout>
final TextInputLayout user = (TextInputLayout )findViewById(R.id.password);
EditText editText = user.getEditText();
editText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start,
int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.length() > 4){
user.setError("Password Error");
}else{
//user.setError("");
user.setErrorEnabled(false);
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
通过上面的代码，则当输入框中的字符长度超过4个时则会在输入框底下显示Password Error提示。但是当删除输入框中输入少于4字符时提示消除，当输入字符再次超过4时就不会显示提示。需要把上面代码改为：
if(s.length() > 4){
user.setError("Password Error");
}else{
user.setError("");
user.setErrorEnabled(false);
}
通过源码发现：
public void setError(@Nullable final CharSequence error) {
if (TextUtils.equals(mError, error)) {
// If we already have the same error, ignore
return;
}
mError = error;
if (!mErrorEnabled) {
if (TextUtils.isEmpty(error)) {
// If error isn't enabled, and the error is empty, just return
return;
}
// Else, we'll assume that they want to enable the error functionality
setErrorEnabled(true);
}
// Only animate if we've been laid out already
final boolean animate = ViewCompat.isLaidOut(this);
mErrorShown = !TextUtils.isEmpty(error);
if (mErrorShown) {
mErrorView.setText(error);
mErrorView.setVisibility(VISIBLE);
if (animate) {
if (ViewCompat.getAlpha(mErrorView) == 1f) {
// If it's currently 100% show, we'll animate it from 0
ViewCompat.setAlpha(mErrorView, 0f);
}
ViewCompat.animate(mErrorView)
.alpha(1f)
.setDuration(ANIMATION_DURATION)
.setInterpolator(AnimationUtils.LINEAR_OUT_SLOW_IN_INTERPOLATOR)
.setListener(new ViewPropertyAnimatorListenerAdapter() {
@Override
public void onAnimationStart(View view) {
view.setVisibility(VISIBLE);
}
}).start();
}
} else {
if (mErrorView.getVisibility() == VISIBLE) {
if (animate) {
ViewCompat.animate(mErrorView)
.alpha(0f)
.setDuration(ANIMATION_DURATION)
.setInterpolator(AnimationUtils.FAST_OUT_LINEAR_IN_INTERPOLATOR)
.setListener(new
ViewPropertyAnimatorListenerAdapter() {
@Override
public void onAnimationEnd(View view) {
mErrorView.setText(error);
view.setVisibility(INVISIBLE);
}
}).start();
} else {
mErrorView.setVisibility(INVISIBLE);
}
}
}
updateEditTextBackground();
updateLabelState(true);}
函数的首部：
if (TextUtils.equals(mError, error)) {
// If we already have the same error, ignore
return;
}
先判断当前需显示的error是否与上次的相等， 如果相等则不会再显示了。所以我们需要在不显示的时候把mError值为“ ”
compile 'com.android.support:design:24.0.0'版本中的已删除了下面的代码段：
if (TextUtils.equals(mError, error)) {
// If we already have the same error, ignore
return;
}
