Android Material Design：TextInputLayout详解

TextInputLayout是什么

TextInputLayout主要是作为EditText的容器，从而为EditText生成一个浮动的Label，当用户点击EditText的时候，EditText中的hint字符串会自动移到EditText的左上角。

TextInputLayout如何使用

●基本用法

xml布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_marginTop="20dp"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:hint="请输入用户名"
            android:layout_height="wrap_content" />
    </android.support.design.widget.TextInputLayout>
    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_marginTop="20dp"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:hint="请输入邮箱"
            android:layout_height="wrap_content" />
    </android.support.design.widget.TextInputLayout>
</LinearLayout>

●设置最大字符数及错误提示

xml

<android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_marginTop="20dp"
        app:counterEnabled="true" //设置为true才能显字符数
        app:counterMaxLength="5" //设置最大字符数为5
        app:counterOverflowTextAppearance="@style/HintError" //设置超出字符数后提示文字的颜色，如果不设置默认为@color/colorAccent的颜色
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:hint="请输入用户名"
            android:layout_height="wrap_content" />
</android.support.design.widget.TextInputLayout>

style文件（设置超出字符数的文字提示颜色为红色）

<style name="HintError" parent="TextAppearance.AppCompat">
        <item name="android:textColor">@color/colorRed</item>
</style>

●设置错误提示文字

xml

<android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_marginTop="20dp"
        app:errorEnabled="true" //设置为true
        android:id="@+id/textinputlayout_email"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:hint="请输入邮箱"
            android:id="@+id/et_email"
            android:layout_height="wrap_content" />
</android.support.design.widget.TextInputLayout>

java代码

editText_email=findViewById(R.id.et_email);
        textInputLayout =findViewById(R.id.textinputlayout_email);
        editText_email.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                if(!RegexUtils.isEmail(charSequence)){
                    textInputLayout.setError("邮箱格式错误");
                    textInputLayout.setErrorEnabled(true);
                }else {
                    textInputLayout.setErrorEnabled(false);
                }
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

●设置密码是否可见

xml

<android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_marginTop="20dp"
        app:errorEnabled="true"
        app:passwordToggleEnabled="true" //设置为true
        android:id="@+id/textinputlayout_password"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:hint="请输入密码"
            android:id="@+id/et_password"
            android:inputType="textPassword"
            android:layout_height="wrap_content" />
    </android.support.design.widget.TextInputLayout>