常见问题及解决方案
限制为单行
android:inputType="text"
更改背景为底部一条线
drawable/edittext_background.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="true" android:drawable="@drawable/edittext_focused" />
<item android:drawable="@drawable/edittext_normal" />
</selector>
drawable/edittext_normal.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:left="-1dp"
android:right="-1dp"
android:top="-1dp">
<shape>
<solid android:color="#00FFFFFF" />
<stroke
android:width="1dp"
android:color="#FFFFFF" />
</shape>
</item>
</layer-list>
drawable/edittext_focused.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:left="-1dp"
android:right="-1dp"
android:top="-1dp">
<shape>
<solid android:color="#00FFFFFF" />
<stroke
android:width="1dp"
android:color="@android:color/holo_green_dark" />
</shape>
</item>
</layer-list>
更换光标颜色
layout/xxx.xml
<EditText
...
android:textCursorDrawable="@drawable/edittext_cursor"
/>
drawable/edittext_cursor.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<size android:width="1dp" />
<solid android:color="@android:color/holo_green_dark" />
</shape>
解决获取到焦点后光标自动跳到最前面的问题
editText.setText(content);
editText.setSelection(content.length());
限制只能输入数字，最大长度为 9 位
<EditText
...
android:inputType="number"
android:digits="0123456789"
android:maxLength="9"
...
/>
限制只能输入 IP 地址
EditText ipEditText = (EditText) root.findViewById(R.id.ip_address);
InputFilter[] filters = new InputFilter[1];
filters[0] = new InputFilter() {
@Override
public CharSequence filter(CharSequence source, int start,
int end, Spanned dest, int dstart, int dend) {
if (end > start) {
String destTxt = dest.toString();
String resultingTxt = destTxt.substring(0, dstart) +
source.subSequence(start, end) +
destTxt.substring(dend);
if (!resultingTxt.matches ("^\\d{1,3}(\\." +
"(\\d{1,3}(\\.(\\d{1,3}(\\.(\\d{1,3})?)?)?)?)?)?")) {
return "";
} else {
String[] splits = resultingTxt.split("\\.");
for (int i=0; i<splits.length; i++) {
if (Integer.valueOf(splits[i]) > 255) {
return "";
}
}
}
}
return null;
}
};
ipEditText.setFilters(filters);
顺便给一个校验 IP 地址是否有效的工具方法：
public static boolean isIpAddress(String text) {
Pattern p = Pattern.compile("^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$");
Matcher m = p.matcher(text);
return m.find();
}
显示隐藏密码
if (show) {
// 显示
mPasswordEditText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
} else {
// 隐藏
mPasswordEditText.setTransformationMethod(PasswordTransformationMethod.getInstance());
}
setInputType 的方法在我尝试的过程中有点问题，表现与预期不一致。
imeOptions
举个例子，让软件键盘的回车键变成“搜索”，并且点击的时候执行某特定动作：
<EditText
...
android:imeOptions="actionSearch"
android:inputType="text" />
editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
if ((event != null) && event.getKeyCode() == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_DOWN) {
onSearch();
return true;
} else if (actionId == EditorInfo.IME_ACTION_SEARCH) {
onSearch();
return true;
}
return false;
}
});
imeOptions 还可以对应一些其它的值，详见 https://developer.android.com/reference/android/widget/TextView.html#attr_android:imeOptions