Android EditText 的实时字符数
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原文地址: http://stackoverflow.com/questions/3013791/
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Live character count for EditText
提问by Taylor Perkins
I was wondering what the best way to do a live character count of an edit-text box is in Android. I was looking at thisbut I couldn't seem to make any sense of it.
我想知道在 Android 中对编辑文本框进行实时字符计数的最佳方法是什么。我正在看这个，但我似乎无法理解它。
To describe the problem, I have an EditText and I'm trying to limit the characters to 150. I can do this with an input filter, however I want to show right below the text box the number of characters a user has entered(Almost like stack overflow is doing right now).
为了描述这个问题，我有一个 EditText，我试图将字符限制为 150。我可以使用输入过滤器来做到这一点，但是我想在文本框下方显示用户输入的字符数（几乎就像堆栈溢出现在正在做的一样）。
If someone could write a small snippet of example code or point me in the right direction I'd appreciate it a lot.
如果有人可以编写一小段示例代码或为我指明正确的方向，我将不胜感激。
回答by Cameron Ketcham
you can use a TextWatcher to see when the text has changed
您可以使用 TextWatcher 查看文本何时更改
private TextView mTextView;
private EditText mEditText;
private final TextWatcher mTextEditorWatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
//This sets a textview to the current length
mTextView.setText(String.valueOf(s.length()));
}
public void afterTextChanged(Editable s) {
}
};
you set the TextWatcher for the edittext with
你为edittext设置TextWatcher
mEditText.addTextChangedListener(mTextEditorWatcher);
回答by Midhun Vijayakumar
You can do character counting from xml itself using TextInputLayoutwrapper for EditText introduced in SupportLibrary v23.1
您可以使用SupportLibrary v23.1 中引入的 EditText 的TextInputLayout包装器从 xml 本身进行字符计数
Just wrap your EditText with a TextInputLayout and set CounterEnabled to true and Set a counterMaxLength.
只需用 TextInputLayout 包装您的 EditText 并将 CounterEnabled 设置为 true 并设置一个 counterMaxLength。
<android.support.design.widget.TextInputLayout
android:id="@+id/textContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:counterEnabled="true"
app:counterMaxLength="20"
>
<EditText
android:id="@+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Text Hint"
/>
</android.support.design.widget.TextInputLayout>
You'll get a material effect like this
你会得到这样一个重大的影响这
You may use counterOverflowTextAppearance, counterTextAppearanceto style the counter.
您可以使用counterOverflowTextAppearance、counterTextAppearance来设置计数器的样式。
EDIT
编辑
From Android documentation.
来自 Android 文档。
The TextInputEditTextclass is provided to be used as a child of this layout. Using TextInputEditText allows TextInputLayout greater control over the visual aspects of any text input. An example usage is as so:
该TextInputEditText提供一流用作此布局的孩子。使用 TextInputEditText 允许 TextInputLayout 更好地控制任何文本输入的视觉方面。示例用法如下：
<android.support.design.widget.TextInputLayout
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="@string/form_username"/>
</android.support.design.widget.TextInputLayout>
回答by Daniel Gomez Rico
You can do it with TextInputLayoutand compat libraries with:
您可以使用TextInputLayout和兼容库来做到这一点：
app:counterEnabled="true"
app:counterMaxLength="420"
and complete:
并完成：
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:counterEnabled="true"
app:counterMaxLength="420">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLength="420" />
</android.support.design.widget.TextInputLayout>
回答by Amal Kronz
in xml add this attribute for editText
在 xml 中为 editText 添加此属性
android:maxLength="80"
in java add this listener
在java中添加这个监听器
ed_caption.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) {
}
@Override
public void afterTextChanged(Editable s) {
tv_counter.setText(80 - s.toString().length() + "/80");
}
});
回答by Depinder Bharti
Its very Simple Follow the instructions below:
它非常简单 请按照以下说明操作：
====Add them to your Imports===
====将它们添加到您的导入中===
import android.text.Editable;
import android.text.TextWatcher;
=====Define this=====
======定义这个=====
private TextView sms_count;
==========Inside On Create=====
==========内部创建====
sms_count = (TextView) findViewById(R.id.textView2);
final TextWatcher txwatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
sms_count.setText(String.valueOf(s.length()));
}
public void afterTextChanged(Editable s) {
}
};
sms_message.addTextChangedListener(txwatcher);
回答by Rana Pratap Singh
You can use TextWatcher class to see text has changed and how much number of character remains.Here i have set counter of 140 characters.
EditText typeMessageToPost;
TextView number_of_character;
public void onCreate(Bundle savedBundleInstance) {
super.onCreate(savedBundleInstance);
setContentView(R.layout.post_activity);
typeMessageToPost.addTextChangedListener(mTextEditorWatcher);
}
private final TextWatcher mTextEditorWatcher=new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// TODO Auto-generated method stub
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
number_of_character.setText(String.valueOf(140-s.length()));
}
};
回答by mortezahosseini
Just set these 2 lines in TextInputLayoutin your XML file:
只需TextInputLayout在您的 XML 文件中设置这两行：
app:counterEnabled="true"
app:counterMaxLength="200"
回答by Sathish
You can add a counter to your TextInputEditText being wrapped in a TextInputLayout. As you can see in the example, counterEnabledenables this feature and counterMaxLenghdefines the number of characters for it.
您可以向包装在 TextInputLayout 中的 TextInputEditText 添加一个计数器。正如您在示例中看到的，counterEnabled启用此功能并counterMaxLengh为其定义字符数。
<com.google.android.material.textfield.TextInputLayout
android:id="@+id/til_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:counterEnabled="true"
app:counterMaxLength="50">
<com.google.android.material.textfield.TextInputEditText
android:id="@+id/et_title"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</com.google.android.material.textfield.TextInputLayout>
回答by grantespo
This solution uses Kotlinand shows the number of characters left. Also, if the current number of characters surpasses the limit of 50, the text color will change to red.
此解决方案使用Kotlin并显示剩余的字符数。此外，如果当前字符数超过 50 的限制，文本颜色将变为红色。
Kotlin
科特林
private val mTitleTextWatcher = object : TextWatcher {
override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
if(YOUR_EDIT_TEXT_ID.text.toString().trim().length < 51){
YOUR_CHAR_LEFT_TEXTVIEW_ID.text = (50 - YOUR_EDIT_TEXT_ID.text.toString().trim().length).toString()
YOUR_CHAR_LEFT_TEXTVIEW_ID.setTextColor(Color.BLACK)
}
else{
YOUR_CHAR_LEFT_TEXTVIEW_ID.text = "0"
YOUR_CHAR_LEFT_TEXTVIEW_ID.setTextColor(Color.RED)
}
}
override fun afterTextChanged(s: Editable) {}
}
Also, don't forget to add the TextWatcherto your EditText
另外，不要忘记添加TextWatcher到您的EditText
YOUR_EDIT_TEXT_ID.addTextChangedListener(mTitleTextWatcher)
回答by Alireza Ghanbarinia
Use android:maxLength="140"
使用 android:maxLength="140"
That should work. :)
那应该工作。:)
Hope that helps
希望有帮助
