nougat.png

备注

这个需求是大家经常用到的，比如在控制用户名输入时经常要用到。

此方法是设置文本监听器，省事，好用，且ROM，平台无关。

code

    private static final String SPECIAL_CHARACTERS =  "[\"\"''`~!@#$%^&*()+=|{}':;',\\[\\].<>/?~！
    @#￥%……&*（）—-—+|{}【】‘；：”“’。，、？]";
    private static final Pattern NAME_PATTERN;
    static {
        NAME_PATTERN = Pattern.compile(SPECIAL_CHARACTERS);
    }
 
 
    private TextWatcher textWatcher = new TextWatcher() {
        private int editStart;
        private int editEnd;
        private int maxLen = 20;
        @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) {
            editStart = mEditText.getSelectionStart();
            editEnd = mEditText.getSelectionEnd();
            mEditText.removeTextChangedListener(textWatcher);
            if (!TextUtils.isEmpty(mEditText.getText())) {
                String etstring = mEditText.getText().toString().trim();
                while (calculateLength(s.toString()) > maxLen) {
                    s.delete(editStart - 1, editEnd);
                    editStart--;
                    editEnd--;
                }
            }
            mEditText.setText(s);
            mEditText.setSelection(editStart);
            Matcher m = NAME_PATTERN.matcher(s);
            if( m.find()){
                ToastUtils.showToast(mContext, R.string.robot_name_error);
                editStart = mEditText.getSelectionStart();
                s.delete( mEditText.getSelectionEnd() - 1, mEditText.getSelectionEnd());
                mEditText.setText(s);
                mEditText.setSelection(editStart - 1);
            }
            mEditText.addTextChangedListener(textWatcher);
        }

        private int calculateLength(String etstring) {
            char[] ch = etstring.toCharArray();
            int varlength = 0;
            for (int i = 0; i < ch.length; i++) {
                if ((ch[i] >= 0x2E80 && ch[i] <= 0xFE4F) || (ch[i] >= 0xA13F 
                && ch[i] <= 0xAA40) || ch[i] >= 0x80) {
                    varlength = varlength + 2;
                } else {
                    varlength++;
                }
            }
            return varlength;
        }
    };

使用时，只需要

mEditText.addTextChangedListener(textWatcher);

或者使用自定义的EditText类，我写的，目前而言，扩展性实用性还不错，还是可以一用的

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import android.content.Context;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.widget.EditText;
import android.widget.Toast;

/**
 * you can use it like:
 *     mEditText.setToastString(getResources().getString(R.string.robot_name_error))
 *              .setWordCountLimit(5)
 *              .setFormatPattern(SPECIAL_CHARACTERS);
 *
 *     if you want a toast , you must call setToastString(ToastString)
 *     if you want a custom FormatPattern, you should call setFormatPattern(String str)
 *     if you want add your TextWatcher, call removeDefaultTextWatcher() first
 *     if you want get string igno space, call getString()
 */
public class EditTextFormated extends EditText {

    private String mToastString;
    private int mMaxLen = 20;
    private static final String DEFAULT_SPECIAL_CHARACTERS =
            "[\"\"''`~!@#$%^&*()+=|{}':;',\\[\\].<>/?~！@#￥%……&*"
            + "（）---—-—+|{}【】‘；：”“’。，、？]";
    private Pattern mPattern;

    public EditTextFormated(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initFormat();
    }

    public EditTextFormated(Context context, AttributeSet attrs) {
        super(context, attrs);
        initFormat();
    }

    public EditTextFormated(Context context) {
        super(context);
        initFormat();
    }

    private void initFormat() {
        mPattern = Pattern.compile(DEFAULT_SPECIAL_CHARACTERS);
        addTextChangedListener(mDefaultTextWatcher);
    }

    private TextWatcher mDefaultTextWatcher = new TextWatcher() {
        private int editStart;
        private int editEnd;
        private String mBeforeString;

        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
        }

        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            mBeforeString = s.toString();
        }

        public void afterTextChanged(Editable s) {
            editStart = getSelectionStart();
            editEnd = getSelectionEnd();
            removeTextChangedListener(this);
            if (!TextUtils.isEmpty(getString())) {
                while (calculateLength(s.toString()) > mMaxLen) {
                    s.delete(editStart - 1, editEnd);
                    editStart--;
                    editEnd--;
                }
            }
            Matcher matcher = mPattern.matcher(s);
            if (matcher.find()) {
                if (mToastString != null) {
                    Toast.makeText(getContext(), mToastString,
                            Toast.LENGTH_SHORT).show();
                }
                setText(mBeforeString);
                setSelection(mBeforeString.length());
                addTextChangedListener(this);
                return;
            }
            setText(s);
            setSelection(editStart);
            addTextChangedListener(this);
        }

        private int calculateLength(String etstring) {
            char[] ch = etstring.toCharArray();
            int varlength = 0;
            for (int i = 0; i < ch.length; i++) {
                if ((ch[i] >= 0x2E80 && ch[i] <= 0xFE4F)
                        || (ch[i] >= 0xA13F && ch[i] <= 0xAA40)
                        || ch[i] >= 0x80) {
                    varlength = varlength + 2;
                } else {
                    varlength++;
                }
            }
            return varlength;
        }
    };

    /**
     * for Personalise TextWatcher you should call this method first
     */
    public EditTextFormated removeDefaultTextWatcher() {
        removeTextChangedListener(mDefaultTextWatcher);
        return this;
    }

    /**
     * get text and ignore spaces
     * @return String
     */
    public String getString() {
        return getText().toString().trim();
    }

    /**
     * set the Special characters Toast string
     * @param hint
     */
    public EditTextFormated setToastString(String hint) {
        mToastString = hint;
        return this;
    }

    public EditTextFormated setWordCountLimit(int len) {
        mMaxLen = len;
        return this;
    }

    public EditTextFormated setFormatPattern(String str) {
        mPattern = Pattern.compile(str);
        return this;
    }
}

谢谢大家阅读，如有帮助，来个喜欢或者关注吧！

本文作者：Anderson/Jerey_Jobs

简书地址：[Anderson大码渣][1]

github地址：[Jerey_Jobs][2]
[1]: http://www.jianshu.com/users/016a5ba708a0/latest_articles
[2]: https://github.com/Jerey-Jobs