import android.text.Editable;import android.text.InputFilter;import android.text.TextWatcher;import android.widget.EditText;/** * EditText 限制輸入整數和小數 的位數 * 默認 整數位無限制，小數位 最多2位 */public class DecimalInputTextWatcher implements TextWatcher {  private static final int DEFAULT_DECIMAL_DIGITS = 2;//默認 小數的位數  2 位  private EditText editText;  private int decimalDigits;// 小數的位數  private int integerDigits;// 整數的位數  public DecimalInputTextWatcher(EditText editText) {    this.editText = editText;    this.decimalDigits = DEFAULT_DECIMAL_DIGITS;  }  public DecimalInputTextWatcher(EditText editText, int decimalDigits) {    this.editText = editText;    if (decimalDigits <= 0)      throw new RuntimeException("decimalDigits must > 0");    this.decimalDigits = decimalDigits;  }  public DecimalInputTextWatcher(EditText editText, int integerDigits, int decimalDigits) {    this.editText = editText;    if (integerDigits <= 0)      throw new RuntimeException("integerDigits must > 0");    if (decimalDigits <= 0)      throw new RuntimeException("decimalDigits must > 0");    this.decimalDigits = decimalDigits;    this.integerDigits = integerDigits;  }  @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 editable) {    String s = editable.toString();    editText.removeTextChangedListener(this);    if (s.contains(".")) {      if (integerDigits > 0) {        editText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(integerDigits + decimalDigits + 1)});      }      if (s.length() - 1 - s.indexOf(".") > decimalDigits) {        s = s.substring(0,            s.indexOf(".") + decimalDigits + 1);        editable.replace(0, editable.length(), s.trim());//不輸入超出位數的數字      }    } else {      if (integerDigits > 0) {        editText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(integerDigits + 1)});        if (s.length() > integerDigits) {          s = s.substring(0, integerDigits);          editable.replace(0, editable.length(), s.trim());        }      }    }    if (s.trim().equals(".")) {//小數點開頭，小數點前補0      s = "0" + s;      editable.replace(0, editable.length(), s.trim());    }    if (s.startsWith("0") && s.trim().length() > 1) {//多個0開頭，只輸入一個0      if (!s.substring(1, 2).equals(".")) {        editable.replace(0, editable.length(), "0");      }    }    editText.addTextChangedListener(this);  }}

editText.addTextChangedListener(new DecimalInputTextWatcher(weight, 3, 5));//限制輸入位數：整數3位，小數點后兩位