Android EditText Space Validation

问题:

I have an Edittext in my android application. I don't want to allow user to enter first space character..but after entering other charecter user can enter space also..I used

    <EditText
    android:id="@+id/editText1_in_row"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="text" 
    android:digits="_,qwertzuiopasdfghjklyxcvbnm,QWERTYUIOPASDFGHJKLZXCVBNM,0123456789">

but in this case user can not enter space.

I have also used Text Watcher but I need not to allow user at the time of entering text as android:digits works.

回答1:

final EditText editText = (EditText)findViewById(R.id.editText1_in_row);


        InputFilter filter = new InputFilter() { 
            boolean canEnterSpace = false;

            public CharSequence filter(CharSequence source, int start, int end,
                    Spanned dest, int dstart, int dend) {

                if(editText.getText().toString().equals(""))
                {
                    canEnterSpace = false;
                }

                StringBuilder builder = new StringBuilder();

                for (int i = start; i < end; i++) { 
                    char currentChar = source.charAt(i);

                    if (Character.isLetterOrDigit(currentChar) || currentChar == '_') {
                        builder.append(currentChar);
                        canEnterSpace = true;
                    }

                    if(Character.isWhitespace(currentChar) && canEnterSpace) {
                        builder.append(currentChar);
                    }


                }
                return builder.toString();          
            }

        };


        editText.setFilters(new InputFilter[]{filter});

and remove this property from your EditText

android:digits="_,qwertzuiopasdfghjklyxcvbnm,QWERTYUIOPASDFGHJKLZXCVBNM,0123456789"

This code works exactly according to your needs.

回答2:

Using InputFilter easy to handle enter first white space character ignore

First setFilters() method on editText

editText.setFilters(new InputFilter[]{ignoreFirstWhiteSpace()});

Make InputFilter

    // ignore enter First space on edittext
    public InputFilter ignoreFirstWhiteSpace() {
        return new InputFilter() {
            public CharSequence filter(CharSequence source, int start, int end,
                                       Spanned dest, int dstart, int dend) {

                for (int i = start; i < end; i++) {
                    if (Character.isWhitespace(source.charAt(i))) {
                        if (dstart == 0)
                            return "";
                    }
                }
                return null;
            }
        };
    }

No need to write android:digits property on XML

remove this line

android:digits="_,qwertzuiopasdfghjklyxcvbnm,QWERTYUIOPASDFGHJKLZXCVBNM,0123456789"

回答3:

why cant you use editText.getText().trim(); function while using the EditText data

回答4:

If you want to filter input characters in your EditText, you need to use InputFilter. Here is example. //Allow only letters or digits

InputFilter filter = new InputFilter() { 
   public CharSequence filter(CharSequence source, int start, int end,
     Spanned dest, int dstart, int dend) {
    for (int i = start; i < end; i++) { 
              if (!Character.isLetterOrDigit(source.charAt(i))) { 
                  return ""; 
              }
          }
    return null;
   } 
        }; 

 EditText text = (EditText)findViewById(R.id.edittext1);
text.setFilters(new InputFilter[]{filter});

For details look here

回答5:

Use this. If the character at starting Position is a space, set textView Text To blank

editText1_in_row.addTextChangedListener(new TextWatcher() {

                @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                    if (s.length()>0 && s.subSequence(0, 1).toString().equalsIgnoreCase(" ")) {
                        editText1_in_row.setText("");               }

                }

                @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

                }
            });

回答6:

A slight variation on https://stackoverflow.com/users/2868352/abhishek-v answer.

public class NoInitialSpaceFilter implements InputFilter {
    @Override
    public CharSequence filter(final CharSequence source, final int start, final int end, final Spanned dest, final int dstart, final int dend) {
        if (dstart == 0) {
            for (int i = start; i < end; i++) {
                if (Character.isSpaceChar(source.charAt(i))) {
                    return "";
                }
            }
        }
        return null;
    }
}

Usage:

editText.setFilters(new InputFilter[]{new NoInitialSpaceFilter});

回答7:

Simply restrict the user to type space as others said on start only:

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            String text = createPL.getText().toString();

            //restrict space for first char
            if (text.startsWith(" ")) {
                edittext.setText(text.trim());
            }

        }

回答8:

This works for me

 android:inputType="textPersonName"
 android:digits= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890_-!@#$%^*()"

回答9:

android:digits="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890.,_-!@#$()+=><:;?"