public classMainActivityextendsAppCompatActivity {

privateTextViewmTextView;

privateEditTextmEditText;

@Override

public voidonCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mTextView= (TextView)findViewById(R.id.tv);

mEditText= (EditText)findViewById(R.id.ET);

mEditText.addTextChangedListener(mTextWatcher);

}

TextWatchermTextWatcher=newTextWatcher() {

privateCharSequencetemp;

private inteditStart;

private inteditEnd;

@Override

public voidbeforeTextChanged(CharSequence s,intarg1,intarg2,

intarg3) {

temp= s;

}

@Override

public voidonTextChanged(CharSequence s,intarg1,intarg2,

intarg3) {

mTextView.setText(s);

}

@Override

public voidafterTextChanged(Editable s) {

editStart=mEditText.getSelectionStart();

editEnd=mEditText.getSelectionEnd();

if(temp.length() >10) {

Toast.makeText(MainActivity.this,

"你輸入的字數已經超過了限制！", Toast.LENGTH_SHORT)

.show();

s.delete(editStart-1,editEnd);

inttempSelection =editStart;

mEditText.setText(s);

mEditText.setSelection(tempSelection);

}

}

};

}