1、首先屏蔽 EditText 的软键盘

 2、EditText在光标下插入删除内容

clear.setOnClickListener(new OnClickListener() {   
    @Override
    public void onClick(View v) {
     int start = newPassword.getSelectionStart();
        int end = newPassword.getSelectionEnd();
     Toast.makeText(SetPasswordActivity.this, start+"-----"+end, Toast.LENGTH_LONG).show();
     if(start-1!=0){
      newPassword.getText().delete(start-1, end);
     }else{
      newPassword.getText().clear();
     }
    }   
   });

3、EditText光标移动

      Selection.setSelection(newPassword.getText(),newPassword.getText().length());

4、复制操作

ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);

clipboard.setText("Text to copy");

String data = clipboard.getText();

boolean isData = clipboard.hasText();