Android- EditText与InputFilter兑现文本对比

????? 此功能类似于临摹。已知被临摹的字符串，将字符串与EditText中输入进行

对比，输入错误，则用“×”替换所输入的字符。

import android.app.Activity;import android.os.Bundle;import android.text.InputFilter;import android.text.Spanned;import android.util.Log;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;public class MyFilterTest extends Activity {    /** Called when the activity is first created. */	TextView myText;	EditText myEdit;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        final String str = "Hello,Android!";                myText=(TextView)findViewById(R.id.myText);        myText.setText(str);        myEdit=(EditText)findViewById(R.id.myEdit);                myEdit.setFilters(new InputFilter[]{ new MyInputFilter(str) });            }    public class MyInputFilter implements InputFilter{    	String str=null;    	public MyInputFilter(String str){    		this.str=str;    	}		@Override		public CharSequence filter(CharSequence src, int start, int end,				Spanned dest, int dstart, int dend) {			// TODO Auto-generated method stub			String ch=null;			String TAG="Filter";			Log.w(TAG,"src:"+src+";start:"+start+";end:"+end);			Log.w(TAG,"dest:"+dest+";dstart:"+dstart+";dend:"+dend);	        if(dest.length()<str.length()){	        	ch=str.substring(dstart+start, dstart+end);	        }else{	        	return dest.subSequence(dstart, dend);	        }	        		        if(ch.equals(src)){	        	        	Toast.makeText(MyFilterTest.this, "match", Toast.LENGTH_SHORT).show();				return dest.subSequence(dstart, dend)+src.toString();			}else{				Toast.makeText(MyFilterTest.this, "mismatch", Toast.LENGTH_SHORT).show();				return dest.subSequence(dstart, dend)+"×";			}		}    	    	    }}

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