Android 避免二个相互影响的 EditText 死循环

两个EditText同时设置TextChangedListener后，会使程序进入死循环，解决方法如下：

		etExchangeRateEn = (EditText) findViewById(R.id.etExchangeRateEn);		etExchangeRateCn = (EditText) findViewById(R.id.etExchangeRateCn);		twEN = new TextWatcher()		{			@Override			public void afterTextChanged(Editable s)			{				etExchangeRateCn.addTextChangedListener(twCN);			}			@Override			public void beforeTextChanged(CharSequence s, int start, int count, int after)			{			}			@Override			public void onTextChanged(CharSequence s, int start, int before, int count)			{				etExchangeRateCn.setText( "CN");			}		};		twCN = new TextWatcher()		{			@Override			public void afterTextChanged(Editable s)			{				etExchangeRateEn.addTextChangedListener(twEN);			}			@Override			public void beforeTextChanged(CharSequence s, int start, int count, int after)			{			}			@Override			public void onTextChanged(CharSequence s, int start, int before, int count)			{				etExchangeRateEn.setText("EN");			}		};		etExchangeRateEn.addTextChangedListener(twEN);		etExchangeRateCn.addTextChangedListener(twCN);