简单来说，是一个类似如下的需求：
两个EditText，假设名字分别是 et1和et2;et1的值*一个数字，假设是4500=et2的值；
当 et1 的值发生变化时，et2 的值也发生变化，et2的值发生变化时，et1的值也发生变化，
用过用简单的 TextWatcher 就会发生死循环，如何避免，下面是这个例子代码的最核心部分，简单来说就是在一个事件起效果时，另外一个事件注销。
private int v1 = 4500;
private EditText et1, et2;
private TextWatcher tw1, tw2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
et1 = (EditText) findViewById(R.id.editText1);
et2 = (EditText) findViewById(R.id.editText2);
et1.setText("3");
et2.setText("13500");
tw1 = new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,int count) {
et2.removeTextChangedListener(tw2);
int et1val = 0;
try {
et1val =Integer.parseInt(s.toString());
} catch (Exception ex) {
et1val = 0;
}
Log.i("eee1", ""+et1val);
int et2val = et1val * v1;
et2.setText("" + et2val);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,int after) {
}
@Override
public void afterTextChanged(Editable s) {
et2.addTextChangedListener(tw2);
}
};
tw2 = new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,int count) {
et1.removeTextChangedListener(tw1);
int et2val = 0;
try {
et2val = Integer.parseInt(s.toString());
} catch (Exception ex) {
et2val = 0;
}
Log.i("eee2", ""+et2val);
int et1val = et2val / v1;
et1.setText("" + et1val);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,int after) {
}
@Override
public void afterTextChanged(Editable s) {
et1.addTextChangedListener(tw1);
}
};
et1.addTextChangedListener(tw1);
et2.addTextChangedListener(tw2);
}