我是Android的新手，我很难在我的应用上找到问题的解决方案。
我的应用是一款wordsearch游戏，使用点击图块作为输入。这是tablelayout上动态 textviews 的onClick()代码：
text.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
w.setVisibility(View.VISIBLE);
//change the color of tapped textview
text.setTextColor(Color.WHITE);
text.setBackgroundColor(Color.parseColor(mColors[randomNum]));
String b = text.getText().toString();
uTxt.setText(""+uTxt.getText().toString() + b);
//check if answer is in the word grid
if(checkAns(uTxt, list))
{
w.setVisibility(View.GONE);
wC.setText(String.valueOf(Integer.parseInt(wC.getText()+"")-1));
if(Integer.parseInt(wC.getText()+"") == 0){
int newM = minutes*60 + seconds;
dataHelper.insertData(pNameC.getText().toString(), newM, currentDateandTime, Category.leve);
t.cancel();
Context mContext = getApplicationContext();
Activity mActivity = GameScreen.this;
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
// Inflate the custom layout/view
View customView = inflater.inflate(R.layout.gameover,null);
// Initialize a new instance of popup window
PopupWindow mPopupWindow = new PopupWindow(
customView,
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.WRAP_CONTENT
);
Typeface font = Typeface.createFromAsset(getAssets(), "raw2.ttf");
TextView cattxt = (TextView)customView.findViewById(R.id.catTxt);
String ctg = ti.getText().toString();
cattxt.setTypeface(font);
cattxt.setText(ctg);
Button yesB = (Button) customView.findViewById(R.id.maglaro2);
yesB.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(GameScreen.this, Category.class);
startActivity(intent);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
GameScreen.this.finish();
}
});
Button noB = (Button) customView.findViewById(R.id.hindi);
noB.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(GameScreen.this, MainActivity.class);
startActivity(intent);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
GameScreen.this.finish();
}
});
mPopupWindow.showAtLocation(table, Gravity.CENTER,0,0);
}
uTxt.setText("");
}
}
});
现在我的问题是我想要一个UNDO按钮，它会删除uTxt上的最后一个字符，并会更改上次触摸的textView的颜色
有没有人对如何做到这一点有任何想法？
如果是，请在下面留下评论，回答或建议。 TIA！