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在edittext中更改文本之前获取光标起始索引

textwatcher selection android-edittext android

Omar Boshra · 技术社区 · 7 年前

这可能看起来像一个简单的问题,但我不明白为什么会发生这种情况。我想在用户更改文本之前,在我的edittext中获取所选内容的开始和结束索引,因此在我的TextWatcher中,我做了如下操作:-

 public void beforeTextChanged(CharSequence s, int start, int count, int after) {


                    selectionStart = edittext.getSelectionStart();
                    selectionEnd = edittext.getSelectionEnd();


            }

但是,selectionStart和selectionEnd都返回所选内容的结束索引。例如,我选择了一个单词“ 你好

2 回复 | 直到 7 年前

Omar Boshra 7 年前

我终于找到了这个问题的解决方案,虽然有点难看,但最有效地解决了这个问题。问题是,在文本更改之前,文本选择已经消失,因此我必须使用处理程序等待文本被选择,然后使用范围观察程序立即设置选择,就像这样:-

final SpanWatcher watcher = new SpanWatcher() {
@Override
public void onSpanAdded(final Spannable text, final Object what,final int start, final int end) {

final Handler handler = new Handler();//handler to get selection after 
certain time
handler.postDelayed(new Runnable() {
@Override
public void run() {

if(noteview.hasSelection()) {

higlightdetect=1;//integer to detect that text was selected

selectionStart = noteview.getSelectionStart();
selectionEnd = noteview.getSelectionEnd();

                    }else
higlightdetect=0;
                }
            }, 600);//after 600ms seemed to be the optimal time after selection occurs
        }
}

@Override
public void onSpanRemoved(final Spannable text, final Object what,
                                  final int start, final int end) {
            // Nothing here.
        }

@Override
public void onSpanChanged(final Spannable text, final Object 
what,final int ostart, final int oend, final int nstart, final int nend) 
{
//The same

final Handler handler = new Handler();//handler to get selection after 
certain time
handler.postDelayed(new Runnable() {
@Override
public void run() {

if(noteview.hasSelection()) {

higlightdetect=1;//integer to detect that text was selected

selectionStart = noteview.getSelectionStart();
selectionEnd = noteview.getSelectionEnd();

                    }else
higlightdetect=0;
                }
            }, 600);//after 600ms seemed to be the optimal time after selection occurs
        }
};


edittext.getText().setSpan(watcher, 0, edittext.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);//set spanwatcher to edittext

@Override
public void beforeTextChanged(CharSequence s, int start, int 
count, int after) {



if(higlightdetect==0){//condition to get cursor position without selection

selectionStart = noteview.getSelectionStart();
selectionEnd=selectionStart;
}
public void onTextChanged(CharSequence s, int start, int before, int 
count) {

        }

@Override
public void afterTextChanged(Editable s) {

Toast.makeText(getthenote.this, String.valueOf(selectionStart), 
Toast.LENGTH_SHORT).show();
Toast.makeText(getthenote.this, String.valueOf(selectionEnd), 
Toast.LENGTH_SHORT).show();

higlightdetect=0 //resetting higlightdetect
}

htafoya 5 年前

你为什么不直接使用 start 中的参数 beforeTextChanged 方法