无法取得ENTER的preSS行号 [英] Unable to get line number on press of ENTER
问题描述
我有一个EditText上ENTER键我想调用一个函数,并转到下一行的preSS,我想有后pressing进入我的当前行的行号。
I have an edittext, on press of ENTER key i want to call a function and go to next line, and i want to have the line number of my current line after pressing enter.
我使用 edittext.onKeyListner
scene.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if ((event.getAction() == KeyEvent.ACTION_DOWN) &&
(keyCode == KeyEvent.KEYCODE_ENTER)) {
// Perform action on key press
String s = scene.getText().toString();
s= s + "\n";
scene.setText(s);
final int lineno = getCurrentCursorLine(scene);
//Log.v("lineno" , Integer.toString(lineno));
return true;
}
return false;
}
});
我试图用这个函数来获取行号
And i am trying to get line number using this function
public int getCurrentCursorLine(EditText editText)
{
int selectionStart = Selection.getSelectionStart(editText.getText());
Layout layout = editText.getLayout();
if (!(selectionStart == -1)) {
return layout.getLineForOffset(selectionStart);
}
return -1;
}
问题是,如果我不叫edittext.onKeyListner,那么它会给出正确的行数,但如果我叫edittext.onKeyListner它将返回异常
请大家帮忙
The problem is, if i do not call edittext.onKeyListner, then it will give the right line number but if i call edittext.onKeyListner it will return exception please help
这是我的logcat
here is my logcat
10-28 13:29:22.997: E/AndroidRuntime(20220): FATAL EXCEPTION: main
10-28 13:29:22.997: E/AndroidRuntime(20220): java.lang.NullPointerException
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.example.screenwritter.Newscene.getCurrentCursorLine(Newscene.java:150)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.example.screenwritter.Newscene$2.onKey(Newscene.java:126)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.View.dispatchKeyEvent(View.java:5558)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1349)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1349)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1349)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1349)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1884)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1366)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.app.Activity.dispatchKeyEvent(Activity.java:2324)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1811)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewRootImpl.deliverKeyEventPostIme(ViewRootImpl.java:3331)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2601)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.os.Handler.dispatchMessage(Handler.java:99)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.os.Looper.loop(Looper.java:137)
10-28 13:29:22.997: E/AndroidRuntime(20220): at android.app.ActivityThread.main(ActivityThread.java:4448)
10-28 13:29:22.997: E/AndroidRuntime(20220): at java.lang.reflect.Method.invokeNative(Native Method)
10-28 13:29:22.997: E/AndroidRuntime(20220): at java.lang.reflect.Method.invoke(Method.java:511)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
10-28 13:29:22.997: E/AndroidRuntime(20220): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
10-28 13:29:22.997: E/AndroidRuntime(20220): at dalvik.system.NativeStart.main(Native Method)
推荐答案
选择和看辛格运河钥匙我会用 TextWatcher
。这里有一个code片段添加到的onCreate
为多行的EditText
(我给id为编辑 )。
Instead of Selection
and watching singel keys I would use a TextWatcher
. Here's a code snippet to add to onCreate
for a multi line EditText
(I gave the id "edit").
((EditText) findViewById(R.id.edit)).addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
int lines = (s.length() > 0)? 1:0;
for(int i = 0; i < s.length(); i++)
if(s.charAt(i) == '\n') lines++;
Log.d("TEST", "lines now: " + lines);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
public void afterTextChanged(Editable s) {}
});
它记录行的logcat当前numbe。你可以用换行检测更加swofisticated,而是要说明如何实现它,这应该是好的。
It logs the current numbe of lines to logcat. You can be more swofisticated with the newline detection, but to show how to implement it, this should be ok.
这篇关于无法取得ENTER的preSS行号的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!