具有水平线的多行Edittext(Multiline Edittext with Horizontal Lines)

 我正在制作一个作业不知道如何添加一个多行的edittext遵循这一个教程，但不知道如何在MainActivity类中实现它 
 
 在edittext中绘制多行，例如记事本 
 
 我正在使用以下课程 
 
public class LinedEditText extends EditText {

    private Rect mRect;
    private Paint mPaint;

    // we need this constructor for LayoutInflater
    public LinedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);

        mRect = new Rect();
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
      //  mPaint.setColor(getResources().getColor()); //SET YOUR OWN COLOR HERE
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //int count = getLineCount();

        int height = getHeight();
        int line_height = getLineHeight();

        int count = height / line_height;

        if (getLineCount() > count)
            count = getLineCount();//for long text with scrolling

        Rect r = mRect;
        Paint paint = mPaint;
        int baseline = getLineBounds(0, r);//first line

        for (int i = 0; i < count; i++) {

            canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
            baseline += getLineHeight();//next line
        }

        super.onDraw(canvas);
    }

}
 
 我有以下xml视图想要通过这个类inflat它们 
 
 activity_main.xml中 
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

</LinearLayout>
 
 multilinedittext.xml 
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/multiline_exdittext_layout"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:inputType="textMultiLine"
        android:ems="10"
        android:id="@+id/edittxt_multilines"
        />

</LinearLayout>

I am making a Assignment don't know how to add a multilines edittext follow this one Tutorial but don't know how to implement it in MainActivity class
 
Drawing multiple lines in edittext e.g. notepad
 
i am using following class 
 
public class LinedEditText extends EditText {

    private Rect mRect;
    private Paint mPaint;

    // we need this constructor for LayoutInflater
    public LinedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);

        mRect = new Rect();
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
      //  mPaint.setColor(getResources().getColor()); //SET YOUR OWN COLOR HERE
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //int count = getLineCount();

        int height = getHeight();
        int line_height = getLineHeight();

        int count = height / line_height;

        if (getLineCount() > count)
            count = getLineCount();//for long text with scrolling

        Rect r = mRect;
        Paint paint = mPaint;
        int baseline = getLineBounds(0, r);//first line

        for (int i = 0; i < count; i++) {

            canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
            baseline += getLineHeight();//next line
        }

        super.onDraw(canvas);
    }

}
 
and i have following xml view wanted to inflat them via this class
 
activity_main.xml
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

</LinearLayout>
 
multilinedittext.xml
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/multiline_exdittext_layout"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:inputType="textMultiLine"
        android:ems="10"
        android:id="@+id/edittxt_multilines"
        />

</LinearLayout>

原文：https://stackoverflow.com/questions/33341541