继承edittext，系统绘制时会在canvas上处理好在正常状态下的EditText内容，咱们获取到行的位置信息，向画板的行的下方添加线条即可，详情见onDraw方法。
import android.content.Context;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.EditText;
/** 行之间有分隔线的edittext */
public class DividerEditText extends EditText {
private Rect mRect;
private Paint mPaint;
private static final int mLineColor = Color.RED;
private static final int mLineHeight = 3;
public DividerEditText(Context context) {
super(context);
init();
}
public DividerEditText(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public DividerEditText(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
mRect = new Rect();
mPaint = new Paint();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setColor(mLineColor);
mPaint.setStrokeWidth(mLineHeight);
}
protected void onDraw(android.graphics.Canvas canvas) {
//先由系统绘制好正常的界面
super.onDraw(canvas);
//获取基本的位置信息
int count = getLineCount();
Rect r = mRect;
Paint paint = mPaint;
//循环在每个行的下面绘制一条横线
for (int i = 0; i < count - 1; i++) {
int baseline = getLineBounds(i, r);
canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
}
};
}
