Android开发：自定义记事本样式EditText

实现代码如下：

主方法，main.java

import java.text.SimpleDateFormat;
import java.util.Date;

import Android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class Main extends Activity {
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  LinearLayout layout = new LinearLayout(this);
  layout.setOrientation(LinearLayout.VERTICAL);
  MyNote mn = new MyNote(this);
  mn.setHeight(380);
  layout.addView(mn);
 
  LinearLayout layout1=new LinearLayout(this);
  layout1.setOrientation(LinearLayout.HORIZONTAL);
  Button button = new Button(this);
  button.setText("确定");
  button.setWidth(60);
  layout1.addView(button);
 
  TextView textview=new TextView(this);
  Date date=new Date();
  SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
  String dateString=sdf.format(date);
  textview.setText(dateString);
  textview.setWidth(200);
  textview.setPadding(60, 0, 0, 0);
  layout1.addView(textview);
 
  Button button1=new Button(this);
  button1.setText("取消");
  button1.setWidth(60);
  layout1.addView(button1);
 
  layout.addView(layout1);
 
  this.setContentView(layout);

}
}

主方法中主要实现了整个画布的布局的简单设置。以下是自定义EditText的具体实现方法。

MyNote.java

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.Gravity;
import android.widget.EditText;

public class MyNote extends EditText{

public MyNote(Context context) {
  super(context);
  // TODO Auto-generated constructor stub
 }

protected void onDraw(Canvas canvas){
  int lineHeight=this.getLineHeight();
  Paint mPaint=getPaint();
  mPaint.setColor(Color.GRAY);//文本编辑线
  int topPadding=this.getPaddingTop();
  int leftPadding=this.getPaddingLeft();
  float textSize=getTextSize();
  setGravity(Gravity.LEFT|Gravity.TOP);
  int y =(int)(topPadding+textSize);
  for(int i=0;i<getLineCount();i++){
   canvas.drawLine(leftPadding, y+2, getRight()-leftPadding, y+2, mPaint);
   y+=lineHeight;
  }
  canvas.translate(0, 0);
  super.onDraw(canvas);
 }
}