【移动应用开发技术】Android - ToDoList(定制样式) 详解

【移动应用开发技术】Android-ToDoList(定制样式)详解

ToDoList(定制样式)详解本文地址:

/caroline_wendy/article/details/21330733Android允许从已有的视图工具箱(WidgetToolBox)派生子类或实现自己的视图控件;通过重写事件处理程序和onDraw()方法,但是仍然回调超类(super)的方法,可以对视图进行定制,而不必实心它的功能;前置步骤参见:

/caroline_wendy/article/details/21246963步骤:

位置:java->package->ToDoListItemView.javapackagemzx.spike.todolist.app;importandroid.content.Context;importandroid.content.res.Resources;importandroid.graphics.Canvas;importandroid.graphics.Paint;importandroid.util.AttributeSet;importandroid.widget.TextView;/***CreatedbyC.L.Wangon14-3-16.*/publicclassToDoListItemViewextendsTextView{privatePaintmarginPaint;privatePaintlinePaint;privateintpaperColor;privatefloatmargin;publicToDoListItemView(Contextcontext,AttributeSetats,intds){super(context,ats,ds);init();}publicToDoListItemView(Contextcontext){super(context);init();}publicToDoListItemView(Contextcontext,AttributeSetats){super(context,ats);init();}privatevoidinit(){//获得对资源列表的引用ResourcesmyResources=getResources();marginPaint=newPaint(Paint.ANTI_ALIAS_FLAG);marginPaint.setColor(myResources.getColor(R.color.notepad_margin));linePaint=newPaint(Paint.ANTI_ALIAS_FLAG);linePaint.setColor(myResources.getColor(R.color.notepad_lines));paperColor=myResources.getColor(R.color.notepad_paper);margin=myResources.getDimension(R.dimen.notepad_margin);}@OverridepublicvoidonDraw(Canvascanvas){canvas.drawColor(paperColor);canvas.drawLine(0,0,0,getMeasuredHeight(),linePaint);canvas.drawLine(0,getMeasuredHeight(),getMeasuredWidth(),getMeasuredHeight(),linePaint);canvas.drawLine(margin,0,margin,getMeasuredHeight(),marginPaint);canvas.save();canvas.translate(margin,0);super.onDraw(canvas);canvas.restore();}}1.继承TextView类,是文本视图的定制;2.重载构造函数,包含三个参数的重载版本,回调超类(super)之后,初始化资源私有变量(init);3.在Init()中,获得资源列表的引用(getResource),将资源文件转换为可以调用的参数(myResource.getXXX),初始化资源私有变量;4.重写(Override)OnDraw方法,设置颜色,画线,指定写入格式;5.canvas.translate(),使输出文件,后移margin距离;位置:res->values->colors.xml<?xmlversion="1.0"encoding="utf-8"?><resources><colorname="notepad_paper">#EEF8E0A0</color><colorname="notepad_lines">#FF0000FF</color><colorname="notepad_margin">#90FF0000</color><colorname="notepad_text">#AA0000FF</color></resources>位置:

res->values->dimen.xml<resources><!--Defaultscreenmargins,pertheAndroidDesignguidelines.--><dimenname="activity_horizontal_margin">16dp</dimen><dimenname="activity_vertical_margin">16dp</dimen><dimenname="notepad_margin">30dp</dimen></resources>位置:res->layout->todolist_item.xml<?xmlversion="1.0"encoding="utf-8"?><mzx.spike.todolist.app.ToDoListItemViewxmlns:android="/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent"android:padding="10dp"android:scrollbars="vertical"android:textColor="@color/notepad_text"android:fadingEdge="vertical"/>1.标签为类名,即ToDoListItemView类,重载了TextView的方法;2.设置相应的属性标签;位置:java->package->ToDoListActivityintresID=R.layout.todolist_item;//三个参数aa=newArrayAd