Android ToDoList (custom style) detailed

Android allows you to derive subclasses from the existing View toolbox (Widget Tool Box) or implement your own view controls;

By overriding the event handlers and the OnDraw () method, but still recalling the superclass (super) method, you can customize the view without having to have its features solid;

Predecessor steps See: http://blog.csdn.net/caroline_wendy/article/details/21246963

Steps:

1. Create a Todolistitemview class that customizes the appearance of item items:

Location: Java->package->todolistitemview.java

Package Mzx.spike.todolist.app;  
Import Android.content.Context;  
Import android.content.res.Resources;  
Import Android.graphics.Canvas;  
Import Android.graphics.Paint;  
Import Android.util.AttributeSet;  
      
Import Android.widget.TextView; 
 /** * Created by C.l.wang on 14-3-16.  
    * * public class Todolistitemview extends textview{private Paint marginpaint;  
    Private Paint Linepaint;  
    private int papercolor;  
      
    private float margin;  
        Public Todolistitemview (context, attributeset ATS, int ds) {Super (context, ATS, DS);  
    Init ();  
        Public Todolistitemview {Super (context);  
    Init ();  
        Public Todolistitemview (context, AttributeSet ATS) {Super (context, ATS);  
    Init (); 
        private void Init () {//Get a reference to the resource list//See more Highlights in this column: http://www.bianceng.cn/OS/extra/ Resources myresources = Getresources ();  
        Marginpaint = new Paint (Paint.anti_alias_flag);  
      
        Marginpaint.setcolor (Myresources.getcolor (R.color.notepad_margin));  
        Linepaint = new Paint (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);  
      
        @Override public void OnDraw (Canvas Canvas) {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 (); }  
      
}

Detailed

1. Inherits the TextView class, is the text view customization;

2. Overloaded constructors, containing overloaded versions of three parameters, and after callback superclass (super), initialize the resource private variable (init);

3. In init (), obtain a reference to the resource list (getresource), convert the resource file to a callable parameter (MYRESOURCE.GETXXX), and initialize the resource private variable;

4. Rewrite (Override) OnDraw method, set color, draw line, specify write format;

5. Canvas.translate (), so that the output file, the margin distance after moving;

2. Create a color (colors) resource file

Location: Res->values->colors.xml

<?xml version= "1.0" encoding= "Utf-8"?>  
<resources>  
    <color name= "Notepad_paper" ># eef8e0a0</color>  
    <color name= "Notepad_lines" > #FF0000FF </color>  
    <color name= "notepad _margin "> #90FF0000 </color>  
    <color name=" Notepad_text "> #AA0000FF </color>  
</ Resources>

Color resource files, with color tags, Android studio will display colors;

3. Modify the size (dimen) resource file:

Location: Res->values->dimen.xml

<resources>  
    <!--Default screen margins, per the Android guidelines-->
    <dimen name= " Activity_horizontal_margin ">16dp</dimen>  
    <dimen name=" Activity_vertical_margin ">16dp</ dimen>  
    <dimen name= "Notepad_margin" >30dp</dimen>  
</resources>

Supplement can be;

4. Create Todolist_item Layout file:

Location: Res->layout->todolist_item.xml

<?xml version= "1.0" encoding= "Utf-8"?> <mzx.spike.todolist.app.todolistitemview xmlns:android=
    " Http://schemas.android.com/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 "
 />"

Detailed

1. The label is class name, namely Todolistitemview class, overload the method of TextView;

2. Set the corresponding attribute label;

5. Modify the adapter (Adapter) and use the customized TextView:

Location: java->package->todolistactivity

......  
        int resid = R.layout.todolist_item;  
        Three parameter  
        AA = new Arrayadapter<string> (this, resid, todoitems);  
      
        Todolistfragment.setlistadapter (AA);  
......

Detailed

Locate the ID of the resource file, incoming adapter;

6. Executing program: Code download: http://download.csdn.net/detail/u012515223/7050371

Author: csdn Blog spike_king