Android:自定义View、Paint、Canvas、attrs、customview、path

简介:

第一种:oncreate里启动自定义view


Activity代码:

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import  android.os.Bundle;
import  android.app.Activity;
import  android.view.Menu;
public  class  MainActivity  extends  Activity
{
     /**
      * 两种方法:
      * 1.直接在layout里找到自定义控件
      * 2.oncreate里启动自定义view
      */
     @Override
     protected  void  onCreate(Bundle savedInstanceState)
     {
         super .onCreate(savedInstanceState);
                                                                                                                                                                          
         //先new一个自定义view对象
         VerticalTextView view =  new  VerticalTextView( this );
         setContentView(view);
//        setContentView(R.layout.activity_main);
     }
                                                                                                                                                                      
     @Override
     public  boolean  onCreateOptionsMenu(Menu menu)
     {
         getMenuInflater().inflate(R.menu.main, menu);
         return  true ;
     }
                                                                                                                                                                      
}



View类代码:

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import  android.content.Context;
import  android.graphics.Bitmap;
import  android.graphics.BitmapFactory;
import  android.graphics.Canvas;
import  android.graphics.Color;
import  android.graphics.Paint;
import  android.view.View;
public  class  VerticalTextView  extends  View
{
     //定义一个自定义角度的文本
     private  Paint mPaint;
     public  VerticalTextView(Context context)
     {
         super (context);
         init();
     }
                                                                                                                                                     
     private  void  init()
     {
         mPaint =  new  Paint();
         mPaint.setColor(Color.BLUE);
         mPaint.setTextSize( 50 );
         mPaint.setAntiAlias( true ); //设置抗锯齿
     }
     @Override
     protected  void  onDraw(Canvas canvas)
     {
         super .onDraw(canvas);
         Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
                                                                                                                                                         
         canvas.rotate( 75 );
//        canvas.rotate(60,bitmap.getWidth()*2 , bitmap.getHeight()*2);
         canvas.drawText( "CanvasHello" 0 0 , mPaint);
         canvas.drawBitmap(bitmap,  0 0 , mPaint);
     }
                                                                                                                                                     
}



第二种:直接在layout里找到自定义控件(直接新建custom view)

1.新建attrs文件,增加自定义属性:

增加属性内容:

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<declare-styleable name= "LabelView" >
<attr name= "text"  format= "string"  />
<attr name= "textColor"  format= "color"  />
<attr name= "textSize"  format= "dimension"  />
</declare-styleable>

或者:

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<declare-styleable name= "DraggableDot" >
<attr name= "radius"  format= "dimension"  />
<attr name= "legend"  format= "string"  />
<attr name= "anr" >
     < enum  name= "none"  value= "0"  />
     < enum  name= "thumbnail"  value= "1"  />
     < enum  name= "drop"  value= "2"  />
</attr>
</declare-styleable>

范例:

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<resources>
     <declare-styleable name= "MyView" >
         <attr name= "mytext"  format= "string"  />
         <attr name= "mytextColor"  format= "color"  />
         <attr name= "mytextSize"  format= "dimension"  />
     </declare-styleable>
</resources>


2.增加自己的命名空间,将android修改为自己的包名:

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<RelativeLayout xmlns:android= "http://schemas.android.com/apk/res/android"
xmlns:MyView= "http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"


3.在layout中创建自定义view,设置自定义属性(控件包名记得修改):

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<com.example.aexh23_paint_canvas.VerticalTextView
android:id= "@+id/verticalTextView1"
android:layout_width= "wrap_content"
android:layout_height= "wrap_content"
MyView:mytext= "HelloWorld"
MyView:mytextColor= "#654321"
MyView:mytextSize= "35sp"
android:layout_centerHorizontal= "true"
android:layout_centerVertical= "true"  />


范例:

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<RelativeLayout xmlns:android= "http://schemas.android.com/apk/res/android"
     xmlns:MyView= "http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"
     xmlns:tools= "http://schemas.android.com/tools"
     android:layout_width= "match_parent"
     android:layout_height= "match_parent"
     tools:context= ".MainActivity"  >
     <com.example.aexh23_paint_canvas.VerticalTextView
         android:id= "@+id/verticalTextView1"
         android:layout_width= "wrap_content"
         android:layout_height= "wrap_content"
         MyView:mytext= "HelloWorld"
         MyView:mytextColor= "#654321"
         MyView:mytextSize= "35sp"
         android:layout_centerHorizontal= "true"
         android:layout_centerVertical= "true"  />
</RelativeLayout>


4.在自定义view类中增加方法:

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setTextColor(a.getColor(R.styleable.LabelView_textColor,  0xFF000000 ));
int  textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize,  0 );
if  (textSize >  0 ) {
     setTextSize(textSize);
}


范例:

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public  class  VerticalTextView  extends  View
{
     /**
      * 系统范例:LabelView
      * 1.新建attrs文件,增加属性:
         <declare-styleable name="LabelView">
         <attr name="text" format="string" />
         <attr name="textColor" format="color" />
         <attr name="textSize" format="dimension" />
         </declare-styleable>
         //////////////////////////////////////////////
         <declare-styleable name="DraggableDot">
         <attr name="radius" format="dimension" />
         <attr name="legend" format="string" />
         <attr name="anr">
             <enum name="none" value="0" />
             <enum name="thumbnail" value="1" />
             <enum name="drop" value="2" />
         </attr>
         </declare-styleable>
         ////////////////////////////////////////////////
                             
         2.增加自己的命名空间,将android修改为自己的包名
         <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:MyView="http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"
                             
         3.在layout中创建自定义view,增加属性
         <com.example.aexh23_paint_canvas.VerticalTextView
         android:id="@+id/verticalTextView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         MyView:mytext="HelloWorld"
         MyView:mytextColor="#654321"
         MyView:mytextSize="35sp"
         android:layout_centerHorizontal="true"
         android:layout_centerVertical="true" />
                             
         4.在自定义view类中增加方法
         setTextColor(a.getColor(R.styleable.LabelView_textColor, 0xFF000000));
         int textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize, 0);
         if (textSize > 0) {
             setTextSize(textSize);
         }
                             
      */
     private  Paint mPaint;
     private  CharSequence s;
     private  int  c;
     private  int  d;
                         
                         
     public  VerticalTextView(Context context, AttributeSet attrs)
     {
         super (context, attrs);
         TypedArray a = context.obtainStyledAttributes(attrs,
                 R.styleable.MyView);
         s = a.getString(R.styleable.MyView_mytext);
         c = a.getColor(R.styleable.MyView_mytextColor,  0xFF000000 );
         d = a.getDimensionPixelOffset(R.styleable.MyView_mytextSize,  0 );
         init();
         a.recycle();
     }
                         
     //定义画笔
     private  void  init()
     {
         mPaint =  new  Paint();
         mPaint.setColor(c );
         mPaint.setTextSize(d);
         mPaint.setAntiAlias( true ); // 设置抗锯齿
     }
                         
     @Override
     protected  void  onDraw(Canvas canvas)
     {
         super .onDraw(canvas);
         Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
                             
         canvas.rotate( 30 );
         // canvas.rotate(60,bitmap.getWidth()*2 , bitmap.getHeight()*2);
         canvas.drawText(s.toString(),  0 0 , mPaint);
         canvas.drawBitmap(bitmap,  0 0 , mPaint);
                             
     }
}





本文转自 glblong 51CTO博客,原文链接:http://blog.51cto.com/glblong/1228552,如需转载请自行联系原作者

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