Android：自定义View、Paint、Canvas、attrs、customview、path
第一种：oncreate里启动自定义view Activity代码： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 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： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 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： 1 2 3 4 5 <declare-styleable name= "LabelView" > <attr name= "text" format= "string" /> <attr name= "textColor" format= "color" /> <attr name= "textSize" format= "dimension" /> </declare-styleable> 或者： 1 2 3 4 5 6 7 8 9 <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： 1 2 3 4 5 6 7 <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： 1 2 <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）： 1 2 3 4 5 6 7 8 9 <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： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 <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: 1 2 3 4 5 setTextColor(a.getColor(R.styleable.LabelView_textColor, 0xFF000000 )); int textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize, 0 ); if (textSize > 0 ) { setTextSize(textSize); } 范例： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 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
