1、有关AndroidUI开发专题完整版有关Android UI开发专题之界面设计近期很多网友对Android用户界面的设计表示很感兴趣,对于Android UI开发自绘控件和游戏制作而言掌握好绘图基础是必不可少的。本次专题分10节来讲述,有关OpenGL ES相关的可能将放到以后再透露。本次主要涉及以下四个包的相关内容:android.content.res 资源类android.graphics 底层图形类android.view 显示类android.widget 控件类一、android.content.res.Resources对于Android平台的资源类android.content
2、.res.Resources可能很多网友比较陌生,一起来看看SDK上是怎么介绍的吧,Contains classes for accessing application resources, such as raw asset files, colors, drawables, media or other other files in the package, plus important device configuration details (orientation, input types, etc.) that affect how the application may beha
3、ve.平时用到的二进制源文件raw、颜色colors、图形drawables和多媒体文件media的相关资源均通过该类来管理。int getColor(int id) 对应res/values/colors.xmlDrawable getDrawable(int id) 对应res/drawable/XmlResourceParser getLayout(int id) 对应res/layout/String getString(int id) 和CharSequence getText(int id) 对应res/values/strings.xmlInputStream openRawRe
4、source(int id) 对应res/raw/void parseBundleExtra (String tagName, AttributeSet attrs, Bundle outBundle) 对应res/xml/String getStringArray(int id) res/values/arrays.xmlfloat getDimension(int id) res/values/dimens.xml二、android.graphics.Bitmap作为位图操作类,Bitmap提供了很多实用的方法,常用的我们总结如下:boolean compress(Bitmap.Compr
5、essFormat format, int quality, OutputStream stream) 压缩一个Bitmap对象根据相关的编码、画质保存到一个OutputStream中。其中第一个压缩格式目前有JPG和PNGvoid copyPixelsFromBuffer(Buffer src) 从一个Buffer缓冲区复制位图像素void copyPixelsToBuffer(Buffer dst) 将当前位图像素内容复制到一个Buffer缓冲区我们看到创建位图对象createBitmap包含了6种方法在目前的Android 2.1 SDK中,当然他们使用的是API Level均为1,所以
6、说从Android 1.0 SDK开始就支持了,所以大家可以放心使用。static Bitmap createBitmap(Bitmap src)static Bitmap createBitmap(int colors, int width, int height, Bitmap.Config config)static Bitmap createBitmap(int colors, int offset, int stride, int width, int height, Bitmap.Config config)static Bitmap createBitmap(Bitmap sou
7、rce, int x, int y, int width, int height, Matrix m, boolean filter)static Bitmap createBitmap(int width, int height, Bitmap.Config config)static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height)static Bitmap createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean fi
8、lter) /创建一个可以缩放的位图对象final int getHeight() 获取高度final int getWidth() 获取宽度final boolean hasAlpha() 是否有透明通道void setPixel(int x, int y, int color) 设置某像素的颜色int getPixel(int x, int y) 获取某像素的颜色,android开发网提示这里返回的int型是color的定义三、android.graphics.BitmapFactory作为Bitmap对象的I/O类,BitmapFactory类提供了丰富的构造Bitmap对象的方法,比如
9、从一个字节数组、文件系统、资源ID、以及输入流中来创建一个Bitmap对象,下面本类的全部成员,除了decodeFileDescriptor外其他的重载方法都很常用。static Bitmap decodeByteArray(byte data, int offset, int length) /从字节数组创建static Bitmap decodeByteArray(byte data, int offset, int length, BitmapFactory.Options opts)static Bitmap decodeFile(String pathName, BitmapFact
10、ory.Options opts) /从文件创建,路径要写全static Bitmap decodeFile(String pathName)static Bitmap decodeFileDescriptor(FileDescriptor fd, Rect outPadding, BitmapFactory.Options opts) /从输入流句柄创建static Bitmap decodeFileDescriptor(FileDescriptor fd)static Bitmap decodeResource(Resources res, int id) /从Android的APK文件资
11、源中创建,android123提示是从/res/的drawable中static Bitmap decodeResource(Resources res, int id, BitmapFactory.Options opts)static Bitmap decodeResourceStream(Resources res, TypedValue value, InputStream is, Rect pad, BitmapFactory.Options opts)static Bitmap decodeStream(InputStream is) /从一个输入流中创建static Bitmap
12、 decodeStream(InputStream is, Rect outPadding, BitmapFactory.Options opts)四、android.graphics.Canvas从J2ME MIDLET时我们就知道Java提供了Canvas类,而目前在Android平台中,它主要任务为管理绘制过程,The Canvas class holds the draw calls. To draw something, you need 4 basic components: A Bitmap to hold the pixels, a Canvas to host the dra
13、w calls (writing into the bitmap), a drawing primitive (e.g. Rect, Path, text, Bitmap), and a paint (to describe the colors and styles for the drawing).该类主要提供了三种构造方法,分别为构造一个空的Canvas、从Bitmap中构造和从GL对象中创建,如下Canvas()Canvas(Bitmap bitmap)Canvas(GL gl)同时Canvas类的一些字段保存着重要的绘制方法定义,比如Canvas.HAS_ALPHA_LAYER_SA
14、VE_FLAG 保存时需要alpha层,对于Canvas类提供的方法很多,每个都很重要,下面我们一一作介绍boolean clipPath(Path path)boolean clipPath(Path path, Region.Op op)boolean clipRect(float left, float top, float right, float bottom)boolean clipRect(Rect rect)boolean clipRect(float left, float top, float right, float bottom, Region.Op op)boolea
15、n clipRect(Rect rect, Region.Op op)boolean clipRect(RectF rect)boolean clipRect(RectF rect, Region.Op op)boolean clipRect(int left, int top, int right, int bottom)boolean clipRegion(Region region, Region.Op op)boolean clipRegion(Region region)void concat(Matrix matrix)void drawARGB(int a, int r, int
16、 g, int b)void drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter, Paint paint)void drawBitmap(Bitmap bitmap, Matrix matrix, Paint paint)void drawBitmap(int colors, int offset, int stride, float x, float y, int width, int height, boolean hasAlpha, Paint paint)void drawBitmap(B
17、itmap bitmap, Rect src, Rect dst, Paint paint)void drawBitmap(Bitmap bitmap, float left, float top, Paint paint)void drawBitmap(int colors, int offset, int stride, int x, int y, int width, int height, boolean hasAlpha, Paint paint)void drawBitmap(Bitmap bitmap, Rect src, RectF dst, Paint paint)void
18、drawBitmapMesh(Bitmap bitmap, int meshWidth, int meshHeight, float verts, int vertOffset, int colors, int colorOffset, Paint paint)void drawCircle(float cx, float cy, float radius, Paint paint)void drawColor(int color)void drawColor(int color, PorterDuff.Mode mode)void drawLine(float startX, float s
19、tartY, float stopX, float stopY, Paint paint)void drawLines(float pts, Paint paint)void drawLines(float pts, int offset, int count, Paint paint)void drawOval(RectF oval, Paint paint)void drawPaint(Paint paint)void drawPath(Path path, Paint paint)void drawPicture(Picture picture, RectF dst)void drawP
20、icture(Picture picture, Rect dst)void drawPicture(Picture picture)void drawPoint(float x, float y, Paint paint)void drawPoints(float pts, int offset, int count, Paint paint)void drawPoints(float pts, Paint paint)void drawPosText(char text, int index, int count, float pos, Paint paint)void drawPosTex
21、t(String text, float pos, Paint paint)void drawRGB(int r, int g, int b)void drawRect(RectF rect, Paint paint)void drawRect(float left, float top, float right, float bottom, Paint paint)void drawRect(Rect r, Paint paint)void drawRoundRect(RectF rect, float rx, float ry, Paint paint)void drawText(Stri
22、ng text, int start, int end, float x, float y, Paint paint)void drawText(char text, int index, int count, float x, float y, Paint paint)void drawText(String text, float x, float y, Paint paint)void drawText(CharSequence text, int start, int end, float x, float y, Paint paint)void drawTextOnPath(Stri
23、ng text, Path path, float hOffset, float vOffset, Paint paint)void drawTextOnPath(char text, int index, int count, Path path, float hOffset, float vOffset, Paint paint)void drawVertices(Canvas.VertexMode mode, int vertexCount, float verts, int vertOffset, float texs, int texOffset, int colors, int c
24、olorOffset, short indices, int indexOffset, int indexCount, Paint paint)static void freeGlCaches()boolean getClipBounds(Rect bounds)final Rect getClipBounds()int getDensity()DrawFilter getDrawFilter()GL getGL()int getHeight()void getMatrix(Matrix ctm)final Matrix getMatrix()int getSaveCount()int get
25、Width()boolean isOpaque()boolean quickReject(Path path, Canvas.EdgeType type)boolean quickReject(float left, float top, float right, float bottom, Canvas.EdgeType type)boolean quickReject(RectF rect, Canvas.EdgeType type)void restore()void restoreToCount(int saveCount)final void rotate(float degrees
26、, float px, float py)void rotate(float degrees)int save()int save(int saveFlags)int saveLayer(float left, float top, float right, float bottom, Paint paint, int saveFlags)int saveLayer(RectF bounds, Paint paint, int saveFlags)int saveLayerAlpha(float left, float top, float right, float bottom, int a
27、lpha, int saveFlags)int saveLayerAlpha(RectF bounds, int alpha, int saveFlags)final void scale(float sx, float sy, float px, float py)void scale(float sx, float sy)void setBitmap(Bitmap bitmap)void setDensity(int density)void setDrawFilter(DrawFilter filter)void setMatrix(Matrix matrix)void setViewp
28、ort(int width, int height)void skew(float sx, float sy)void translate(float dx, float dy)五、android.graphics.Color有关Android平台上表示颜色的方法有很多种,Color提供了常规主要颜色的定义比如Color.BLACK和Color.GREEN等等,我们平时创建时主要使用以下静态方法static int argb(int alpha, int red, int green, int blue) 构造一个包含透明对象的颜色static int rgb(int red, int gre
29、en, int blue) 构造一个标准的颜色对象static int parseColor(String colorString) 解析一种颜色字符串的值,比如传入Color.BLACK本类返回的均为一个整形类似 绿色为0xff00ff00,红色为0xffff0000。我们将这个DWORD型看做AARRGGBB,AA代表Aphla透明色,后面的就不难理解,每个分成WORD整好为0-255。Android UI开发专题(二) 之绘图基础今天我们继续介绍Android平台底层绘图类的相关内容,在Android UI开发专题(一) 之界面设计中我们介绍了有关Android平台资源使用以及Bitma
30、p相关类的操作,接下来将会以实例的方式给大家演示各种类的用处以及注意点。今天我们继续了解android.graphics包中比较重要的绘图类。一、 android.graphics.Matrix有关图形的变换、缩放等相关操作常用的方法有:void reset() / 重置一个matrix对象。void set(Matrix src) /复制一个源矩阵,和本类的构造方法 Matrix(Matrix src) 一样boolean isIdentity() /返回这个矩阵是否定义(已经有意义)void setRotate(float degrees) /指定一个角度以0,0为坐标进行旋转void s
31、etRotate(float degrees, float px, float py) /指定一个角度以px,py为坐标进行旋转void setScale(float sx, float sy) / 缩放void setScale(float sx, float sy, float px, float py) /以坐标px,py进行缩放void setTranslate(float dx, float dy) /平移void setSkew (float kx, float ky, float px, float py) /以坐标px,py进行倾斜void setSkew (float kx, float ky) /倾斜
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