[AndroidUI]自定义view(二)：实现带说明的图片

参考链接：http://blog.csdn.net/lmj623565791/article/details/24300125

自定义view的步骤：

1.res/values/下新建一个attrs.xml，创建自定义的属性

属性类型可以取：string,color,demension,integer,enum,reference,float,boolean,fraction,flag

2.在布局文件中添加自定义的view，为自定义的属性赋值

自定义的属性属于不同的命名空间

3.为自定义的view重写方法，获取自定义的属性

1.attrs.xml

<?xml version="1.0" encoding="utf-8"?><resources>   <attr name="titleText" format="string" />      <attr name="titleTextSize" format="dimension" />      <attr name="titleTextColor" format="color" />      <attr name="image" format="reference" />      <attr name="imageScaleType">          <enum name="fillXY" value="0" />          <enum name="center" value="1" />      </attr>        <declare-styleable name="CustomImageView">          <attr name="titleText" />          <attr name="titleTextSize" />          <attr name="titleTextColor" />          <attr name="image" />          <attr name="imageScaleType" />      </declare-styleable>   </resources>

2.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"      xmlns:custom="http://schemas.android.com/apk/res/com.example.testview2"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:orientation="vertical">        <com.example.testview2.MyView2           android:layout_width="wrap_content"          android:layout_height="wrap_content"          android:layout_margin="10dp"          android:padding="10dp"          custom:image="@drawable/ic_launcher"          custom:imageScaleType="center"          custom:titleText="hello andorid ! "          custom:titleTextColor="#ff0000"          custom:titleTextSize="30sp"/>        <com.example.testview2.MyView2           android:layout_width="100dp"          android:layout_height="wrap_content"          android:layout_margin="10dp"          android:padding="10dp"          custom:image="@drawable/ic_launcher"          custom:imageScaleType="center"          custom:titleText="helloworldwelcome"          custom:titleTextColor="#00ff00"          custom:titleTextSize="20sp"/>              <com.example.testview2.MyView2           android:layout_width="wrap_content"          android:layout_height="wrap_content"          android:layout_margin="10dp"          android:padding="10dp"          custom:image="@drawable/a"          custom:imageScaleType="center"          custom:titleText="妹子~"          custom:titleTextColor="#ff0000"          custom:titleTextSize="12sp"/>          </LinearLayout> 

3.

package com.example.testview2;import java.util.HashSet;import java.util.Random;import java.util.Set;import android.R.integer;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Paint.Style;import android.graphics.Rect;import android.text.TextPaint;import android.text.TextUtils;import android.util.AttributeSet;import android.view.View;import android.view.View.MeasureSpec;import android.view.View.OnClickListener;public class MyView2 extends View {private String titleText;private int titleTextColor;private float titleTextSize;private Bitmap image;private int imageScaleType;private static final int IMAGE_SCALE_FITXY = 0;private static final int IMAGE_SCALE_CENTER = 1;private Rect imageRect;//图片的绘制范围private Rect textRect;//绘制时控制文本绘制的范围private Paint paint;public MyView2(Context context) {super(context);}//默认的布局文件调用的是两个参数的构造方法public MyView2(Context context, AttributeSet attrs) {this(context, attrs, 0);}public MyView2(Context context, AttributeSet attrs, int defStyle){super(context, attrs, defStyle);TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomImageView, defStyle, 0);titleText = typedArray.getString(R.styleable.CustomImageView_titleText);titleTextColor = typedArray.getColor(R.styleable.CustomImageView_titleTextColor, Color.BLACK);titleTextSize = typedArray.getDimension(R.styleable.CustomImageView_titleTextSize, 80);image = BitmapFactory.decodeResource(getResources(), typedArray.getResourceId(R.styleable.CustomImageView_image, 0));imageScaleType = typedArray.getInt(R.styleable.CustomImageView_imageScaleType, 0);imageRect = new Rect();textRect = new Rect();paint = new Paint();paint.setTextSize(titleTextSize);paint.getTextBounds(titleText, 0, titleText.length(), textRect);//文本绘制范围typedArray.recycle();}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {int widthMode = MeasureSpec.getMode(widthMeasureSpec);      int widthSize = MeasureSpec.getSize(widthMeasureSpec);      int heightMode = MeasureSpec.getMode(heightMeasureSpec);      int heightSize = MeasureSpec.getSize(heightMeasureSpec);      int width;      int height;        if(widthMode == MeasureSpec.EXACTLY)//match_parent, accurate    {    width = widthSize;    }    else    {    // 由图片决定的宽          int desireByImg = getPaddingLeft() + getPaddingRight() + image.getWidth();          // 由字体决定的宽          int desireByTitle = getPaddingLeft() + getPaddingRight() + textRect.width();            width = Math.max(desireByImg, desireByTitle);    }        if(heightMode == MeasureSpec.EXACTLY)    {    height = heightSize;    }    else    {    height = getPaddingTop() + getPaddingBottom() + image.getHeight() + textRect.height();    }        //确定整个控件的宽高    setMeasuredDimension(width, height);}@Overrideprotected void onDraw(Canvas canvas) {//绘制边框paint.setStrokeWidth(4);  paint.setStyle(Paint.Style.STROKE);  paint.setColor(Color.CYAN); canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), paint);paint.setColor(titleTextColor);  paint.setStyle(Style.FILL);//当前设置的宽度小于字体需要的宽度，将字体改为xxx...        if (textRect.width() > getMeasuredWidth())          {              TextPaint paint = new TextPaint(this.paint);              String msg = TextUtils.ellipsize(titleText, paint, getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),                      TextUtils.TruncateAt.END).toString();              canvas.drawText(msg, getPaddingLeft(), getMeasuredHeight() - getPaddingBottom(), this.paint);            }         else        {        //居中,以text的左下角为原点        canvas.drawText(titleText, getMeasuredWidth() / 2 - textRect.width() / 2, getMeasuredHeight() - getPaddingBottom(), paint);        }if(imageScaleType == IMAGE_SCALE_FITXY){imageRect.left = getPaddingLeft();  imageRect.right = getMeasuredWidth() - getPaddingRight();  imageRect.top = getPaddingTop();  imageRect.bottom = getMeasuredHeight() - getPaddingBottom() - textRect.height();}else{imageRect.left = getMeasuredWidth() / 2 - image.getWidth() / 2;imageRect.right = getMeasuredWidth() / 2 + image.getWidth() / 2;imageRect.top = getMeasuredHeight() - textRect.height() - image.getHeight() - getPaddingBottom();imageRect.bottom = getMeasuredHeight() - textRect.height() - getPaddingBottom();}canvas.drawBitmap(image, null, imageRect, paint);}}

效果图：