仿微信图片和文字颜色改变

1、自定义属性文件

<?xml version="1.0" encoding="utf-8"?>
<resources>

<attr name="icon" format="reference"></attr>
<attr name="color" format="color"></attr>
<attr name="text" format="string"></attr>
<attr name="text_size" format="dimension"></attr>

<declare-styleable name="ChangeColorIconWithText">
<attr name="icon"></attr>
<attr name="color"></attr>
<attr name="text"></attr>
<attr name="text_size"></attr>
</declare-styleable>

</resources>

2、自定义VIew
package com.imooc.weixin6_0;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Looper;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;

public class ChangeColorIconWithText extends View {

private int mColor = 0xFF45C01A;
private Bitmap mIconBitmap;
private String mText = "微信";
private int mTextSize = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 12, getResources().getDisplayMetrics());

private Canvas mCanvas;
private Bitmap mBitmap;
private Paint mPaint;

private float mAlpha;

private Rect mIconRect;
private Rect mTextBound;
private Paint mTextPaint;

public ChangeColorIconWithText(Context context) {
this(context, null);
}

public ChangeColorIconWithText(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

/**
* 获取自定义属性的值
*
* @param context
* @param attrs
* @param defStyleAttr
*/
public ChangeColorIconWithText(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);

TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.ChangeColorIconWithText);

int n = a.getIndexCount();

for (int i = 0; i < n; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.ChangeColorIconWithText_icon:
BitmapDrawable drawable = (BitmapDrawable) a.getDrawable(attr);
mIconBitmap = drawable.getBitmap();
break;
case R.styleable.ChangeColorIconWithText_color:
mColor = a.getColor(attr, 0xFF45C01A);
break;
case R.styleable.ChangeColorIconWithText_text:
mText = a.getString(attr);
break;
case R.styleable.ChangeColorIconWithText_text_size:
mTextSize = (int) a.getDimension(attr, TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12,
getResources().getDisplayMetrics()));
break;
}

}

a.recycle();

mTextBound = new Rect();
mTextPaint = new Paint();
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0Xff555555);
mTextPaint.getTextBounds(mText, 0, mText.length(), mTextBound);

}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int iconWidth = Math.min(getMeasuredWidth() - getPaddingLeft()
- getPaddingRight(), getMeasuredHeight() - getPaddingTop()
- getPaddingBottom() - mTextBound.height());

int left = getMeasuredWidth() / 2 - iconWidth / 2;
int top = getMeasuredHeight() / 2 - (mTextBound.height() + iconWidth)
/ 2;
mIconRect = new Rect(left, top, left + iconWidth, top + iconWidth);
}

@Override
protected void onDraw(Canvas canvas) {
try {
canvas.drawBitmap(mIconBitmap, null, mIconRect, null);

int alpha = (int) Math.ceil(255 * mAlpha);

// 内存去准备mBitmap , setAlpha , 纯色 ，xfermode ， 图标
setupTargetBitmap(alpha);
// 1、绘制原文本 ； 2、绘制变色的文本
drawSourceText(canvas, alpha);
drawTargetText(canvas, alpha);

canvas.drawBitmap(mBitmap, 0, 0, null);

} catch (Exception e) {
e.printStackTrace();
}

}

/**
* 绘制变色的文本
*
* @param canvas
* @param alpha
*/
private void drawTargetText(Canvas canvas, int alpha) {
mTextPaint.setColor(mColor);
mTextPaint.setAlpha(alpha);
int x = getMeasuredWidth() / 2 - mTextBound.width() / 2;
int y = mIconRect.bottom + mTextBound.height();
canvas.drawText(mText, x, y, mTextPaint);

}

/**
* 绘制原文本
*
* @param canvas
* @param alpha
*/
private void drawSourceText(Canvas canvas, int alpha) {
mTextPaint.setColor(0xff333333);
mTextPaint.setAlpha(255 - alpha);
int x = getMeasuredWidth() / 2 - mTextBound.width() / 2;
int y = mIconRect.bottom + mTextBound.height();
canvas.drawText(mText, x, y, mTextPaint);

}

/**
* 在内存中绘制可变色的Icon
*/
private void setupTargetBitmap(int alpha) {
mBitmap = Bitmap.createBitmap(getMeasuredWidth(), getMeasuredHeight(),
Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPaint = new Paint();
mPaint.setColor(mColor);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setAlpha(alpha);
//绘制透明度变化的矩形
mCanvas.drawRect(mIconRect, mPaint);
//设置两个图形相交时的模式
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAlpha(255);
//绘制icon图片
mCanvas.drawBitmap(mIconBitmap, null, mIconRect, mPaint);
}

private static final String INSTANCE_STATUS = "instance_status";
private static final String STATUS_ALPHA = "status_alpha";

@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(INSTANCE_STATUS, super.onSaveInstanceState());
bundle.putFloat(STATUS_ALPHA, mAlpha);
return bundle;
}

@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
mAlpha = bundle.getFloat(STATUS_ALPHA);
super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATUS));
return;
}
super.onRestoreInstanceState(state);
}

public void setIconAlpha(float alpha) {
this.mAlpha = alpha;
invalidateView();
}

/**
* 重绘
*/
private void invalidateView() {
if (Looper.getMainLooper() == Looper.myLooper()) {
invalidate();
} else {
postInvalidate();
}
}

}


3、布局文件
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:hyman="http://schemas.android.com/apk/res/com.imooc.weixin6_0"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<android.support.v4.view.ViewPager
android:id="@+id/id_viewpager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" >
</android.support.v4.view.ViewPager>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="60dp"
android:background="@drawable/tab_bg"
android:orientation="horizontal" >

<com.imooc.weixin6_0.ChangeColorIconWithText
android:id="@+id/id_indicator_one"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
hyman:icon="@drawable/ic_menu_start_conversation"
hyman:text="@string/app_name"
hyman:text_size="12sp"
hyman:color="#ff45c01a" />

<com.imooc.weixin6_0.ChangeColorIconWithText
android:id="@+id/id_indicator_two"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
hyman:icon="@drawable/ic_menu_friendslist"
hyman:text="@string/tab_contact"
hyman:text_size="12sp"
hyman:color="#ff45c01a" />

<com.imooc.weixin6_0.ChangeColorIconWithText
android:id="@+id/id_indicator_three"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
hyman:icon="@drawable/ic_menu_emoticons"
hyman:text="@string/tab_found"
hyman:text_size="12sp"
hyman:color="#ff45c01a" />

<com.imooc.weixin6_0.ChangeColorIconWithText
android:id="@+id/id_indicator_four"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:padding="5dp"
hyman:icon="@drawable/ic_menu_allfriends"
hyman:text="@string/tab_me"
hyman:text_size="12sp"
hyman:color="#ff45c01a" />
</LinearLayout>

</LinearLayout>

来自：http://www.eoeandroid.com/thread-562437-1-1.html