Android仿微信底部按鈕滑動(dòng)變色，這里只針對使用Fragment為Tab頁的滑動(dòng)操作，進(jìn)行簡單的變色講解。
創(chuàng)新互聯(lián)公司專注于赫章網(wǎng)站建設(shè)服務(wù)及定制，我們擁有豐富的企業(yè)做網(wǎng)站經(jīng)驗(yàn)。 熱誠為您提供赫章營銷型網(wǎng)站建設(shè)，赫章網(wǎng)站制作、赫章網(wǎng)頁設(shè)計(jì)、赫章網(wǎng)站官網(wǎng)定制、成都小程序開發(fā)服務(wù)，打造赫章網(wǎng)絡(luò)公司原創(chuàng)品牌,更為您提供赫章網(wǎng)站排名全網(wǎng)營銷落地服務(wù)。
首先說下OnPageChangeListener這個(gè)監(jiān)聽
//這個(gè)監(jiān)聽有三個(gè)方法 public abstract void onPageScrollStateChanged (int state) public abstract void onPageScrolled (int position, float positionOffset, int positionOffsetPixels) public abstract void onPageSelected (int position) //第一個(gè)方法onPageScrollStateChanged 中的參數(shù)state，有三個(gè)可取的值 public static final int SCROLL_STATE_DRAGGING Constant Value: 1 (0x00000001) //手指按在ViewPager上滑動(dòng)時(shí) public static final int SCROLL_STATE_IDLE Constant Value: 0 (0x00000000) //手指松開后，ViewPager自動(dòng)滑動(dòng)期間 public static final int SCROLL_STATE_SETTLING Constant Value: 2 (0x00000002) //ViewPager進(jìn)入了某個(gè)Page //如果在onPageScrollStateChanged 中輸出state的值，你會(huì)發(fā)現(xiàn)每次都是按順序打印出“1---2---0” //第二個(gè)方法onPageScrolled的三個(gè)參數(shù) position：//滑動(dòng)時(shí)，屏幕左側(cè)顯示的第一個(gè)page positionOffset：//滑動(dòng)比例，值的范圍為[0, 1)，手指往左滑動(dòng)，該值遞增，反之遞減 positionOffsetPixels：//滑動(dòng)距離，和屏幕有關(guān)，手指往左滑動(dòng)，該值遞增，反之遞減 //我們經(jīng)常需要檢查viewpager的滑動(dòng)方向并作出一些操作，這時(shí)你只需要通過position和positionOffset兩個(gè)值即可實(shí)現(xiàn)該功能。 //比如實(shí)現(xiàn)微信底部圖標(biāo)顏色漸變 向左滑動(dòng)時(shí) ChangeColorIconWithTextView left = mTabIndicator.get(position); //左側(cè)顯示的第一個(gè)page頁面上底部圖標(biāo)和文字的初始化 ChangeColorIconWithTextView right = mTabIndicator.get(position + 1); //右側(cè)顯示的Page底部圖標(biāo)和文字的初始化 left.setIconAlpha(1 - positionOffset); //設(shè)置圖標(biāo)的透明度 此時(shí)positionOffset值遞增 左側(cè)圖標(biāo)的顏色變淺 right.setIconAlpha(positionOffset); //右側(cè)圖標(biāo)的顏色逐漸變深 //第三個(gè)方法onPageSelected的三個(gè)參數(shù) position：//當(dāng)前選擇的page序號 //該方法被調(diào)用的時(shí)間比較特別，在上面的第一個(gè)方法中的“1---2----0”中的2執(zhí)行之后，onPageSelected就執(zhí)行，然后執(zhí)行“1---2----0”中的0。就是手指松開屏幕之后，onPageSelected被執(zhí)行。
上面提到了ChangeColorIconWithTextView 主要類
重慶分公司
重慶分公司
package com.mhealth.nursestation.app.pda.business.login.base.ui.fragmentutil;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
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;
import com.mhealth.nursestation.app.pda.R;
/**
* 此類用于修改顏色漸變
*/
public class ChangeColorIconWithTextView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mPaint;
/**
* 顏色
*/
private int mColor = 0XFF07B7C4;
/**
* 透明度 0.0-1.0 初始化必須是0 不是0就廢了
*/
private float mAlpha = 0f;
/**
* 圖標(biāo)
*/
private Bitmap mIconBitmap;
/**
* 限制繪制icon的范圍
*/
private Rect mIconRect;
/**
* icon底部文本
*/
private String mText = "微信";
private int mTextSize = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 10, getResources().getDisplayMetrics());
private Paint mTextPaint;
private Rect mTextBound = new Rect();
public ChangeColorIconWithTextView(Context context) {
super(context);
}
/**
* 初始化自定義屬性值
*
* @param context
* @param attrs
*/
public ChangeColorIconWithTextView(Context context, AttributeSet attrs) {
super(context, attrs);
// 獲取設(shè)置的圖標(biāo)
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.ChangeColorIconView);
int n = a.getIndexCount();
for (int i = 0; i < n; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.ChangeColorIconView_icon:
BitmapDrawable drawable = (BitmapDrawable) a.getDrawable(attr);
mIconBitmap = drawable.getBitmap();
break;
case R.styleable.ChangeColorIconView_color:
mColor = a.getColor(attr, 0x07B7C4);
break;
case R.styleable.ChangeColorIconView_text:
mText = a.getString(attr);
break;
case R.styleable.ChangeColorIconView_text_size:
mTextSize = (int) a.getDimension(attr, TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_SP, 10,
getResources().getDisplayMetrics()));
break;
}
}
a.recycle();
mTextPaint = new Paint();
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0xff07B7C4);
mTextPaint.setAntiAlias(true);
// 得到text繪制范圍
mTextPaint.getTextBounds(mText, 0, mText.length(), mTextBound);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// 得到繪制icon的寬
int bitmapWidth = Math.min(getMeasuredWidth() - getPaddingLeft()
- getPaddingRight(), getMeasuredHeight() - getPaddingTop()
- getPaddingBottom() - mTextBound.height());
int left = getMeasuredWidth() / 2 - bitmapWidth / 2;
int top = (getMeasuredHeight() - mTextBound.height()) / 2 - bitmapWidth
/ 2;
// 得到繪制icon的寬
mIconRect = new Rect(left, top, left + bitmapWidth, top + bitmapWidth);
}
@Override
protected void onDraw(Canvas canvas) {
int alpha = (int) Math.ceil((255 * mAlpha));
canvas.drawBitmap(mIconBitmap, null, mIconRect, null);
setupTargetBitmap(alpha);
drawSourceText(canvas, alpha);
drawTargetText(canvas, alpha);
canvas.drawBitmap(mBitmap, 0, 0, null);
}
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);
mCanvas.drawRect(mIconRect, mPaint);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAlpha(255);
mCanvas.drawBitmap(mIconBitmap, null, mIconRect, mPaint);
}
/**
* 透明度 255
*
* @param canvas
* @param alpha
*/
private void drawSourceText(Canvas canvas, int alpha) {
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0x00333333);
mTextPaint.setAlpha(255 - alpha);
canvas.drawText(mText, mIconRect.left + mIconRect.width() / 2
- mTextBound.width() / 2,
mIconRect.bottom + mTextBound.height(), mTextPaint);
}
private void drawTargetText(Canvas canvas, int alpha) {
mTextPaint.setColor(mColor);
mTextPaint.setAlpha(alpha);
canvas.drawText(mText, mIconRect.left + mIconRect.width() / 2
- mTextBound.width() / 2,
mIconRect.bottom + mTextBound.height(), mTextPaint);
}
public void setIconAlpha(float alpha) {
this.mAlpha = alpha;
invalidateView();
}
private void invalidateView() {
if (Looper.getMainLooper() == Looper.myLooper()) {
invalidate();
} else {
postInvalidate();
}
}
public void setIconColor(int color) {
mColor = color;
}
public void setIcon(int resId) {
this.mIconBitmap = BitmapFactory.decodeResource(getResources(), resId);
if (mIconRect != null)
invalidateView();
}
public void setIcon(Bitmap iconBitmap) {
this.mIconBitmap = iconBitmap;
if (mIconRect != null)
invalidateView();
}
private static final String INSTANCE_STATE = "instance_state";
private static final String STATE_ALPHA = "state_alpha";
@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(INSTANCE_STATE, super.onSaveInstanceState());
bundle.putFloat(STATE_ALPHA, mAlpha);
return bundle;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
mAlpha = bundle.getFloat(STATE_ALPHA);
super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATE));
} else {
super.onRestoreInstanceState(state);
}
}
}
在Activity里面實(shí)現(xiàn)監(jiān)聽操作
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if (positionOffset > 0) {
ChangeColorIconWithTextView left = mTabIndicator.get(position);
ChangeColorIconWithTextView right = mTabIndicator.get(position + 1);
left.setIconAlpha(1 - positionOffset);
right.setIconAlpha(positionOffset);
}
}
定義一個(gè)集合，將所有變色控件裝載進(jìn)去
private ListmTabIndicator = new ArrayList (); private void initTabIndicator() { ChangeColorIconWithTextView one = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_one); ChangeColorIconWithTextView two = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_two); ChangeColorIconWithTextView three = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_three); ChangeColorIconWithTextView four = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_four); mTabIndicator.add(one); mTabIndicator.add(two); mTabIndicator.add(three); mTabIndicator.add(four); one.setOnClickListener(this); two.setOnClickListener(this); three.setOnClickListener(this); four.setOnClickListener(this); one.setIconAlpha(1.0f); }
點(diǎn)擊監(jiān)聽
@Override
public void onClick(View v) {
resetOtherTabs();
switch (v.getId()) {
case R.id.id_indicator_one:
mTabIndicator.get(0).setIconAlpha(1.0f);
mViewPager.setCurrentItem(0, false);
break;
case R.id.id_indicator_two:
mTabIndicator.get(1).setIconAlpha(1.0f);
mViewPager.setCurrentItem(1, false);
break;
case R.id.id_indicator_three:
mTabIndicator.get(2).setIconAlpha(1.0f);
mViewPager.setCurrentItem(2, false);
mAppContext.has_new_talk = false;
break;
case R.id.id_indicator_four:
mTabIndicator.get(3).setIconAlpha(1.0f);
mViewPager.setCurrentItem(3, false);
break;
}
}
以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持創(chuàng)新互聯(lián)。
