Android编程实现文字倒影效果的方法

本文实例讲述了Android编程实现文字倒影效果的方法。分享给大家供大家参考，具体如下：

我们所有的view都继承自View类，View类里有个方法叫ondraw(). 即，我们看到的界面都是画出来的，所以我们可以重写ondraw()方法。

既然知道了这点就好办了，还有个难点就是，我们的倒影也是画出来的，那我们从哪去取原始图片呢？熟悉View的童鞋都知道Cache这个东西，不错，就是通过Cache我们取到了原始图片。

放源码了。，感谢期待。这个只是个demo，并不完善哈，布局什么的还需要调整下，或者我什么时候有空再进行一次封装，就可以直接从布局文件中任意调整了。

布局文件中增加如下代码

<com.tc.reflect.ReflectTextView
    android:layout_marginTop="20dp"
    android:id="@+id/test_reflect" android:layout_width="fill_parent"
    android:layout_height="50dp" android:textSize="25dp"
    android:textColor="#ff0000" android:textStyle="bold" android:gravity="top|center_horizontal"
    android:text="不会飞翔的翅膀 XP.C" />
    <com.tc.reflect.ReflectTextView
    android:layout_marginTop="20dp"
    android:id="@+id/test_reflect" android:layout_width="fill_parent"
    android:layout_height="50dp" android:textSize="25dp"
    android:textColor="#a0a0a0" android:textStyle="italic" android:gravity="top|center_horizontal"
    android:text="titanchen2000@yahoo.com.cn" />

类代码如下：

/*
 * Copyright (C) 2011 TC Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions and limitations under the
 * License. This code is base on the Android TextView and was Created by titanchen2000@yahoo.com.cn
 *
 * @author TC
 */
package com.tc.reflect;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.util.AttributeSet;
import android.widget.TextView;
public class ReflectTextView extends TextView {
  public ReflectTextView(Context context) {
    super(context);
  }
  public ReflectTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
  }
  public ReflectTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
  @Override
  protected void onDraw(Canvas canvas) {
    //draw the text from layout()
    super.onDraw(canvas);
    int height = getHeight();
    int width = getWidth();
    //make the shadow reverse of Y
    Matrix matrix = new Matrix();
    matrix.preScale(1, -1);
    //make sure you can use the cache
    setDrawingCacheEnabled(true);
    //create bitmap from cache,this is the most important of this
    Bitmap originalImage = Bitmap.createBitmap(getDrawingCache());
    //create the shadow
    Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
        height / 3, width, height / 3, matrix, false);
    //draw the shadow
    canvas.drawBitmap(reflectionImage, 0, 8 * height / 12, null);
    //process shadow bitmap to make it shadow like
    Paint paint = new Paint();
    LinearGradient shader = new LinearGradient(0, 8 * height / 12, 0,
        height, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
    paint.setShader(shader);
    paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
    canvas.drawRect(0, 8 * height / 12, width, height, paint);
  }
}

更多关于Android相关内容感兴趣的读者可查看本站专题：《Android图形与图像处理技巧总结》、《Android开发入门与进阶教程》、《Android调试技巧与常见问题解决方法汇总》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结》

希望本文所述对大家Android程序设计有所帮助。