android 仿QQ好友动态 title滑动渐变

   最近QQ更新了qq空间消息列表。天天动听也使用了那效果。而且越来越多的android应用都在使用，咱们不能落后啊！

   得紧跟时代的步伐，不然就out了。 看起来不错分享下咯！

   首先贴一下效果图，因为gif动态图片不懂怎么搞。下次一定改进。

贴下代码先：

自定义了滑动时背景颜色渐变

1. package com.seven.fadingdemo;
2. 
   
3. 
   
4. import com.seven.fadingactionbardemo.R;
5. 
   
6. 
   
7. import android.annotation.SuppressLint;
8. import android.content.Context;
9. import android.graphics.drawable.Drawable;
10. import android.util.AttributeSet;
11. import android.view.MotionEvent;
12. import android.widget.ImageView;
13. import android.widget.LinearLayout;
14. 
    
15. 
    
16. /**
17.  * 定义的控件布局
18.  * 
19.  * @author seven2729
20.  */
21. public class FadingScrollView extends LinearLayout {
22. 
    
23. 
    
24. private LinearLayout mActionBar;
25. 
    
26. 
    
27. private Drawable mBgDrawable;
28. 
    
29. 
    
30. private ImageView fadingBar;// title渐变的控件
31. 
    
32. 
    
33. private int fadingHeight; // 可隐藏的控件高度
34. private int oldY;
35. private int fadingOffset;
36. 
    
37. 
    
38. public static final int ALPHA_START = 20;
39. public static final int ALPHA_END = 255;
40. 
    
41. 
    
42. public FadingScrollView(Context context) {
43. this(context, null);
44. }
45. 
    
46. 
    
47. public FadingScrollView(Context context, AttributeSet attrs) {
48. this(context, attrs, 0);
49. }
50. 
    
51. 
    
52. @SuppressLint("NewApi")
53. public FadingScrollView(Context context, AttributeSet attrs,
54. int defStyleAttr) {
55. super(context, attrs, defStyleAttr);
56. 
    
57. 
    
58. setOrientation(VERTICAL);
59. }
60. 
    
61. 
    
62. @Override
63. protected void onFinishInflate() {
64. super.onFinishInflate();
65. 
    
66. 
    
67. fadingBar = (ImageView) findViewById(R.id.fading_bar);
68. }
69. 
    
70. 
    
71. @Override
72. protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
73. super.onMeasure(widthMeasureSpec, heightMeasureSpec);
74. fadingHeight = fadingBar.getMeasuredHeight() - fadingOffset;// title渐变的控件距离
75. }
76. 
    
77. 
    
78. @SuppressLint("ClickableViewAccessibility")
79. @Override
80. public boolean onTouchEvent(MotionEvent ev) {
81. 
    
82. 
    
83. switch (ev.getAction()) {
84. case MotionEvent.ACTION_DOWN:
85. oldY = (int) ev.getY();
86. break;
87. case MotionEvent.ACTION_MOVE:
88. int scrollY = getScrollY();
89. int y = (int) ev.getY();
90. int deltaY = y - oldY;
91. 
    
92. 
    
93. int willScrollY = scrollY - deltaY;
94. 
    
95. 
    
96. if (willScrollY > fadingHeight) 
97. {// 不做操作颜色保持不变
98. // willScrollY = fadingHeight;
99. }
100. else 
101. {// 颜色渐变
102. updateActionBarAlpha(willScrollY * (ALPHA_END - ALPHA_START)
103. / fadingHeight + ALPHA_START);
104. }
105. 
     
106. 
     
107. if (willScrollY < 0) {
108. willScrollY = 0;
109. }
110. 
     
111. 
     
112. scrollTo(0, willScrollY);
113. oldY = y;
114. 
     
115. 
     
116. break;
117. case MotionEvent.ACTION_UP:
118. break;
119. }
120. 
     
121. 
     
122. return true;
123. }
124. 
     
125. 
     
126. public void bindingActionBar(LinearLayout actionBar) {
127. mActionBar = actionBar;
128. }
129. 
     
130. 
     
131. @SuppressWarnings("deprecation")
132. public void setActionBarBgDrawable(Drawable bgDrawable) {
133. if (mActionBar == null) {
134. try {
135. throw new Exception(
136. "Please try to binding the actionBar before set it's background.");
137. } catch (Exception e) {
138. e.printStackTrace();
139. }
140. }
141. mBgDrawable = bgDrawable;
142. mBgDrawable.setAlpha(ALPHA_START);
143. mActionBar.setBackgroundDrawable(mBgDrawable);
144. }
145. 
     
146. 
     
147. @SuppressWarnings("deprecation")
148. public void setActionBarAlpha(int alpha) throws Exception {
149. if (mActionBar == null || mBgDrawable == null) {
150. throw new Exception(
151. "acitonBar is not binding or bgDrawable is not set.");
152. }
153. mBgDrawable.setAlpha(alpha);
154. mActionBar.setBackgroundDrawable(mBgDrawable);
155. }
156. 
     
157. 
     
158. void updateActionBarAlpha(int alpha) {
159. try {
160. setActionBarAlpha(alpha);
161. } catch (Exception e) {
162. e.printStackTrace();
163. }
164. }
165. 
     
166. 
     
167. public void setFadingOffset(int height) {
168. fadingOffset = height;
169. }
170. }

然后就是代码的使用了，根据自己的需要设置大小或者颜色。

1. package com.seven.fadingdemo;
2. 
   
3. 
   
4. import com.seven.fadingactionbardemo.R;
5. 
   
6. 
   
7. import android.annotation.SuppressLint;
8. import android.app.Activity;
9. import android.graphics.drawable.ColorDrawable;
10. import android.os.Bundle;
11. import android.widget.LinearLayout;
12. 
    
13. 
    
14. /**
15.  * 主页展示页面
16.  * 
17.  * @author seven2729
18.  */
19. public class MainActivity extends Activity {
20. private LinearLayout mLayout;
21. private FadingScrollView fadingScrollView;// 自定义滑动布局
22. 
    
23. 
    
24. @Override
25. protected void onCreate(Bundle savedInstanceState) {
26. super.onCreate(savedInstanceState);
27. // requestWindowFeature(Window.FEATURE_NO_TITLE);
28. setContentView(R.layout.activity_main);
29. 
    
30. 
    
31. fadingScrollView = (FadingScrollView) findViewById(R.id.root);
32. initLinearLayout();
33. }
34. 
    
35. 
    
36. /**
37. * 布局初始化
38. */
39. @SuppressLint({ "Recycle", "InlinedApi" })
40. void initLinearLayout() {
41. //初始化fadingScrollView的一些信息
42. mLayout = (LinearLayout) findViewById(R.id.lyout_title);
43. ColorDrawable bgDrawable = new ColorDrawable(getResources().getColor(
44. R.color.color_blue));
45. fadingScrollView.bindingActionBar(mLayout);// 设置渐变布局
46. fadingScrollView.setActionBarBgDrawable(bgDrawable);// 设置渐变颜色
47. }
48. 
    
49. }

颜色值的代码：

3.     #FFFFFF
4.     #000000
5.     #00000000
6.     #50BDFB
7.     

因为最近有在研究，所以找点资料自己修改了。改成自己需要的

如有需要可以  下载源码

如源码有偏差请根据博文修改！

欢迎转载，转载请注明出处：http://blog.csdn.net/seven2729/article/details/48372851