Android實現Google Play上的文本伸縮功能示例

 經常上google play下載軟件，看到它的伸縮式的軟件介紹很感興趣。功能截圖如下：

點擊文本會下拉更多詳細介紹，實現這一功能很簡單，廢話不多說，直接上代碼

private boolean isExpanded = false; 
    private int lastHeight = 0; 
 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_expand_in_context); 
 
        final ViewGroup expandableContainer = (ViewGroup) findViewById(R.id.expandable_container); 
 
        findViewById(R.id.expandable_text).setOnClickListener( 
                new View.OnClickListener() { 
 
                    @Override 
                    public void onClick(View v) { 
                        if (isExpanded) { 
                            ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) expandableContainer 
                                    .getLayoutParams(); 
 
                            params.height = lastHeight; 
 
                            expandableContainer.setLayoutParams(params); 
                            expandableContainer.invalidate(); 
                        } else { 
                            lastHeight = expandableContainer.getHeight(); 
 
                            ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) expandableContainer 
                                    .getLayoutParams(); 
 
                            params.height = ViewGroup.LayoutParams.WRAP_CONTENT; 
 
                            expandableContainer.setLayoutParams(params); 
                            expandableContainer.invalidate(); 
                        } 
 
                        isExpanded = !isExpanded; 
 
                    } 
                }); 
 
    } 

布局只需要這樣：

<FrameLayout 
            android:id="@+id/expandable_container" 
            android:layout_width="wrap_content" 
            android:layout_height="200dp" 
            android:layout_below="@+id/above" 
            android:layout_margin="15dp" 
             > 
 
            <TextView 
                android:id="@+id/expandable_text" 
                android:layout_width="match_parent" 
                android:layout_height="match_parent" 
                android:ellipsize="end" 
                android:text="@string/loremipsum"  
                android:clickable="true"/> 
        </FrameLayout> 

父布局限定了可限示的高度，可以使文本不用一次性全部顯示，為屏幕節省空間。等用戶點擊查時才一次性顯示全部給用戶，再一次點擊則隱藏掉。。原理很簡單。

轉自：http://www.cnblogs.com/TerryBlog/archive/2013/03/12/2956165.html