开源SlidingMenu笔记(二)

来源：互联网发布：php ahp和jhp 编辑：程序博客网时间：2024/05/29 15:39

滑动菜单栏和滑动的效果都是在此类中实现。

[java] view plaincopy
package com.example.myslidingmenudemo08;  
  
import android.graphics.Canvas;  
import android.os.Bundle;  
import android.view.MenuItem;  
  
import com.jeremyfeinstein.slidingmenu.lib.SlidingMenu;  
import com.jeremyfeinstein.slidingmenu.lib.SlidingMenu.CanvasTransformer;  
import com.jeremyfeinstein.slidingmenu.lib.app.SlidingFragmentActivity;  
  
public class MainActivity extends SlidingFragmentActivity {  
    private CanvasTransformer mTransformer;  
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
  
        setTitle("Zoom");  
          
        initAnimation();  
          
        initSlidingMenu();  
          
        getActionBar().setDisplayHomeAsUpEnabled(true);  
    }  
  
    /** 
     * 初始化滑动菜单 
     */  
    private void initSlidingMenu(){  
        // 设置主界面视图  
        setContentView(R.layout.content_frame);  
        getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new SampleListFragment()).commit();  
                  
        // 设置滑动菜单视图  
        setBehindContentView(R.layout.menu_frame);  
        getSupportFragmentManager().beginTransaction().replace(R.id.menu_frame, new SampleListFragment()).commit();  
  
        // 设置滑动菜单的属性值  
        SlidingMenu sm = getSlidingMenu();        
        sm.setShadowWidthRes(R.dimen.shadow_width);  
        sm.setShadowDrawable(R.drawable.shadow);  
        sm.setBehindOffsetRes(R.dimen.slidingmenu_offset);  
        sm.setFadeDegree(0.35f);  
        sm.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);  
        sm.setBehindScrollScale(0.0f);  
        sm.setBehindCanvasTransformer(mTransformer);  
          
        setSlidingActionBarEnabled(true);  
    }  
  
    /** 
     * 初始化动画效果 
     */  
    private void initAnimation(){  
        mTransformer = new CanvasTransformer(){  
            @Override  
            public void transformCanvas(Canvas canvas, float percentOpen) {  
                float scale = (float) (percentOpen*0.25 + 0.75);  
                canvas.scale(scale, scale, canvas.getWidth()/2, canvas.getHeight()/2);                
            }  
              
        };  
    }  
      
    @Override  
    public boolean onOptionsItemSelected(MenuItem item) {  
        switch (item.getItemId()) {  
        case android.R.id.home:  
            toggle();  
            return true;          
        }  
        return super.onOptionsItemSelected(item);  
    }  
      
}  

大家可以先看一遍上面的这段代码，要想实现动画效果主要有三个步骤：

<1> 先定义一个CanvasTransformer接口对象，这个接口是在slidingmenu_library类库中封装好的，所以要想运行此项目还要导入slidingmenu_library类库

[java] view plaincopy
private CanvasTransformer mTransformer;  

<2> 然后再实例化此接口，重写接口中的方法：

[java] view plaincopy
mTransformer = new CanvasTransformer(){  
            @Override  
            public void transformCanvas(Canvas canvas, float percentOpen) {  
                float scale = (float) (percentOpen*0.25 + 0.75);  
                canvas.scale(scale, scale, canvas.getWidth()/2, canvas.getHeight()/2);                
            }  
              
        };  

我们可以看到在transformCanvas(Canvas canvas, float percentOpen)方法中，有两个参数：

① Canvas canvas：画布类；

② float percentOpen：滑动菜单栏打开时的百分比值。

<3> 最后在把实例化的接口对象赋给SlidingMenu类中的setBehindCanvasTransformer()方法：

[java] view plaincopy
sm.setBehindCanvasTransformer(mTransformer);  

这样，一个滑动菜单栏打开时的动画效果就配置好了

转自:http://blog.csdn.net/yangyu20121224/article/details/9262931

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