Bitmap 相关2：Bitmap.createBitmap() 使用

 Bitmap 创建

 

 

 

 

[代码 步骤]

1. 创建Bitmaop 且指向icon.png

Bitmap ori = BitmapFactory.decodeResource(this.getResources(), R.drawable.icon);

 

 

2. 创建布局文件 有2个ImageView 一个供原图显示 一个供切割后显示

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/layout"
    >
<ImageView  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/image1"
    android:layout_gravity="center_horizontal"
    />
<ImageView  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/image2"
    android:layout_gravity="center"
    />
</LinearLayout>

 

 

3. 初始化变量

lLauout = (LinearLayout)findViewById(R.id.layout);
        
iv1 = (ImageView)findViewById(R.id.image1);
iv2 = (ImageView)findViewById(R.id.image2);

 

4. 得到原图的宽度与高度 供后面使用

width = ori.getWidth();
height = ori.getHeight();

 

5.  定义变量 标志切割位置 并初始化之

int startX,startY,lengthX,lengthY;

 

startX = 0;
startY = 0;

lengthX = width;
lengthY = height;

 

 

 6. 如何选取图片位置

 

public boolean onKeyDown(int keyCode, KeyEvent msg){
    	
    	switch(keyCode){
    	case KeyEvent.KEYCODE_DPAD_LEFT:
    		updateLeft();
    		break;
    		
    	case KeyEvent.KEYCODE_DPAD_RIGHT:
    		updateRight();
    		break;
    	case KeyEvent.KEYCODE_DPAD_UP:
    		updateUp();
    		break;
    	case KeyEvent.KEYCODE_DPAD_DOWN:
    		updateDown();
    		break;
    	case KeyEvent.KEYCODE_DPAD_CENTER:
    		showResult();
    		break;
    	}
    	
    	return false;
    }

 

 

7.  还需要判断移动是否合理

以下几种情况不合理：

1. 当图形左边 比 图形最大宽度 还大
2. 当图形上边 比 图形最大高度 还大
3. 图形宽度 或 高度 小于 0

 

public boolean isUpdateOK(){
    	if((startX > lengthX)||(startY > lengthY)||(lengthX > 0)||(lengthY > 0)){
    		return false;
    	}
    	else {
    		return true;
    	}
    }

 

 

8. 具体移动方法：

public void updateLeft(){
    	startX += step;
    	lengthX = width-startX;
        lengthY = height-startY;
        
        if(isUpdateOK()){
        	target1.recycle();
        	
        	target1 = Bitmap.createBitmap(ori,startX, startY, lengthX, lengthY);
        	
        	iv2.setImageBitmap(target1);
        	
        	setContentView(lLauout);
        }
    }
    public void updateUp(){
    	startY += step;
    	lengthX = width-startX;
        lengthY = height-startY;
        
        if(isUpdateOK()){
        	target1.recycle();
        	
        	target1 = Bitmap.createBitmap(ori,startX, startY, lengthX, lengthY);
        	
        	iv2.setImageBitmap(target1);
        	
        	setContentView(lLauout);
        }
    }
    public void updateRight(){
        lengthX -= step;
        
        if(isUpdateOK()){
        	target1.recycle();
        	
        	target1 = Bitmap.createBitmap(ori,startX, startY, lengthX, lengthY);
        	
        	iv2.setImageBitmap(target1);
        	
        	setContentView(lLauout);
        }
    }
    public void updateDown(){
        lengthY -= step;
        
        if(isUpdateOK()){
        	target1.recycle();
        	
        	target1 = Bitmap.createBitmap(ori,startX, startY, lengthX, lengthY);
        	
        	iv2.setImageBitmap(target1);
        	
        	setContentView(lLauout);
        }
    }
    
    
    public void showResult(){
    	AlertDialog.Builder ab = new AlertDialog.Builder(this);
    	AlertDialog aDialog;
    	
    	ab.setMessage("startX:"+startX+"\n"+"startY:"+startY+"\n"+"lengthX:"+lengthX+"\n"+"lengthY:"+lengthY).setTitle("show result").show();;
    	aDialog = ab.create();

    	aDialog.show();
    	
    }

 

 

 

9. emulator 运行情况：