觸摸事件學習系列文章詳見:
《Android Touch事件學習系列匯總》
還是回到onTouchEvent方法傳遞的參數MotionEvent類,其對象有四個方法可以獲取當前手指在屏幕上的位置信息,但是一個是相對地址一個是絕對地址,以下具體看下區別。
一、Android Touch事件rawX,rawY與x,y的區別
MotionEvent有四個方法getRawX(), event.getRawY(), getX(),getY(), 為什麼同樣是x,y軸幹嘛非得用兩個變量呢?
先來看下效果圖:
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″brush:java;”>public class CustomTextView extends TextView {
private LogListener mLogListener;
public CustomTextView(Context context) {
super(context);
}
public CustomTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public void setLogListener(LogListener pListener) {
mLogListener = pListener;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_MOVE:
float rawX = event.getRawX();
float rawY = event.getRawY();
float x = event.getX();
float y = event.getY();
if (mLogListener != null) {
mLogListener.output(“rawX = ” + rawX
+ “\n rawY = ” + rawY
+ “\n x = ” + x
+ “\n Y = ” + y);
}
break;
}
return true;
}
/**
* 用於在Actvity中實時Touch位置輸出信息
*/
public interface LogListener {
public void output(String pOutput);
}
}
2. 在AndroidManifast.xml中配置佈局
3. Activity中加載視圖,控制顯示touch位置信息
public class TouchDemoActivity extends Activity { private TextView mOutput; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mOutput = (TextView) findViewById(R.id.output); mOutput.setText("rawX = 0 \n rawY = 0 \n x = 0 \n Y = 0"); CustomTextView customTextView = (CustomTextView) findViewById(R.id.custom_textview); customTextView.setLogListener(new CustomLogListener()); } /** * 用於獲取TouchEvent中位置信息 */ private class CustomLogListener implements LogListener { @Override public void output(String pOutput) { mOutput.setText( pOutput ); } } }
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