安卓判断滑动方向onTouchEvent

最新推荐文章于 2024-06-27 17:25:00 发布

原创最新推荐文章于 2024-06-27 17:25:00 发布 · 1.6k 阅读

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该博客详细介绍了如何在Android中通过onTouchEvent方法判断用户的滑动方向。通过记录ACTION_DOWN和ACTION_UP时的坐标，计算滑动的水平和垂直距离，根据距离大小判断是左右滑还是上下滑，并设置了相应的背景颜色提示。

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initview();
}

private void initview() {
textView = (TextView) findViewById(R.id.tv1);

}

float x_temp01 = 0.0f;
float y_temp01 = 0.0f;
float x_temp02 = 0.0f;
float y_temp02 = 0.0f;
private TextView textView;

@Override
public boolean onTouchEvent(MotionEvent event) {
// 获得当前坐标

switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
x_temp01 = event.getX();
y_temp01 = event.getY();

break;
case MotionEvent.ACTION_UP:
x_temp02 = event.getX();
y_temp02 = event.getY();
direction();

break;

}
return super.onTouchEvent(event);
}

private void direction() {
float h = x_temp02 - x_temp01;
float l = y_temp02 - y_temp01;

if (Math.abs(h) > Math.abs(l)) {
if (h > 0)// 向左
{
// 移动了x_temp01-x_temp02
textView.setText("向左滑动");
textView.setBackgroundColor(Color.BLUE);
} else {

// 移动了x_temp02-x_temp01
textView.setText("向右滑动");
textView.setBackgroundColor(Color.GREEN);
}

} else {
if (l > 0)// 向下
{

textView.setText("向下滑动");
textView.setBackgroundColor(Color.RED);
} else {

textView.setText("向上滑动");
textView.setBackgroundColor(Color.YELLOW);
}
}

// 比较x_temp01和x_temp02
// x_temp01>x_temp02 //向左
// x_temp01==x_temp02 //竖直方向或者没动
// x_temp01<x_temp02 //向右

}
}