Toast的makeText()方法报错
帖上一代码,用Toast来简单处理回调机制.但是Toast的makeText()方法老报错:
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.Button;
import android.widget.Toast;
public class MyButton extends Button {
public MyButton(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
super.onKeyDown(keyCode, event);
//就是这里了
Toast toast=Toast.makeText(MyButton.this, "the callBack test", 5000);
toast.show();
return true;
}
}
报错信息：
The method makeText(Context, CharSequence, int) in the type Toast is not applicable for the arguments (MyButton, String, int)
------解决方案--------------------
public class MyButton extends Button {
private Context mContext;
public MyButton(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
}
Toast toast=Toast.makeText(mContext, "the callBack test", 5000);
toast.show();
------解决方案--------------------
第一个参数，使用 getContext() 或者 getApplicationContext()
第三个参数也不正确，应该是 Toast.makeText(getContext(), "the callBack test", Toast.LENGTH_LONG).show();