Question

android添加按钮出错，Button bn = new Button(this);报错

public class MainActivity extends Activity
{
GridLayout gridLayout;
Button bn_add;
int location = 0;
String[] chars = new String[]
{
"1", "2", "3",
"4", "5", "6",
"7", "8"
};

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

gridLayout = (GridLayout) findViewById(R.id.root);
bn_add = (Button) findViewById(R.id.add);

bn_add.setOnClickListener(new OnClickListener()
{

@Override
public void onClick(View source) {
Button bn = new Button(this);//这句报错

location++;
bn.setText(chars[location-1]);
bn.setPadding(10, 5, 0, 0);

GridLayout.Spec rowSpec = GridLayout.spec(location / 3 );
GridLayout.Spec columnSpec = GridLayout.spec(location % 3);

GridLayout.LayoutParams params = new GridLayout.LayoutParams(rowSpec, columnSpec);
gridLayout.addView(bn_add, params);
}
});
}
}

Answer 1

把this换成MainActivity.this，因为你是在匿名内部类使用this，你的this是指OnClickListener

Answer 2

this改成MainActivity.this

Answer 3

this改成MainActivity.this