Question

我对android开发很新，但知道一点Java。我在知道在我的代码中放置Toast.setGravity（Gravity.TOP，0,0）的位置时遇到了问题。

以下是代码：

package ca.ignitestudio.geoquiz;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;


public class QuizActivity extends AppCompatActivity {

private Button mTrueButton;
private Button mFalseButton;


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



    mTrueButton = (Button) findViewById(R.id.true_button);
    mTrueButton.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            Toast.makeText(QuizActivity.this, R.string.correct_toast, Toast.LENGTH_SHORT).show();
            Toast.setGravity(Gravity.TOP,0,0);
        }
    });
    mFalseButton = (Button) findViewById(R.id.false_button);
    mFalseButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(QuizActivity.this, R.string.incorrect_toast, Toast.LENGTH_SHORT).show();
        }
    });
}

}

Answer 1

您必须以这种方式调用setGravity：

 Toast toast = Toast.makeText(test.this,"bbb", Toast.LENGTH_LONG);
    toast.setGravity(Gravity.CENTER, 0, 0);
    toast.show();

Answer 2

setGravity不是静态方法，因此您应该在吐司实例上调用setGravity，即

Toast t = Toast.makeText(QuizActivity.this, R.string.correct_toast, Toast.LENGTH_SHORT); 
t.setGravity(Gravity.TOP,0,0); 
t.show();

Answer 3

您需要在实例上调用setGravity()，而不是在课程上调用Toast.makeText(QuizActivity.this, R.string.correct_toast, Toast.LENGTH_SHORT).show(); Toast.setGravity(Gravity.TOP,0,0);。变化

Toast toast = Toast.makeText(QuizActivity.this, R.string.correct_toast, Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP,0,0);
toast.show();

到

.csproj

非静态setGravity无法从静态上下文

3 个答案: