android - 在 View 下方显示 toast 小部件

Question

对于之前在这个项目上帮助过我的人，非常感谢!我的代码不再有任何问题，并且我进行了额外的调整。现在该应用程序实际上已经很强大了，我想再做一件事。

请参阅 layout 的屏幕截图在这里。

通常，toast View 出现在屏幕的底部中央。一旦调用 OnClick，我想让它显示在提交按钮的正下方 (8dp)。我怎样才能做到这一点。

查看我的 updated complete project在这里。

package com.lookjohn.guessnumber;

import java.util.Random;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
Random random; 
Button button;
EditText text;

int input; 
int MIN, MAX;
int comp; 
int guesses;

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    random = new Random();
    button = (Button)findViewById(R.id.button1);
    text = (EditText)findViewById(R.id.editText1);

    MIN = 1;
    MAX = 100;
    comp = random.nextInt(MAX - MIN + 1) + MIN; // Generate random number between 1 and 100.
    guesses = 0;

    button.setOnClickListener(myhandler1);
}

View.OnClickListener myhandler1 = new View.OnClickListener() {

    public void onClick(View v) {

        // Implemented max number of guesses, detect 
        // number of guesses and return from the method.

        String value = text.getText().toString(); // Get value from input from editTextView

        // If user submits an empty EditText, return to prevent a crash.
        if (value.isEmpty()) {
            Toast.makeText(MainActivity.this, "You must enter a guess!", Toast.LENGTH_SHORT);
            return;
        }

        input = Integer.parseInt(value); // Turn string into integer
        guesses++;
        if (input > 100) {
            Toast.makeText(MainActivity.this, 
                "That number is greater than 100. Not Valid!", 
                Toast.LENGTH_SHORT).show();
                return;
            }

        else if (input < comp)
            Toast.makeText(MainActivity.this, 
                "Your number is too small.", 
                Toast.LENGTH_SHORT).show();
        else if (input > comp) 
            Toast.makeText(MainActivity.this, 
                "Your number is too big.", 
                Toast.LENGTH_SHORT).show();
        else
            Toast.makeText(MainActivity.this, 
                "Good job! The answer was " + comp + ".\n" +
                "You made " + guesses + " guesses.\n" +
                "Restart the app to try again.", 
                Toast.LENGTH_LONG).show();
    }
};

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

Answer 1

android.widget.Toast 定义了一组有用的方法，允许自定义 toast 通知的外观和感觉。您应该研究的方法是 setGravity(int, int, int) .使用 0 偏移量，下面的代码会将 toast 顶部锚定到所提供 View 的底部，并将 toast 中心锚定到 View 的中心。

public static void positionToast(Toast toast, View view, Window window, int offsetX, int offsetY) {
    // toasts are positioned relatively to decor view, views relatively to their parents, we have to gather additional data to have a common coordinate system
    Rect rect = new Rect();
    window.getDecorView().getWindowVisibleDisplayFrame(rect);
    // covert anchor view absolute position to a position which is relative to decor view
    int[] viewLocation = new int[2];
    view.getLocationInWindow(viewLocation);
    int viewLeft = viewLocation[0] - rect.left;
    int viewTop = viewLocation[1] - rect.top;

    // measure toast to center it relatively to the anchor view
    DisplayMetrics metrics = new DisplayMetrics();
    window.getWindowManager().getDefaultDisplay().getMetrics(metrics);
    int widthMeasureSpec = MeasureSpec.makeMeasureSpec(metrics.widthPixels, MeasureSpec.UNSPECIFIED);
    int heightMeasureSpec = MeasureSpec.makeMeasureSpec(metrics.heightPixels, MeasureSpec.UNSPECIFIED);
    toast.getView().measure(widthMeasureSpec, heightMeasureSpec);
    int toastWidth = toast.getView().getMeasuredWidth();

    // compute toast offsets
    int toastX = viewLeft + (view.getWidth() - toastWidth) / 2 + offsetX;
    int toastY = viewTop + view.getHeight() + offsetY;

    toast.setGravity(Gravity.LEFT | Gravity.TOP, toastX, toastY);
}

使用它需要在您的onClick 方法中修改与 toast 相关的行:

int offsetY = getResources().getDimensionPixelSize(R.dimen.toast_offset_y);

Toast toast = Toast.makeText(MainActivity.this, "That number is greater than 100. Not Valid!", Toast.LENGTH_SHORT);
positionToast(toast, v, getWindow(), 0, offsetY);
toast.show();